From d333f672aec553e892a93d6dd1082c543f31d2e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:38:53 +0700
Subject: git-checkout.txt: spell out --no-option
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It's easier to search for and also less cryptic.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index f179b43..99c8c0d 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -118,7 +118,8 @@ OPTIONS
 --quiet::
 	Quiet, suppress feedback messages.
 
---[no-]progress::
+--progress::
+--no-progress::
 	Progress status is reported on the standard error stream
 	by default when it is attached to a terminal, unless `--quiet`
 	is specified. This flag enables progress reporting even if not
@@ -262,7 +263,7 @@ edits from your current working tree. See the ``Interactive Mode''
 section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
 +
 Note that this option uses the no overlay mode by default (see also
-`--[no-]overlay`), and currently doesn't support overlay mode.
+`--overlay`), and currently doesn't support overlay mode.
 
 --ignore-other-worktrees::
 	`git checkout` refuses when the wanted ref is already checked
@@ -270,7 +271,8 @@ Note that this option uses the no overlay mode by default (see also
 	out anyway. In other words, the ref can be held by more than one
 	worktree.
 
---[no-]recurse-submodules::
+--recurse-submodules::
+--no-recurse-submodules::
 	Using --recurse-submodules will update the content of all initialized
 	submodules according to the commit recorded in the superproject. If
 	local modifications in a submodule would be overwritten the checkout
@@ -283,7 +285,8 @@ Note that this option uses the no overlay mode by default (see also
 	Do not attempt to create a branch if a remote tracking branch
 	of the same name exists.
 
---[no-]overlay::
+--overlay::
+--no-overlay::
 	In the default overlay mode, `git checkout` never
 	removes files from the index or the working tree.  When
 	specifying `--no-overlay`, files that appear in the index and
-- 
cgit v0.10.2-6-g49f6


From 37f80025cdc5c2fe98039d45678f8ca9c7e36b93 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:38:54 +0700
Subject: git-checkout.txt: fix one syntax line
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

<branch> can be omitted in this syntax, and it's actually documented a
few paragraphs down:

  You could omit <branch>, in which case the command degenerates to
  "check out the current branch", which is a glorified no-op with
  rather expensive side-effects to show only the tracking information,
  if exists, for the current branch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 99c8c0d..28817cf 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -23,7 +23,7 @@ or the specified tree.  If no paths are given, 'git checkout' will
 also update `HEAD` to set the specified branch as the current
 branch.
 
-'git checkout' <branch>::
+'git checkout' [<branch>]::
 	To prepare for working on <branch>, switch to it by updating
 	the index and the files in the working tree, and by pointing
 	HEAD at the branch. Local modifications to the files in the
-- 
cgit v0.10.2-6-g49f6


From 9d223d43e5270a194902e2916ac0995cc1ba4524 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:38:55 +0700
Subject: doc: document --overwrite-ignore
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

I added this option in git-checkout and git-merge in c1d7036b6b
(checkout,merge: disallow overwriting ignored files with
--no-overwrite-ignore - 2011-11-27) but did not remember to update
documentation. This completes that commit.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 28817cf..5280d1f 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -271,6 +271,12 @@ Note that this option uses the no overlay mode by default (see also
 	out anyway. In other words, the ref can be held by more than one
 	worktree.
 
+--overwrite-ignore::
+--no-overwrite-ignore::
+	Silently overwrite ignored files when switching branches. This
+	is the default behavior. Use `--no-overwrite-ignore` to abort
+	the operation when the new branch contains ignored files.
+
 --recurse-submodules::
 --no-recurse-submodules::
 	Using --recurse-submodules will update the content of all initialized
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 4cc8646..6a9163d 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -87,6 +87,11 @@ will be appended to the specified message.
 	Allow the rerere mechanism to update the index with the
 	result of auto-conflict resolution if possible.
 
+--overwrite-ignore::
+--no-overwrite-ignore::
+	Silently overwrite ignored files from the merge result. This
+	is the default behavior. Use `--no-overwrite-ignore` to abort.
+
 --abort::
 	Abort the current conflict resolution process, and
 	try to reconstruct the pre-merge state.
-- 
cgit v0.10.2-6-g49f6


From 181e3725ecd12f5477d8581515fdbeb2469df1e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:38:56 +0700
Subject: git-checkout.txt: fix monospace typeset
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add backticks where we have none, replace single quotes with backticks
and replace double-quotes. Drop double-quotes from nested constructions
such as `"@{-1}"`.

Helped-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 5280d1f..bf90966 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -24,14 +24,14 @@ also update `HEAD` to set the specified branch as the current
 branch.
 
 'git checkout' [<branch>]::
-	To prepare for working on <branch>, switch to it by updating
+	To prepare for working on `<branch>`, switch to it by updating
 	the index and the files in the working tree, and by pointing
-	HEAD at the branch. Local modifications to the files in the
+	`HEAD` at the branch. Local modifications to the files in the
 	working tree are kept, so that they can be committed to the
-	<branch>.
+	`<branch>`.
 +
-If <branch> is not found but there does exist a tracking branch in
-exactly one remote (call it <remote>) with a matching name, treat as
+If `<branch>` is not found but there does exist a tracking branch in
+exactly one remote (call it `<remote>`) with a matching name, treat as
 equivalent to
 +
 ------------
@@ -47,7 +47,7 @@ branches from there if `<branch>` is ambiguous but exists on the
 'origin' remote. See also `checkout.defaultRemote` in
 linkgit:git-config[1].
 +
-You could omit <branch>, in which case the command degenerates to
+You could omit `<branch>`, in which case the command degenerates to
 "check out the current branch", which is a glorified no-op with
 rather expensive side-effects to show only the tracking information,
 if exists, for the current branch.
@@ -61,7 +61,7 @@ if exists, for the current branch.
 	`--track` without `-b` implies branch creation; see the
 	description of `--track` below.
 +
-If `-B` is given, <new_branch> is created if it doesn't exist; otherwise, it
+If `-B` is given, `<new_branch>` is created if it doesn't exist; otherwise, it
 is reset. This is the transactional equivalent of
 +
 ------------
@@ -75,25 +75,25 @@ successful.
 'git checkout' --detach [<branch>]::
 'git checkout' [--detach] <commit>::
 
-	Prepare to work on top of <commit>, by detaching HEAD at it
+	Prepare to work on top of `<commit>`, by detaching `HEAD` at it
 	(see "DETACHED HEAD" section), and updating the index and the
 	files in the working tree.  Local modifications to the files
 	in the working tree are kept, so that the resulting working
 	tree will be the state recorded in the commit plus the local
 	modifications.
 +
-When the <commit> argument is a branch name, the `--detach` option can
-be used to detach HEAD at the tip of the branch (`git checkout
-<branch>` would check out that branch without detaching HEAD).
+When the `<commit>` argument is a branch name, the `--detach` option can
+be used to detach `HEAD` at the tip of the branch (`git checkout
+<branch>` would check out that branch without detaching `HEAD`).
 +
-Omitting <branch> detaches HEAD at the tip of the current branch.
+Omitting `<branch>` detaches `HEAD` at the tip of the current branch.
 
 'git checkout' [<tree-ish>] [--] <pathspec>...::
 
 	Overwrite paths in the working tree by replacing with the
-	contents in the index or in the <tree-ish> (most often a
-	commit).  When a <tree-ish> is given, the paths that
-	match the <pathspec> are updated both in the index and in
+	contents in the index or in the `<tree-ish>` (most often a
+	commit).  When a `<tree-ish>` is given, the paths that
+	match the `<pathspec>` are updated both in the index and in
 	the working tree.
 +
 The index may contain unmerged entries because of a previous failed merge.
@@ -128,7 +128,7 @@ OPTIONS
 -f::
 --force::
 	When switching branches, proceed even if the index or the
-	working tree differs from HEAD.  This is used to throw away
+	working tree differs from `HEAD`.  This is used to throw away
 	local changes.
 +
 When checking out paths from the index, do not fail upon unmerged
@@ -155,12 +155,12 @@ on your side branch as `theirs` (i.e. "one contributor's work on top
 of it").
 
 -b <new_branch>::
-	Create a new branch named <new_branch> and start it at
-	<start_point>; see linkgit:git-branch[1] for details.
+	Create a new branch named `<new_branch>` and start it at
+	`<start_point>`; see linkgit:git-branch[1] for details.
 
 -B <new_branch>::
-	Creates the branch <new_branch> and start it at <start_point>;
-	if it already exists, then reset it to <start_point>. This is
+	Creates the branch `<new_branch>` and start it at `<start_point>`;
+	if it already exists, then reset it to `<start_point>`. This is
 	equivalent to running "git branch" with "-f"; see
 	linkgit:git-branch[1] for details.
 
@@ -173,15 +173,15 @@ If no `-b` option is given, the name of the new branch will be
 derived from the remote-tracking branch, by looking at the local part of
 the refspec configured for the corresponding remote, and then stripping
 the initial part up to the "*".
-This would tell us to use "hack" as the local branch when branching
-off of "origin/hack" (or "remotes/origin/hack", or even
-"refs/remotes/origin/hack").  If the given name has no slash, or the above
+This would tell us to use `hack` as the local branch when branching
+off of `origin/hack` (or `remotes/origin/hack`, or even
+`refs/remotes/origin/hack`).  If the given name has no slash, or the above
 guessing results in an empty name, the guessing is aborted.  You can
 explicitly give a name with `-b` in such a case.
 
 --no-track::
 	Do not set up "upstream" configuration, even if the
-	branch.autoSetupMerge configuration variable is true.
+	`branch.autoSetupMerge` configuration variable is true.
 
 -l::
 	Create the new branch's reflog; see linkgit:git-branch[1] for
@@ -190,21 +190,21 @@ explicitly give a name with `-b` in such a case.
 --detach::
 	Rather than checking out a branch to work on it, check out a
 	commit for inspection and discardable experiments.
-	This is the default behavior of "git checkout <commit>" when
-	<commit> is not a branch name.  See the "DETACHED HEAD" section
+	This is the default behavior of `git checkout <commit>` when
+	`<commit>` is not a branch name.  See the "DETACHED HEAD" section
 	below for details.
 
 --orphan <new_branch>::
-	Create a new 'orphan' branch, named <new_branch>, started from
-	<start_point> and switch to it.  The first commit made on this
+	Create a new 'orphan' branch, named `<new_branch>`, started from
+	`<start_point>` and switch to it.  The first commit made on this
 	new branch will have no parents and it will be the root of a new
 	history totally disconnected from all the other branches and
 	commits.
 +
 The index and the working tree are adjusted as if you had previously run
-"git checkout <start_point>".  This allows you to start a new history
-that records a set of paths similar to <start_point> by easily running
-"git commit -a" to make the root commit.
+`git checkout <start_point>`.  This allows you to start a new history
+that records a set of paths similar to `<start_point>` by easily running
+`git commit -a` to make the root commit.
 +
 This can be useful when you want to publish the tree from a commit
 without exposing its full history. You might want to do this to publish
@@ -213,17 +213,17 @@ whose full history contains proprietary or otherwise encumbered bits of
 code.
 +
 If you want to start a disconnected history that records a set of paths
-that is totally different from the one of <start_point>, then you should
+that is totally different from the one of `<start_point>`, then you should
 clear the index and the working tree right after creating the orphan
-branch by running "git rm -rf ." from the top level of the working tree.
+branch by running `git rm -rf .` from the top level of the working tree.
 Afterwards you will be ready to prepare your new files, repopulating the
 working tree, by copying them from elsewhere, extracting a tarball, etc.
 
 --ignore-skip-worktree-bits::
 	In sparse checkout mode, `git checkout -- <paths>` would
-	update only entries matched by <paths> and sparse patterns
-	in $GIT_DIR/info/sparse-checkout. This option ignores
-	the sparse patterns and adds back any files in <paths>.
+	update only entries matched by `<paths>` and sparse patterns
+	in `$GIT_DIR/info/sparse-checkout`. This option ignores
+	the sparse patterns and adds back any files in `<paths>`.
 
 -m::
 --merge::
@@ -245,18 +245,18 @@ When checking out paths from the index, this option lets you recreate
 the conflicted merge in the specified paths.
 
 --conflict=<style>::
-	The same as --merge option above, but changes the way the
+	The same as `--merge` option above, but changes the way the
 	conflicting hunks are presented, overriding the
-	merge.conflictStyle configuration variable.  Possible values are
+	`merge.conflictStyle` configuration variable.  Possible values are
 	"merge" (default) and "diff3" (in addition to what is shown by
 	"merge" style, shows the original contents).
 
 -p::
 --patch::
 	Interactively select hunks in the difference between the
-	<tree-ish> (or the index, if unspecified) and the working
+	`<tree-ish>` (or the index, if unspecified) and the working
 	tree.  The chosen hunks are then applied in reverse to the
-	working tree (and if a <tree-ish> was specified, the index).
+	working tree (and if a `<tree-ish>` was specified, the index).
 +
 This means that you can use `git checkout -p` to selectively discard
 edits from your current working tree. See the ``Interactive Mode''
@@ -279,13 +279,13 @@ Note that this option uses the no overlay mode by default (see also
 
 --recurse-submodules::
 --no-recurse-submodules::
-	Using --recurse-submodules will update the content of all initialized
+	Using `--recurse-submodules` will update the content of all initialized
 	submodules according to the commit recorded in the superproject. If
 	local modifications in a submodule would be overwritten the checkout
-	will fail unless `-f` is used. If nothing (or --no-recurse-submodules)
+	will fail unless `-f` is used. If nothing (or `--no-recurse-submodules`)
 	is used, the work trees of submodules will not be updated.
-	Just like linkgit:git-submodule[1], this will detach the
-	submodules HEAD.
+	Just like linkgit:git-submodule[1], this will detach `HEAD` of the
+	submodule.
 
 --no-guess::
 	Do not attempt to create a branch if a remote tracking branch
@@ -296,21 +296,21 @@ Note that this option uses the no overlay mode by default (see also
 	In the default overlay mode, `git checkout` never
 	removes files from the index or the working tree.  When
 	specifying `--no-overlay`, files that appear in the index and
-	working tree, but not in <tree-ish> are removed, to make them
-	match <tree-ish> exactly.
+	working tree, but not in `<tree-ish>` are removed, to make them
+	match `<tree-ish>` exactly.
 
 <branch>::
 	Branch to checkout; if it refers to a branch (i.e., a name that,
 	when prepended with "refs/heads/", is a valid ref), then that
 	branch is checked out. Otherwise, if it refers to a valid
-	commit, your HEAD becomes "detached" and you are no longer on
+	commit, your `HEAD` becomes "detached" and you are no longer on
 	any branch (see below for details).
 +
-You can use the `"@{-N}"` syntax to refer to the N-th last
+You can use the `@{-N}` syntax to refer to the N-th last
 branch/commit checked out using "git checkout" operation. You may
-also specify `-` which is synonymous to `"@{-1}"`.
+also specify `-` which is synonymous to `@{-1}`.
 +
-As a special case, you may use `"A...B"` as a shortcut for the
+As a special case, you may use `A...B` as a shortcut for the
 merge base of `A` and `B` if there is exactly one merge base. You can
 leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 
@@ -319,7 +319,7 @@ leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 
 <start_point>::
 	The name of a commit at which to start the new branch; see
-	linkgit:git-branch[1] for details. Defaults to HEAD.
+	linkgit:git-branch[1] for details. Defaults to `HEAD`.
 
 <tree-ish>::
 	Tree to checkout from (when paths are given). If not specified,
@@ -329,9 +329,9 @@ leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
 
 DETACHED HEAD
 -------------
-HEAD normally refers to a named branch (e.g. 'master'). Meanwhile, each
+`HEAD` normally refers to a named branch (e.g. `master`). Meanwhile, each
 branch refers to a specific commit. Let's look at a repo with three
-commits, one of them tagged, and with branch 'master' checked out:
+commits, one of them tagged, and with branch `master` checked out:
 
 ------------
            HEAD (refers to branch 'master')
@@ -344,10 +344,10 @@ a---b---c  branch 'master' (refers to commit 'c')
 ------------
 
 When a commit is created in this state, the branch is updated to refer to
-the new commit. Specifically, 'git commit' creates a new commit 'd', whose
-parent is commit 'c', and then updates branch 'master' to refer to new
-commit 'd'. HEAD still refers to branch 'master' and so indirectly now refers
-to commit 'd':
+the new commit. Specifically, 'git commit' creates a new commit `d`, whose
+parent is commit `c`, and then updates branch `master` to refer to new
+commit `d`. `HEAD` still refers to branch `master` and so indirectly now refers
+to commit `d`:
 
 ------------
 $ edit; git add; git commit
@@ -364,7 +364,7 @@ a---b---c---d  branch 'master' (refers to commit 'd')
 It is sometimes useful to be able to checkout a commit that is not at
 the tip of any named branch, or even to create a new commit that is not
 referenced by a named branch. Let's look at what happens when we
-checkout commit 'b' (here we show two ways this may be done):
+checkout commit `b` (here we show two ways this may be done):
 
 ------------
 $ git checkout v2.0  # or
@@ -379,9 +379,9 @@ a---b---c---d  branch 'master' (refers to commit 'd')
   tag 'v2.0' (refers to commit 'b')
 ------------
 
-Notice that regardless of which checkout command we use, HEAD now refers
-directly to commit 'b'. This is known as being in detached HEAD state.
-It means simply that HEAD refers to a specific commit, as opposed to
+Notice that regardless of which checkout command we use, `HEAD` now refers
+directly to commit `b`. This is known as being in detached `HEAD` state.
+It means simply that `HEAD` refers to a specific commit, as opposed to
 referring to a named branch. Let's see what happens when we create a commit:
 
 ------------
@@ -398,7 +398,7 @@ a---b---c---d  branch 'master' (refers to commit 'd')
   tag 'v2.0' (refers to commit 'b')
 ------------
 
-There is now a new commit 'e', but it is referenced only by HEAD. We can
+There is now a new commit `e`, but it is referenced only by `HEAD`. We can
 of course add yet another commit in this state:
 
 ------------
@@ -416,7 +416,7 @@ a---b---c---d  branch 'master' (refers to commit 'd')
 ------------
 
 In fact, we can perform all the normal Git operations. But, let's look
-at what happens when we then checkout master:
+at what happens when we then checkout `master`:
 
 ------------
 $ git checkout master
@@ -431,9 +431,9 @@ a---b---c---d  branch 'master' (refers to commit 'd')
 ------------
 
 It is important to realize that at this point nothing refers to commit
-'f'. Eventually commit 'f' (and by extension commit 'e') will be deleted
+`f`. Eventually commit `f` (and by extension commit `e`) will be deleted
 by the routine Git garbage collection process, unless we create a reference
-before that happens. If we have not yet moved away from commit 'f',
+before that happens. If we have not yet moved away from commit `f`,
 any of these will create a reference to it:
 
 ------------
@@ -442,19 +442,19 @@ $ git branch foo        <2>
 $ git tag foo           <3>
 ------------
 
-<1> creates a new branch 'foo', which refers to commit 'f', and then
-    updates HEAD to refer to branch 'foo'. In other words, we'll no longer
-    be in detached HEAD state after this command.
+<1> creates a new branch `foo`, which refers to commit `f`, and then
+    updates `HEAD` to refer to branch `foo`. In other words, we'll no longer
+    be in detached `HEAD` state after this command.
 
-<2> similarly creates a new branch 'foo', which refers to commit 'f',
-    but leaves HEAD detached.
+<2> similarly creates a new branch `foo`, which refers to commit `f`,
+    but leaves `HEAD` detached.
 
-<3> creates a new tag 'foo', which refers to commit 'f',
-    leaving HEAD detached.
+<3> creates a new tag `foo`, which refers to commit `f`,
+    leaving `HEAD` detached.
 
-If we have moved away from commit 'f', then we must first recover its object
+If we have moved away from commit `f`, then we must first recover its object
 name (typically by using git reflog), and then we can create a reference to
-it. For example, to see the last two commits to which HEAD referred, we
+it. For example, to see the last two commits to which `HEAD` referred, we
 can use either of these commands:
 
 ------------
@@ -465,12 +465,12 @@ $ git log -g -2 HEAD
 ARGUMENT DISAMBIGUATION
 -----------------------
 
-When there is only one argument given and it is not `--` (e.g. "git
-checkout abc"), and when the argument is both a valid `<tree-ish>`
-(e.g. a branch "abc" exists) and a valid `<pathspec>` (e.g. a file
+When there is only one argument given and it is not `--` (e.g. `git
+checkout abc`), and when the argument is both a valid `<tree-ish>`
+(e.g. a branch `abc` exists) and a valid `<pathspec>` (e.g. a file
 or a directory whose name is "abc" exists), Git would usually ask
 you to disambiguate.  Because checking out a branch is so common an
-operation, however, "git checkout abc" takes "abc" as a `<tree-ish>`
+operation, however, `git checkout abc` takes "abc" as a `<tree-ish>`
 in such a situation.  Use `git checkout -- <pathspec>` if you want
 to checkout these paths out of the index.
 
@@ -478,7 +478,7 @@ EXAMPLES
 --------
 
 . The following sequence checks out the `master` branch, reverts
-  the `Makefile` to two revisions back, deletes hello.c by
+  the `Makefile` to two revisions back, deletes `hello.c` by
   mistake, and gets it back from the index.
 +
 ------------
@@ -490,7 +490,7 @@ $ git checkout hello.c            <3>
 +
 <1> switch branch
 <2> take a file out of another commit
-<3> restore hello.c from the index
+<3> restore `hello.c` from the index
 +
 If you want to check out _all_ C source files out of the index,
 you can say
@@ -519,7 +519,7 @@ $ git checkout -- hello.c
 $ git checkout mytopic
 ------------
 +
-However, your "wrong" branch and correct "mytopic" branch may
+However, your "wrong" branch and correct `mytopic` branch may
 differ in files that you have modified locally, in which case
 the above checkout would fail like this:
 +
-- 
cgit v0.10.2-6-g49f6


From c2a8c1dd001c9ea318f90abedfd56d364f91a2ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:38:57 +0700
Subject: t: rename t2014-switch.sh to t2014-checkout-switch.sh
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The old name does not really say that this is about 'checkout -b'. See
49d833dc07 (Revert "checkout branch: prime cache-tree fully" -
2009-05-12) for more information

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t2014-checkout-switch.sh b/t/t2014-checkout-switch.sh
new file mode 100755
index 0000000..ccfb147
--- /dev/null
+++ b/t/t2014-checkout-switch.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+test_description='Peter MacMillan'
+. ./test-lib.sh
+
+test_expect_success setup '
+	echo Hello >file &&
+	git add file &&
+	test_tick &&
+	git commit -m V1 &&
+	echo Hello world >file &&
+	git add file &&
+	git checkout -b other
+'
+
+test_expect_success 'check all changes are staged' '
+	git diff --exit-code
+'
+
+test_expect_success 'second commit' '
+	git commit -m V2
+'
+
+test_expect_success 'check' '
+	git diff --cached --exit-code
+'
+
+test_done
diff --git a/t/t2014-switch.sh b/t/t2014-switch.sh
deleted file mode 100755
index ccfb147..0000000
--- a/t/t2014-switch.sh
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/bin/sh
-
-test_description='Peter MacMillan'
-. ./test-lib.sh
-
-test_expect_success setup '
-	echo Hello >file &&
-	git add file &&
-	test_tick &&
-	git commit -m V1 &&
-	echo Hello world >file &&
-	git add file &&
-	git checkout -b other
-'
-
-test_expect_success 'check all changes are staged' '
-	git diff --exit-code
-'
-
-test_expect_success 'second commit' '
-	git commit -m V2
-'
-
-test_expect_success 'check' '
-	git diff --cached --exit-code
-'
-
-test_done
-- 
cgit v0.10.2-6-g49f6


From af9ded5b7007a4fa9844be7ac1c86f7a6ef2e56a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:38:58 +0700
Subject: checkout: advice how to get out of detached HEAD mode
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Detached HEAD mode is considered dangerous and confusing for newcomers
and we print a big block of warning how to move forward. But we should
also suggest the user the way to get out of it if they get into detached
HEAD by mistake.

While at there, I also suggest how to turn the advice off. This is
another thing I find annoying with advices and should be dealt with in a
more generic way. But that may require some refactoring in advice.c
first.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/advice.c b/advice.c
index 567209a..b224825 100644
--- a/advice.c
+++ b/advice.c
@@ -191,13 +191,22 @@ void NORETURN die_conclude_merge(void)
 void detach_advice(const char *new_name)
 {
 	const char *fmt =
-	_("Note: checking out '%s'.\n\n"
+	_("Note: checking out '%s'.\n"
+	"\n"
 	"You are in 'detached HEAD' state. You can look around, make experimental\n"
 	"changes and commit them, and you can discard any commits you make in this\n"
-	"state without impacting any branches by performing another checkout.\n\n"
+	"state without impacting any branches by performing another checkout.\n"
+	"\n"
 	"If you want to create a new branch to retain commits you create, you may\n"
-	"do so (now or later) by using -b with the checkout command again. Example:\n\n"
-	"  git checkout -b <new-branch-name>\n\n");
+	"do so (now or later) by using -b with the checkout command again. Example:\n"
+	"\n"
+	"  git checkout -b <new-branch-name>\n"
+	"\n"
+	"Or undo this checkout with:\n"
+	"\n"
+	"  git checkout -\n"
+	"\n"
+	"Turn off this advice by setting config variable advice.detachedHead to false\n\n");
 
 	fprintf(stderr, fmt, new_name);
 }
diff --git a/t/t2020-checkout-detach.sh b/t/t2020-checkout-detach.sh
index 1fa6706..743c724 100755
--- a/t/t2020-checkout-detach.sh
+++ b/t/t2020-checkout-detach.sh
@@ -206,6 +206,12 @@ test_expect_success 'describe_detached_head prints no SHA-1 ellipsis when not as
 
 	  git checkout -b <new-branch-name>
 
+	Or undo this checkout with:
+
+	  git checkout -
+
+	Turn off this advice by setting config variable advice.detachedHead to false
+
 	HEAD is now at \$commit three
 	EOF
 
@@ -282,6 +288,12 @@ test_expect_success 'describe_detached_head does print SHA-1 ellipsis when asked
 
 	  git checkout -b <new-branch-name>
 
+	Or undo this checkout with:
+
+	  git checkout -
+
+	Turn off this advice by setting config variable advice.detachedHead to false
+
 	HEAD is now at \$commit... three
 	EOF
 
-- 
cgit v0.10.2-6-g49f6


From f4a4b9aca3cb70fabe3e856fa61ca35a99e2b8eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:38:59 +0700
Subject: checkout: inform the user when removing branch state
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

After a successful switch, if a merge, cherry-pick or revert is ongoing,
it is canceled. This behavior has been with us from the very early
beginning, soon after git-merge was created but never actually
documented [1]. It may be a good idea to be transparent and tell the
user if some operation is canceled.

I consider this a better way of telling the user than just adding a
sentence or two in git-checkout.txt, which will be mostly ignored
anyway.

PS. Originally I wanted to print more details like

    warning: cancelling an in-progress merge from <SHA-1>

which may allow some level of undo if the user wants to. But that seems
a lot more work. Perhaps it can be improved later if people still want
that.

[1] ... and I will try not to argue whether it is a sensible behavior.
There is some more discussion here if people are interested:
CACsJy8Axa5WsLSjiscjnxVK6jQHkfs-gH959=YtUvQkWriAk5w@mail.gmail.com

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/branch.c b/branch.c
index 28b81a7..8dd5bb9 100644
--- a/branch.c
+++ b/branch.c
@@ -337,11 +337,14 @@ void create_branch(struct repository *r,
 	free(real_ref);
 }
 
-void remove_branch_state(struct repository *r)
+void remove_branch_state(struct repository *r, int verbose)
 {
-	unlink(git_path_cherry_pick_head(r));
-	unlink(git_path_revert_head(r));
-	unlink(git_path_merge_head(r));
+	if (!unlink(git_path_cherry_pick_head(r)) && verbose)
+		warning(_("cancelling a cherry picking in progress"));
+	if (!unlink(git_path_revert_head(r)) && verbose)
+		warning(_("cancelling a revert in progress"));
+	if (!unlink(git_path_merge_head(r)) && verbose)
+		warning(_("cancelling a merge in progress"));
 	unlink(git_path_merge_rr(r));
 	unlink(git_path_merge_msg(r));
 	unlink(git_path_merge_mode(r));
diff --git a/branch.h b/branch.h
index 29c1afa..aed0459 100644
--- a/branch.h
+++ b/branch.h
@@ -64,7 +64,7 @@ extern int validate_new_branchname(const char *name, struct strbuf *ref, int for
  * Remove information about the state of working on the current
  * branch. (E.g., MERGE_HEAD)
  */
-void remove_branch_state(struct repository *r);
+void remove_branch_state(struct repository *r, int verbose);
 
 /*
  * Configure local branch "local" as downstream to branch "remote"
diff --git a/builtin/am.c b/builtin/am.c
index 4fb107a..99b6650 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1957,7 +1957,7 @@ static int clean_index(const struct object_id *head, const struct object_id *rem
 	if (merge_tree(remote_tree))
 		return -1;
 
-	remove_branch_state(the_repository);
+	remove_branch_state(the_repository, 0);
 
 	return 0;
 }
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 0e6037b..f66bd2f 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -899,7 +899,7 @@ static void update_refs_for_switch(const struct checkout_opts *opts,
 				delete_reflog(old_branch_info->path);
 		}
 	}
-	remove_branch_state(the_repository);
+	remove_branch_state(the_repository, !opts->quiet);
 	strbuf_release(&msg);
 	if (!opts->quiet &&
 	    (new_branch_info->path || (!opts->force_detach && !strcmp(new_branch_info->name, "HEAD"))))
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 52114cb..646d0f9 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1272,7 +1272,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
 			       NULL, NULL) < 0)
 			die(_("could not discard worktree changes"));
-		remove_branch_state(the_repository);
+		remove_branch_state(the_repository, 0);
 		if (read_basic_state(&options))
 			exit(1);
 		goto run_rebase;
@@ -1292,7 +1292,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			       NULL, NULL) < 0)
 			die(_("could not move back to %s"),
 			    oid_to_hex(&options.orig_head));
-		remove_branch_state(the_repository);
+		remove_branch_state(the_repository, 0);
 		ret = finish_rebase(&options);
 		goto cleanup;
 	}
diff --git a/builtin/reset.c b/builtin/reset.c
index 7882829..6d9397c 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -420,7 +420,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 			print_new_head_line(lookup_commit_reference(the_repository, &oid));
 	}
 	if (!pathspec.nr)
-		remove_branch_state(the_repository);
+		remove_branch_state(the_repository, 0);
 
 	return update_ref_status;
 }
diff --git a/builtin/revert.c b/builtin/revert.c
index a47b53c..ebf2789 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -196,7 +196,7 @@ static int run_sequencer(int argc, const char **argv, struct replay_opts *opts)
 	if (cmd == 'q') {
 		int ret = sequencer_remove_state(opts);
 		if (!ret)
-			remove_branch_state(the_repository);
+			remove_branch_state(the_repository, 0);
 		return ret;
 	}
 	if (cmd == 'c')
-- 
cgit v0.10.2-6-g49f6


From 0dabeffc16d3c8f7052a9a6d57c3f9f25cce3431 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:00 +0700
Subject: checkout: keep most #include sorted
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The include list becomes very long and frankly a bit unorganized. With
the exception of builtin.h, cache.h or git-compat-util.h which have to
come first, keep the rest sorted.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index f66bd2f..15ee518 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1,30 +1,30 @@
 #define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
-#include "config.h"
+#include "advice.h"
+#include "blob.h"
+#include "branch.h"
+#include "cache-tree.h"
 #include "checkout.h"
+#include "commit.h"
+#include "config.h"
+#include "diff.h"
+#include "dir.h"
+#include "ll-merge.h"
 #include "lockfile.h"
+#include "merge-recursive.h"
+#include "object-store.h"
 #include "parse-options.h"
 #include "refs.h"
-#include "object-store.h"
-#include "commit.h"
+#include "remote.h"
+#include "resolve-undo.h"
+#include "revision.h"
+#include "run-command.h"
+#include "submodule.h"
+#include "submodule-config.h"
 #include "tree.h"
 #include "tree-walk.h"
-#include "cache-tree.h"
 #include "unpack-trees.h"
-#include "dir.h"
-#include "run-command.h"
-#include "merge-recursive.h"
-#include "branch.h"
-#include "diff.h"
-#include "revision.h"
-#include "remote.h"
-#include "blob.h"
 #include "xdiff-interface.h"
-#include "ll-merge.h"
-#include "resolve-undo.h"
-#include "submodule-config.h"
-#include "submodule.h"
-#include "advice.h"
 
 static int checkout_optimize_new_branch;
 
-- 
cgit v0.10.2-6-g49f6


From 7ab4ad00ccb572574a6dfc73abfb3d5b724ab64e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:01 +0700
Subject: checkout: factor out some code in parse_branchname_arg()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This is in preparation for the new command restore, which also
needs to parse opts->source_tree but does not need all the
disambiguation logic.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 15ee518..897eefe 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1081,6 +1081,34 @@ static int git_checkout_config(const char *var, const char *value, void *cb)
 	return git_xmerge_config(var, value, NULL);
 }
 
+static void setup_new_branch_info_and_source_tree(
+	struct branch_info *new_branch_info,
+	struct checkout_opts *opts,
+	struct object_id *rev,
+	const char *arg)
+{
+	struct tree **source_tree = &opts->source_tree;
+	struct object_id branch_rev;
+
+	new_branch_info->name = arg;
+	setup_branch_path(new_branch_info);
+
+	if (!check_refname_format(new_branch_info->path, 0) &&
+	    !read_ref(new_branch_info->path, &branch_rev))
+		oidcpy(rev, &branch_rev);
+	else
+		new_branch_info->path = NULL; /* not an existing branch */
+
+	new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
+	if (!new_branch_info->commit) {
+		/* not a commit */
+		*source_tree = parse_tree_indirect(rev);
+	} else {
+		parse_commit_or_die(new_branch_info->commit);
+		*source_tree = get_commit_tree(new_branch_info->commit);
+	}
+}
+
 static int parse_branchname_arg(int argc, const char **argv,
 				int dwim_new_local_branch_ok,
 				struct branch_info *new_branch_info,
@@ -1088,10 +1116,8 @@ static int parse_branchname_arg(int argc, const char **argv,
 				struct object_id *rev,
 				int *dwim_remotes_matched)
 {
-	struct tree **source_tree = &opts->source_tree;
 	const char **new_branch = &opts->new_branch;
 	int argcount = 0;
-	struct object_id branch_rev;
 	const char *arg;
 	int dash_dash_pos;
 	int has_dash_dash = 0;
@@ -1213,26 +1239,11 @@ static int parse_branchname_arg(int argc, const char **argv,
 	argv++;
 	argc--;
 
-	new_branch_info->name = arg;
-	setup_branch_path(new_branch_info);
-
-	if (!check_refname_format(new_branch_info->path, 0) &&
-	    !read_ref(new_branch_info->path, &branch_rev))
-		oidcpy(rev, &branch_rev);
-	else
-		new_branch_info->path = NULL; /* not an existing branch */
+	setup_new_branch_info_and_source_tree(new_branch_info, opts, rev, arg);
 
-	new_branch_info->commit = lookup_commit_reference_gently(the_repository, rev, 1);
-	if (!new_branch_info->commit) {
-		/* not a commit */
-		*source_tree = parse_tree_indirect(rev);
-	} else {
-		parse_commit_or_die(new_branch_info->commit);
-		*source_tree = get_commit_tree(new_branch_info->commit);
-	}
-
-	if (!*source_tree)                   /* case (1): want a tree */
+	if (!opts->source_tree)                   /* case (1): want a tree */
 		die(_("reference is not a tree: %s"), arg);
+
 	if (!has_dash_dash) {	/* case (3).(d) -> (1) */
 		/*
 		 * Do not complain the most common case
-- 
cgit v0.10.2-6-g49f6


From b3edccb967ab4531e6a5fd20610a3be93be01c70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:02 +0700
Subject: checkout: make "opts" in cmd_checkout() a pointer
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"opts" will soon be moved out of cmd_checkout(). To keep changes in
that patch smaller, convert "opts" to a pointer and keep the real
thing behind "real_opts".

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 897eefe..b6de840 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1341,82 +1341,83 @@ static int checkout_branch(struct checkout_opts *opts,
 
 int cmd_checkout(int argc, const char **argv, const char *prefix)
 {
-	struct checkout_opts opts;
+	struct checkout_opts real_opts;
+	struct checkout_opts *opts = &real_opts;
 	struct branch_info new_branch_info;
 	char *conflict_style = NULL;
 	int dwim_new_local_branch, no_dwim_new_local_branch = 0;
 	int dwim_remotes_matched = 0;
 	struct option options[] = {
-		OPT__QUIET(&opts.quiet, N_("suppress progress reporting")),
-		OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
+		OPT__QUIET(&opts->quiet, N_("suppress progress reporting")),
+		OPT_STRING('b', NULL, &opts->new_branch, N_("branch"),
 			   N_("create and checkout a new branch")),
-		OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
+		OPT_STRING('B', NULL, &opts->new_branch_force, N_("branch"),
 			   N_("create/reset and checkout a branch")),
-		OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
-		OPT_BOOL(0, "detach", &opts.force_detach, N_("detach HEAD at named commit")),
-		OPT_SET_INT('t', "track",  &opts.track, N_("set upstream info for new branch"),
+		OPT_BOOL('l', NULL, &opts->new_branch_log, N_("create reflog for new branch")),
+		OPT_BOOL(0, "detach", &opts->force_detach, N_("detach HEAD at named commit")),
+		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
 			BRANCH_TRACK_EXPLICIT),
-		OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
-		OPT_SET_INT_F('2', "ours", &opts.writeout_stage,
+		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
+		OPT_SET_INT_F('2', "ours", &opts->writeout_stage,
 			      N_("checkout our version for unmerged files"),
 			      2, PARSE_OPT_NONEG),
-		OPT_SET_INT_F('3', "theirs", &opts.writeout_stage,
+		OPT_SET_INT_F('3', "theirs", &opts->writeout_stage,
 			      N_("checkout their version for unmerged files"),
 			      3, PARSE_OPT_NONEG),
-		OPT__FORCE(&opts.force, N_("force checkout (throw away local modifications)"),
+		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
 			   PARSE_OPT_NOCOMPLETE),
-		OPT_BOOL('m', "merge", &opts.merge, N_("perform a 3-way merge with the new branch")),
-		OPT_BOOL_F(0, "overwrite-ignore", &opts.overwrite_ignore,
+		OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
+		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
 			   N_("update ignored files (default)"),
 			   PARSE_OPT_NOCOMPLETE),
 		OPT_STRING(0, "conflict", &conflict_style, N_("style"),
 			   N_("conflict style (merge or diff3)")),
-		OPT_BOOL('p', "patch", &opts.patch_mode, N_("select hunks interactively")),
-		OPT_BOOL(0, "ignore-skip-worktree-bits", &opts.ignore_skipworktree,
+		OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
+		OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
 			 N_("do not limit pathspecs to sparse entries only")),
 		OPT_BOOL(0, "no-guess", &no_dwim_new_local_branch,
 			 N_("do not second guess 'git checkout <no-such-branch>'")),
-		OPT_BOOL(0, "ignore-other-worktrees", &opts.ignore_other_worktrees,
+		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
 			 N_("do not check if another worktree is holding the given ref")),
 		{ OPTION_CALLBACK, 0, "recurse-submodules", NULL,
 			    "checkout", "control recursive updating of submodules",
 			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
-		OPT_BOOL(0, "progress", &opts.show_progress, N_("force progress reporting")),
-		OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")),
+		OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
+		OPT_BOOL(0, "overlay", &opts->overlay_mode, N_("use overlay mode (default)")),
 		OPT_END(),
 	};
 
-	memset(&opts, 0, sizeof(opts));
+	memset(opts, 0, sizeof(*opts));
 	memset(&new_branch_info, 0, sizeof(new_branch_info));
-	opts.overwrite_ignore = 1;
-	opts.prefix = prefix;
-	opts.show_progress = -1;
-	opts.overlay_mode = -1;
+	opts->overwrite_ignore = 1;
+	opts->prefix = prefix;
+	opts->show_progress = -1;
+	opts->overlay_mode = -1;
 
-	git_config(git_checkout_config, &opts);
+	git_config(git_checkout_config, opts);
 
-	opts.track = BRANCH_TRACK_UNSPECIFIED;
+	opts->track = BRANCH_TRACK_UNSPECIFIED;
 
 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
 			     PARSE_OPT_KEEP_DASHDASH);
 
 	dwim_new_local_branch = !no_dwim_new_local_branch;
-	if (opts.show_progress < 0) {
-		if (opts.quiet)
-			opts.show_progress = 0;
+	if (opts->show_progress < 0) {
+		if (opts->quiet)
+			opts->show_progress = 0;
 		else
-			opts.show_progress = isatty(2);
+			opts->show_progress = isatty(2);
 	}
 
 	if (conflict_style) {
-		opts.merge = 1; /* implied */
+		opts->merge = 1; /* implied */
 		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
 	}
 
-	if ((!!opts.new_branch + !!opts.new_branch_force + !!opts.new_orphan_branch) > 1)
+	if ((!!opts->new_branch + !!opts->new_branch_force + !!opts->new_orphan_branch) > 1)
 		die(_("-b, -B and --orphan are mutually exclusive"));
 
-	if (opts.overlay_mode == 1 && opts.patch_mode)
+	if (opts->overlay_mode == 1 && opts->patch_mode)
 		die(_("-p and --overlay are mutually exclusive"));
 
 	/*
@@ -1424,14 +1425,14 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	 * and new_branch_force and new_orphan_branch will tell us which one of
 	 * -b/-B/--orphan is being used.
 	 */
-	if (opts.new_branch_force)
-		opts.new_branch = opts.new_branch_force;
+	if (opts->new_branch_force)
+		opts->new_branch = opts->new_branch_force;
 
-	if (opts.new_orphan_branch)
-		opts.new_branch = opts.new_orphan_branch;
+	if (opts->new_orphan_branch)
+		opts->new_branch = opts->new_orphan_branch;
 
 	/* --track without -b/-B/--orphan should DWIM */
-	if (opts.track != BRANCH_TRACK_UNSPECIFIED && !opts.new_branch) {
+	if (opts->track != BRANCH_TRACK_UNSPECIFIED && !opts->new_branch) {
 		const char *argv0 = argv[0];
 		if (!argc || !strcmp(argv0, "--"))
 			die(_("--track needs a branch name"));
@@ -1440,7 +1441,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		argv0 = strchr(argv0, '/');
 		if (!argv0 || !argv0[1])
 			die(_("missing branch name; try -b"));
-		opts.new_branch = argv0 + 1;
+		opts->new_branch = argv0 + 1;
 	}
 
 	/*
@@ -1459,56 +1460,56 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	if (argc) {
 		struct object_id rev;
 		int dwim_ok =
-			!opts.patch_mode &&
+			!opts->patch_mode &&
 			dwim_new_local_branch &&
-			opts.track == BRANCH_TRACK_UNSPECIFIED &&
-			!opts.new_branch;
+			opts->track == BRANCH_TRACK_UNSPECIFIED &&
+			!opts->new_branch;
 		int n = parse_branchname_arg(argc, argv, dwim_ok,
-					     &new_branch_info, &opts, &rev,
+					     &new_branch_info, opts, &rev,
 					     &dwim_remotes_matched);
 		argv += n;
 		argc -= n;
 	}
 
 	if (argc) {
-		parse_pathspec(&opts.pathspec, 0,
-			       opts.patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
+		parse_pathspec(&opts->pathspec, 0,
+			       opts->patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
 			       prefix, argv);
 
-		if (!opts.pathspec.nr)
+		if (!opts->pathspec.nr)
 			die(_("invalid path specification"));
 
 		/*
 		 * Try to give more helpful suggestion.
 		 * new_branch && argc > 1 will be caught later.
 		 */
-		if (opts.new_branch && argc == 1)
+		if (opts->new_branch && argc == 1)
 			die(_("'%s' is not a commit and a branch '%s' cannot be created from it"),
-				argv[0], opts.new_branch);
+				argv[0], opts->new_branch);
 
-		if (opts.force_detach)
+		if (opts->force_detach)
 			die(_("git checkout: --detach does not take a path argument '%s'"),
 			    argv[0]);
 
-		if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
+		if (1 < !!opts->writeout_stage + !!opts->force + !!opts->merge)
 			die(_("git checkout: --ours/--theirs, --force and --merge are incompatible when\n"
 			      "checking out of the index."));
 	}
 
-	if (opts.new_branch) {
+	if (opts->new_branch) {
 		struct strbuf buf = STRBUF_INIT;
 
-		if (opts.new_branch_force)
-			opts.branch_exists = validate_branchname(opts.new_branch, &buf);
+		if (opts->new_branch_force)
+			opts->branch_exists = validate_branchname(opts->new_branch, &buf);
 		else
-			opts.branch_exists =
-				validate_new_branchname(opts.new_branch, &buf, 0);
+			opts->branch_exists =
+				validate_new_branchname(opts->new_branch, &buf, 0);
 		strbuf_release(&buf);
 	}
 
 	UNLEAK(opts);
-	if (opts.patch_mode || opts.pathspec.nr) {
-		int ret = checkout_paths(&opts, new_branch_info.name);
+	if (opts->patch_mode || opts->pathspec.nr) {
+		int ret = checkout_paths(opts, new_branch_info.name);
 		if (ret && dwim_remotes_matched > 1 &&
 		    advice_checkout_ambiguous_remote_branch_name)
 			advise(_("'%s' matched more than one remote tracking branch.\n"
@@ -1527,6 +1528,6 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 			       dwim_remotes_matched);
 		return ret;
 	} else {
-		return checkout_branch(&opts, &new_branch_info);
+		return checkout_branch(opts, &new_branch_info);
 	}
 }
-- 
cgit v0.10.2-6-g49f6


From 55cf704a9d139bca0cb5cca1bf047eb043e13bd2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:03 +0700
Subject: checkout: move 'confict_style' and 'dwim_..' to checkout_opts
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

These local variables are referenced by struct option[]. This struct
will soon be broken down, moved away and we can't rely on local
variables anymore. Move these two to struct checkout_opts in
preparation for that.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index b6de840..93fc2a5 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -47,6 +47,8 @@ struct checkout_opts {
 	int show_progress;
 	int count_checkout_paths;
 	int overlay_mode;
+	int no_dwim_new_local_branch;
+
 	/*
 	 * If new checkout options are added, skip_merge_working_tree
 	 * should be updated accordingly.
@@ -58,6 +60,7 @@ struct checkout_opts {
 	int new_branch_log;
 	enum branch_track track;
 	struct diff_options diff_options;
+	char *conflict_style;
 
 	int branch_exists;
 	const char *prefix;
@@ -1344,8 +1347,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	struct checkout_opts real_opts;
 	struct checkout_opts *opts = &real_opts;
 	struct branch_info new_branch_info;
-	char *conflict_style = NULL;
-	int dwim_new_local_branch, no_dwim_new_local_branch = 0;
+	int dwim_new_local_branch;
 	int dwim_remotes_matched = 0;
 	struct option options[] = {
 		OPT__QUIET(&opts->quiet, N_("suppress progress reporting")),
@@ -1370,12 +1372,12 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
 			   N_("update ignored files (default)"),
 			   PARSE_OPT_NOCOMPLETE),
-		OPT_STRING(0, "conflict", &conflict_style, N_("style"),
+		OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
 			   N_("conflict style (merge or diff3)")),
 		OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
 		OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
 			 N_("do not limit pathspecs to sparse entries only")),
-		OPT_BOOL(0, "no-guess", &no_dwim_new_local_branch,
+		OPT_BOOL(0, "no-guess", &opts->no_dwim_new_local_branch,
 			 N_("do not second guess 'git checkout <no-such-branch>'")),
 		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
 			 N_("do not check if another worktree is holding the given ref")),
@@ -1393,6 +1395,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts->prefix = prefix;
 	opts->show_progress = -1;
 	opts->overlay_mode = -1;
+	opts->no_dwim_new_local_branch = 0;
 
 	git_config(git_checkout_config, opts);
 
@@ -1401,7 +1404,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
 			     PARSE_OPT_KEEP_DASHDASH);
 
-	dwim_new_local_branch = !no_dwim_new_local_branch;
+	dwim_new_local_branch = !opts->no_dwim_new_local_branch;
 	if (opts->show_progress < 0) {
 		if (opts->quiet)
 			opts->show_progress = 0;
@@ -1409,9 +1412,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 			opts->show_progress = isatty(2);
 	}
 
-	if (conflict_style) {
+	if (opts->conflict_style) {
 		opts->merge = 1; /* implied */
-		git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
+		git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
 	}
 
 	if ((!!opts->new_branch + !!opts->new_branch_force + !!opts->new_orphan_branch) > 1)
-- 
cgit v0.10.2-6-g49f6


From 208718227207480b0f58e35e045e36ed36a59205 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:04 +0700
Subject: checkout: split options[] array in three pieces
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This is a preparation step for introducing new commands that do parts
of what checkout does. There will be two new commands, one is about
switching branches, detaching HEAD... one about checking out
paths. These share the a subset of command line options. The rest of
command line options are separate.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 93fc2a5..c15dc91 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1342,15 +1342,31 @@ static int checkout_branch(struct checkout_opts *opts,
 	return switch_branches(opts, new_branch_info);
 }
 
-int cmd_checkout(int argc, const char **argv, const char *prefix)
+static struct option *add_common_options(struct checkout_opts *opts,
+					 struct option *prevopts)
 {
-	struct checkout_opts real_opts;
-	struct checkout_opts *opts = &real_opts;
-	struct branch_info new_branch_info;
-	int dwim_new_local_branch;
-	int dwim_remotes_matched = 0;
 	struct option options[] = {
 		OPT__QUIET(&opts->quiet, N_("suppress progress reporting")),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", NULL,
+			    "checkout", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
+		OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
+		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
+		OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
+			   N_("conflict style (merge or diff3)")),
+		OPT_END()
+	};
+	struct option *newopts = parse_options_concat(prevopts, options);
+	free(prevopts);
+	return newopts;
+}
+
+static struct option *add_switch_branch_options(struct checkout_opts *opts,
+						struct option *prevopts)
+{
+	struct option options[] = {
 		OPT_STRING('b', NULL, &opts->new_branch, N_("branch"),
 			   N_("create and checkout a new branch")),
 		OPT_STRING('B', NULL, &opts->new_branch_force, N_("branch"),
@@ -1360,34 +1376,49 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
 			BRANCH_TRACK_EXPLICIT),
 		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
+		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
+			   N_("update ignored files (default)"),
+			   PARSE_OPT_NOCOMPLETE),
+		OPT_BOOL(0, "no-guess", &opts->no_dwim_new_local_branch,
+			 N_("second guess 'git checkout <no-such-branch>'")),
+		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
+			 N_("do not check if another worktree is holding the given ref")),
+		OPT_END()
+	};
+	struct option *newopts = parse_options_concat(prevopts, options);
+	free(prevopts);
+	return newopts;
+}
+
+static struct option *add_checkout_path_options(struct checkout_opts *opts,
+						struct option *prevopts)
+{
+	struct option options[] = {
 		OPT_SET_INT_F('2', "ours", &opts->writeout_stage,
 			      N_("checkout our version for unmerged files"),
 			      2, PARSE_OPT_NONEG),
 		OPT_SET_INT_F('3', "theirs", &opts->writeout_stage,
 			      N_("checkout their version for unmerged files"),
 			      3, PARSE_OPT_NONEG),
-		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
-			   PARSE_OPT_NOCOMPLETE),
-		OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
-		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
-			   N_("update ignored files (default)"),
-			   PARSE_OPT_NOCOMPLETE),
-		OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
-			   N_("conflict style (merge or diff3)")),
 		OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
 		OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
 			 N_("do not limit pathspecs to sparse entries only")),
-		OPT_BOOL(0, "no-guess", &opts->no_dwim_new_local_branch,
-			 N_("do not second guess 'git checkout <no-such-branch>'")),
-		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
-			 N_("do not check if another worktree is holding the given ref")),
-		{ OPTION_CALLBACK, 0, "recurse-submodules", NULL,
-			    "checkout", "control recursive updating of submodules",
-			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
-		OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
 		OPT_BOOL(0, "overlay", &opts->overlay_mode, N_("use overlay mode (default)")),
-		OPT_END(),
+		OPT_END()
 	};
+	struct option *newopts = parse_options_concat(prevopts, options);
+	free(prevopts);
+	return newopts;
+}
+
+int cmd_checkout(int argc, const char **argv, const char *prefix)
+{
+	struct checkout_opts real_opts;
+	struct checkout_opts *opts = &real_opts;
+	struct branch_info new_branch_info;
+	int dwim_remotes_matched = 0;
+	int dwim_new_local_branch;
+	struct option *options = NULL;
 
 	memset(opts, 0, sizeof(*opts));
 	memset(&new_branch_info, 0, sizeof(new_branch_info));
@@ -1401,6 +1432,11 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 
 	opts->track = BRANCH_TRACK_UNSPECIFIED;
 
+	options = parse_options_dup(options);
+	options = add_common_options(opts, options);
+	options = add_switch_branch_options(opts, options);
+	options = add_checkout_path_options(opts, options);
+
 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
 			     PARSE_OPT_KEEP_DASHDASH);
 
diff --git a/parse-options-cb.c b/parse-options-cb.c
index 2733393..caaeed8 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -122,6 +122,23 @@ int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+struct option *parse_options_dup(const struct option *o)
+{
+	struct option *opts;
+	int nr = 0;
+
+	while (o && o->type != OPTION_END) {
+		nr++;
+		o++;
+	}
+
+	ALLOC_ARRAY(opts, nr + 1);
+	memcpy(opts, o - nr, sizeof(*o) * nr);
+	memset(opts + nr, 0, sizeof(*opts));
+	opts[nr].type = OPTION_END;
+	return opts;
+}
+
 struct option *parse_options_concat(struct option *a, struct option *b)
 {
 	struct option *ret;
diff --git a/parse-options.h b/parse-options.h
index 7d83e29..9a90c33 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -257,6 +257,7 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
 
 int parse_options_end(struct parse_opt_ctx_t *ctx);
 
+struct option *parse_options_dup(const struct option *a);
 struct option *parse_options_concat(struct option *a, struct option *b);
 
 /*----- some often used options -----*/
-- 
cgit v0.10.2-6-g49f6


From d787d311dbd7a4104a9dde23b90ae24528a15cf9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:05 +0700
Subject: checkout: split part of it to new command 'switch'
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"git checkout" doing too many things is a source of confusion for many
users (and it even bites old timers sometimes). To remedy that, the
command will be split into two new ones: switch and restore. The good
old "git checkout" command is still here and will be until all (or most
of users) are sick of it.

See the new man page for the final design of switch. The actual
implementation though is still pretty much the same as "git checkout"
and not completely aligned with the man page. Following patches will
adjust their behavior to match the man page.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/.gitignore b/.gitignore
index 7374587..c687b92 100644
--- a/.gitignore
+++ b/.gitignore
@@ -167,6 +167,7 @@
 /git-submodule
 /git-submodule--helper
 /git-svn
+/git-switch
 /git-symbolic-ref
 /git-tag
 /git-unpack-file
diff --git a/Documentation/config/advice.txt b/Documentation/config/advice.txt
index 8862042..239d479 100644
--- a/Documentation/config/advice.txt
+++ b/Documentation/config/advice.txt
@@ -42,7 +42,8 @@ advice.*::
 		state in the output of linkgit:git-status[1], in
 		the template shown when writing commit messages in
 		linkgit:git-commit[1], and in the help message shown
-		by linkgit:git-checkout[1] when switching branch.
+		by linkgit:git-switch[1] or
+		linkgit:git-checkout[1] when switching branch.
 	statusUoption::
 		Advise to consider using the `-u` option to linkgit:git-status[1]
 		when the command takes more than 2 seconds to enumerate untracked
@@ -62,12 +63,14 @@ advice.*::
 		your information is guessed from the system username and
 		domain name.
 	detachedHead::
-		Advice shown when you used linkgit:git-checkout[1] to
-		move to the detach HEAD state, to instruct how to create
-		a local branch after the fact.
+		Advice shown when you used
+		linkgit:git-switch[1] or linkgit:git-checkout[1]
+		to move to the detach HEAD state, to instruct how to
+		create a local branch after the fact.
 	checkoutAmbiguousRemoteBranchName::
 		Advice shown when the argument to
-		linkgit:git-checkout[1] ambiguously resolves to a
+		linkgit:git-checkout[1] and linkgit:git-switch[1]
+		ambiguously resolves to a
 		remote tracking branch on more than one remote in
 		situations where an unambiguous argument would have
 		otherwise caused a remote-tracking branch to be
diff --git a/Documentation/config/branch.txt b/Documentation/config/branch.txt
index 019d60e..8050466 100644
--- a/Documentation/config/branch.txt
+++ b/Documentation/config/branch.txt
@@ -1,5 +1,5 @@
 branch.autoSetupMerge::
-	Tells 'git branch' and 'git checkout' to set up new branches
+	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
 	so that linkgit:git-pull[1] will appropriately merge from the
 	starting point branch. Note that even if this option is not set,
 	this behavior can be chosen per-branch using the `--track`
@@ -11,7 +11,7 @@ branch.autoSetupMerge::
 	branch. This option defaults to true.
 
 branch.autoSetupRebase::
-	When a new branch is created with 'git branch' or 'git checkout'
+	When a new branch is created with 'git branch', 'git switch' or 'git checkout'
 	that tracks another branch, this variable tells Git to set
 	up pull to rebase instead of merge (see "branch.<name>.rebase").
 	When `never`, rebase is never automatically set to true.
diff --git a/Documentation/config/checkout.txt b/Documentation/config/checkout.txt
index c4118fa..d6872ff 100644
--- a/Documentation/config/checkout.txt
+++ b/Documentation/config/checkout.txt
@@ -1,5 +1,6 @@
 checkout.defaultRemote::
-	When you run 'git checkout <something>' and only have one
+	When you run 'git checkout <something>'
+	or 'git switch <something>' and only have one
 	remote, it may implicitly fall back on checking out and
 	tracking e.g. 'origin/<something>'. This stops working as soon
 	as you have more than one remote with a '<something>'
@@ -8,8 +9,10 @@ checkout.defaultRemote::
 	disambiguation. The typical use-case is to set this to
 	`origin`.
 +
-Currently this is used by linkgit:git-checkout[1] when 'git checkout
-<something>' will checkout the '<something>' branch on another remote,
+Currently this is used by linkgit:git-switch[1] and
+linkgit:git-checkout[1] when 'git checkout <something>'
+or 'git switch <something>'
+will checkout the '<something>' branch on another remote,
 and by linkgit:git-worktree[1] when 'git worktree add' refers to a
 remote branch. This setting might be used for other checkout-like
 commands or functionality in the future.
diff --git a/Documentation/config/diff.txt b/Documentation/config/diff.txt
index e48bb98..b3b304e 100644
--- a/Documentation/config/diff.txt
+++ b/Documentation/config/diff.txt
@@ -78,7 +78,8 @@ diff.external::
 diff.ignoreSubmodules::
 	Sets the default value of --ignore-submodules. Note that this
 	affects only 'git diff' Porcelain, and not lower level 'diff'
-	commands such as 'git diff-files'. 'git checkout' also honors
+	commands such as 'git diff-files'. 'git checkout'
+	and 'git switch' also honor
 	this setting when reporting uncommitted changes. Setting it to
 	'all' disables the submodule summary normally shown by 'git commit'
 	and 'git status' when `status.submoduleSummary` is set unless it is
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index bf90966..c7192bd 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -560,6 +560,10 @@ $ edit frotz
 $ git add frotz
 ------------
 
+SEE ALSO
+--------
+linkgit:git-switch[1]
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/Documentation/git-switch.txt b/Documentation/git-switch.txt
new file mode 100644
index 0000000..f15e5bd
--- /dev/null
+++ b/Documentation/git-switch.txt
@@ -0,0 +1,271 @@
+git-switch(1)
+=============
+
+NAME
+----
+git-switch - Switch branches
+
+SYNOPSIS
+--------
+[verse]
+'git switch' [<options>] [--no-guess] <branch>
+'git switch' [<options>] --detach [<start-point>]
+'git switch' [<options>] (-c|-C) <new-branch> [<start-point>]
+'git switch' [<options>] --orphan <new-branch>
+
+DESCRIPTION
+-----------
+Switch to a specified branch. The working tree and the index are
+updated to match the branch. All new commits will be added to the tip
+of this branch.
+
+Optionally a new branch could be created with either `-c`, `-C`,
+automatically from a remote branch of same name (see `--guess`), or
+detach the working tree from any branch with `--detach`, along with
+switching.
+
+Switching branches does not require a clean index and working tree
+(i.e. no differences compared to `HEAD`). The operation is aborted
+however if the operation leads to loss of local changes, unless told
+otherwise with `--discard-changes` or `--merge`.
+
+OPTIONS
+-------
+<branch>::
+	Branch to switch to.
+
+<new-branch>::
+	Name for the new branch.
+
+<start-point>::
+	The starting point for the new branch. Specifying a
+	`<start-point>` allows you to create a branch based on some
+	other point in history than where HEAD currently points. (Or,
+	in the case of `--detach`, allows you to inspect and detach
+	from some other point.)
++
+You can use the `@{-N}` syntax to refer to the N-th last
+branch/commit switched to using "git switch" or "git checkout"
+operation. You may also specify `-` which is synonymous to `@{-1}`.
+This is often used to switch quickly between two branches, or to undo
+a branch switch by mistake.
++
+As a special case, you may use `A...B` as a shortcut for the merge
+base of `A` and `B` if there is exactly one merge base. You can leave
+out at most one of `A` and `B`, in which case it defaults to `HEAD`.
+
+-c <new-branch>::
+--create <new-branch>::
+	Create a new branch named `<new-branch>` starting at
+	`<start-point>` before switching to the branch. This is a
+	convenient shortcut for:
++
+------------
+$ git branch <new-branch>
+$ git switch <new-branch>
+------------
+
+-C <new-branch>::
+--force-create <new-branch>::
+	Similar to `--create` except that if `<new-branch>` already
+	exists, it will be reset to `<start-point>`. This is a
+	convenient shortcut for:
++
+------------
+$ git branch -f <new-branch>
+$ git switch <new-branch>
+------------
+
+-d::
+--detach::
+	Switch to a commit for inspection and discardable
+	experiments. See the "DETACHED HEAD" section in
+	linkgit:git-checkout[1] for details.
+
+--guess::
+--no-guess::
+	If `<branch>` is not found but there does exist a tracking
+	branch in exactly one remote (call it `<remote>`) with a
+	matching name, treat as equivalent to
++
+------------
+$ git switch -c <branch> --track <remote>/<branch>
+------------
++
+If the branch exists in multiple remotes and one of them is named by
+the `checkout.defaultRemote` configuration variable, we'll use that
+one for the purposes of disambiguation, even if the `<branch>` isn't
+unique across all remotes. Set it to e.g. `checkout.defaultRemote=origin`
+to always checkout remote branches from there if `<branch>` is
+ambiguous but exists on the 'origin' remote. See also
+`checkout.defaultRemote` in linkgit:git-config[1].
++
+`--guess` is the default behavior. Use `--no-guess` to disable it.
+
+-f::
+--force::
+	An alias for `--discard-changes`.
+
+--discard-changes::
+	Proceed even if the index or the working tree differs from
+	`HEAD`. Both the index and working tree are restored to match
+	the switching target. If `--recurse-submodules` is specified,
+	submodule content is also restored to match the switching
+	target. This is used to throw away local changes.
+
+-m::
+--merge::
+	If you have local modifications to one or more files that are
+	different between the current branch and the branch to which
+	you are switching, the command refuses to switch branches in
+	order to preserve your modifications in context.  However,
+	with this option, a three-way merge between the current
+	branch, your working tree contents, and the new branch is
+	done, and you will be on the new branch.
++
+When a merge conflict happens, the index entries for conflicting
+paths are left unmerged, and you need to resolve the conflicts
+and mark the resolved paths with `git add` (or `git rm` if the merge
+should result in deletion of the path).
+
+--conflict=<style>::
+	The same as `--merge` option above, but changes the way the
+	conflicting hunks are presented, overriding the
+	`merge.conflictStyle` configuration variable.  Possible values are
+	"merge" (default) and "diff3" (in addition to what is shown by
+	"merge" style, shows the original contents).
+
+-q::
+--quiet::
+	Quiet, suppress feedback messages.
+
+--progress::
+--no-progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless `--quiet`
+	is specified. This flag enables progress reporting even if not
+	attached to a terminal, regardless of `--quiet`.
+
+-t::
+--track::
+	When creating a new branch, set up "upstream" configuration.
+	`-c` is implied. See `--track` in linkgit:git-branch[1] for
+	details.
++
+If no `-c` option is given, the name of the new branch will be derived
+from the remote-tracking branch, by looking at the local part of the
+refspec configured for the corresponding remote, and then stripping
+the initial part up to the "*".  This would tell us to use `hack` as
+the local branch when branching off of `origin/hack` (or
+`remotes/origin/hack`, or even `refs/remotes/origin/hack`).  If the
+given name has no slash, or the above guessing results in an empty
+name, the guessing is aborted.  You can explicitly give a name with
+`-c` in such a case.
+
+--no-track::
+	Do not set up "upstream" configuration, even if the
+	`branch.autoSetupMerge` configuration variable is true.
+
+--orphan <new-branch>::
+	Create a new 'orphan' branch, named `<new-branch>`. All
+	tracked files are removed.
+
+--ignore-other-worktrees::
+	`git switch` refuses when the wanted ref is already
+	checked out by another worktree. This option makes it check
+	the ref out anyway. In other words, the ref can be held by
+	more than one worktree.
+
+--recurse-submodules::
+--no-recurse-submodules::
+	Using `--recurse-submodules` will update the content of all
+	initialized submodules according to the commit recorded in the
+	superproject. If nothing (or `--no-recurse-submodules`) is
+	used, the work trees of submodules will not be updated. Just
+	like linkgit:git-submodule[1], this will detach `HEAD` of the
+	submodules.
+
+EXAMPLES
+--------
+
+The following command switches to the "master" branch:
+
+------------
+$ git switch master
+------------
+
+After working in the wrong branch, switching to the correct branch
+would be done using:
+
+------------
+$ git switch mytopic
+------------
+
+However, your "wrong" branch and correct "mytopic" branch may differ
+in files that you have modified locally, in which case the above
+switch would fail like this:
+
+------------
+$ git switch mytopic
+error: You have local changes to 'frotz'; not switching branches.
+------------
+
+You can give the `-m` flag to the command, which would try a three-way
+merge:
+
+------------
+$ git switch -m mytopic
+Auto-merging frotz
+------------
+
+After this three-way merge, the local modifications are _not_
+registered in your index file, so `git diff` would show you what
+changes you made since the tip of the new branch.
+
+To switch back to the previous branch before we switched to mytopic
+(i.e. "master" branch):
+
+------------
+$ git switch -
+------------
+
+You can grow a new branch from any commit. For example, switch to
+"HEAD~3" and create branch "fixup":
+
+------------
+$ git switch -c fixup HEAD~3
+Switched to a new branch 'fixup'
+------------
+
+If you want to start a new branch from a remote branch of the same
+name:
+
+------------
+$ git switch new-topic
+Branch 'new-topic' set up to track remote branch 'new-topic' from 'origin'
+Switched to a new branch 'new-topic'
+------------
+
+To check out commit `HEAD~3` for temporary inspection or experiment
+without creating a new branch:
+
+------------
+$ git switch --detach HEAD~3
+HEAD is now at 9fc9555312 Merge branch 'cc/shared-index-permbits'
+------------
+
+If it turns out whatever you have done is worth keeping, you can
+always create a new name for it (without switching away):
+
+------------
+$ git switch -c good-surprises
+------------
+
+SEE ALSO
+--------
+linkgit:git-checkout[1],
+linkgit:git-branch[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index bdd11a2..af16a35 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -112,7 +112,8 @@ Checking-out and checking-in
 
 These attributes affect how the contents stored in the
 repository are copied to the working tree files when commands
-such as 'git checkout' and 'git merge' run.  They also affect how
+such as 'git switch', 'git checkout'  and 'git merge' run.
+They also affect how
 Git stores the contents you prepare in the working tree in the
 repository upon 'git add' and 'git commit'.
 
diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
index 5bf653c..8ff72f0 100644
--- a/Documentation/githooks.txt
+++ b/Documentation/githooks.txt
@@ -165,12 +165,13 @@ rebased, and is not set when rebasing the current branch.
 post-checkout
 ~~~~~~~~~~~~~
 
-This hook is invoked when a linkgit:git-checkout[1] is run after having updated the
+This hook is invoked when a linkgit:git-checkout[1] or
+linkgit:git-switch[1] is run after having updated the
 worktree.  The hook is given three parameters: the ref of the previous HEAD,
 the ref of the new HEAD (which may or may not have changed), and a flag
 indicating whether the checkout was a branch checkout (changing branches,
 flag=1) or a file checkout (retrieving a file from the index, flag=0).
-This hook cannot affect the outcome of `git checkout`.
+This hook cannot affect the outcome of `git switch` or `git checkout`.
 
 It is also run after linkgit:git-clone[1], unless the `--no-checkout` (`-n`) option is
 used. The first parameter given to the hook is the null-ref, the second the
@@ -406,7 +407,8 @@ exit with a zero status.
 For example, the hook can simply run `git read-tree -u -m HEAD "$1"`
 in order to emulate `git fetch` that is run in the reverse direction
 with `git push`, as the two-tree form of `git read-tree -u -m` is
-essentially the same as `git checkout` that switches branches while
+essentially the same as `git switch` or `git checkout`
+that switches branches while
 keeping the local changes in the working tree that do not interfere
 with the difference between the branches.
 
diff --git a/Makefile b/Makefile
index 5374938..f85f364 100644
--- a/Makefile
+++ b/Makefile
@@ -802,6 +802,7 @@ BUILT_INS += git-merge-subtree$X
 BUILT_INS += git-show$X
 BUILT_INS += git-stage$X
 BUILT_INS += git-status$X
+BUILT_INS += git-switch$X
 BUILT_INS += git-whatchanged$X
 
 # what 'all' will build and 'install' will install in gitexecdir,
diff --git a/builtin.h b/builtin.h
index 6538932..c64e444 100644
--- a/builtin.h
+++ b/builtin.h
@@ -227,6 +227,7 @@ extern int cmd_show_index(int argc, const char **argv, const char *prefix);
 extern int cmd_status(int argc, const char **argv, const char *prefix);
 extern int cmd_stripspace(int argc, const char **argv, const char *prefix);
 extern int cmd_submodule__helper(int argc, const char **argv, const char *prefix);
+extern int cmd_switch(int argc, const char **argv, const char *prefix);
 extern int cmd_symbolic_ref(int argc, const char **argv, const char *prefix);
 extern int cmd_tag(int argc, const char **argv, const char *prefix);
 extern int cmd_tar_tree(int argc, const char **argv, const char *prefix);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index c15dc91..4989ca7 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -34,6 +34,11 @@ static const char * const checkout_usage[] = {
 	NULL,
 };
 
+static const char * const switch_branch_usage[] = {
+	N_("git switch [<options>] [<branch>]"),
+	NULL,
+};
+
 struct checkout_opts {
 	int patch_mode;
 	int quiet;
@@ -1411,33 +1416,25 @@ static struct option *add_checkout_path_options(struct checkout_opts *opts,
 	return newopts;
 }
 
-int cmd_checkout(int argc, const char **argv, const char *prefix)
+static int checkout_main(int argc, const char **argv, const char *prefix,
+			 struct checkout_opts *opts, struct option *options,
+			 const char * const usagestr[])
 {
-	struct checkout_opts real_opts;
-	struct checkout_opts *opts = &real_opts;
 	struct branch_info new_branch_info;
 	int dwim_remotes_matched = 0;
 	int dwim_new_local_branch;
-	struct option *options = NULL;
 
-	memset(opts, 0, sizeof(*opts));
 	memset(&new_branch_info, 0, sizeof(new_branch_info));
 	opts->overwrite_ignore = 1;
 	opts->prefix = prefix;
 	opts->show_progress = -1;
 	opts->overlay_mode = -1;
-	opts->no_dwim_new_local_branch = 0;
 
 	git_config(git_checkout_config, opts);
 
 	opts->track = BRANCH_TRACK_UNSPECIFIED;
 
-	options = parse_options_dup(options);
-	options = add_common_options(opts, options);
-	options = add_switch_branch_options(opts, options);
-	options = add_checkout_path_options(opts, options);
-
-	argc = parse_options(argc, argv, prefix, options, checkout_usage,
+	argc = parse_options(argc, argv, prefix, options, usagestr,
 			     PARSE_OPT_KEEP_DASHDASH);
 
 	dwim_new_local_branch = !opts->no_dwim_new_local_branch;
@@ -1570,3 +1567,42 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		return checkout_branch(opts, &new_branch_info);
 	}
 }
+
+int cmd_checkout(int argc, const char **argv, const char *prefix)
+{
+	struct checkout_opts opts;
+	struct option *options = NULL;
+	int ret;
+
+	memset(&opts, 0, sizeof(opts));
+	opts.no_dwim_new_local_branch = 0;
+
+	options = parse_options_dup(options);
+	options = add_common_options(&opts, options);
+	options = add_switch_branch_options(&opts, options);
+	options = add_checkout_path_options(&opts, options);
+
+	ret = checkout_main(argc, argv, prefix, &opts,
+			    options, checkout_usage);
+	FREE_AND_NULL(options);
+	return ret;
+}
+
+int cmd_switch(int argc, const char **argv, const char *prefix)
+{
+	struct checkout_opts opts;
+	struct option *options = NULL;
+	int ret;
+
+	memset(&opts, 0, sizeof(opts));
+	opts.no_dwim_new_local_branch = 0;
+
+	options = parse_options_dup(options);
+	options = add_common_options(&opts, options);
+	options = add_switch_branch_options(&opts, options);
+
+	ret = checkout_main(argc, argv, prefix, &opts,
+			    options, switch_branch_usage);
+	FREE_AND_NULL(options);
+	return ret;
+}
diff --git a/command-list.txt b/command-list.txt
index 3a9af10..13317f4 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -171,6 +171,7 @@ git-status                              mainporcelain           info
 git-stripspace                          purehelpers
 git-submodule                           mainporcelain
 git-svn                                 foreignscminterface
+git-switch                              mainporcelain           history
 git-symbolic-ref                        plumbingmanipulators
 git-tag                                 mainporcelain           history
 git-unpack-file                         plumbinginterrogators
diff --git a/git.c b/git.c
index 2014aab..39582cf 100644
--- a/git.c
+++ b/git.c
@@ -573,6 +573,7 @@ static struct cmd_struct commands[] = {
 	{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 	{ "stripspace", cmd_stripspace },
 	{ "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
+	{ "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
 	{ "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
 	{ "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
 	{ "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
-- 
cgit v0.10.2-6-g49f6


From b7b5fce2701c12895f75f8e716c629b45f105b0c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:06 +0700
Subject: switch: better names for -b and -B
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The shortcut of these options do not make much sense when used with
switch. And their descriptions are also tied to checkout. Move -b/-B
to cmd_checkout() and new -c/-C with the same functionality in
cmd_switch_branch()

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 4989ca7..319ba37 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1368,14 +1368,10 @@ static struct option *add_common_options(struct checkout_opts *opts,
 	return newopts;
 }
 
-static struct option *add_switch_branch_options(struct checkout_opts *opts,
-						struct option *prevopts)
+static struct option *add_common_switch_branch_options(
+	struct checkout_opts *opts, struct option *prevopts)
 {
 	struct option options[] = {
-		OPT_STRING('b', NULL, &opts->new_branch, N_("branch"),
-			   N_("create and checkout a new branch")),
-		OPT_STRING('B', NULL, &opts->new_branch_force, N_("branch"),
-			   N_("create/reset and checkout a branch")),
 		OPT_BOOL('l', NULL, &opts->new_branch_log, N_("create reflog for new branch")),
 		OPT_BOOL(0, "detach", &opts->force_detach, N_("detach HEAD at named commit")),
 		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
@@ -1571,15 +1567,22 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 int cmd_checkout(int argc, const char **argv, const char *prefix)
 {
 	struct checkout_opts opts;
-	struct option *options = NULL;
+	struct option *options;
+	struct option checkout_options[] = {
+		OPT_STRING('b', NULL, &opts.new_branch, N_("branch"),
+			   N_("create and checkout a new branch")),
+		OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
+			   N_("create/reset and checkout a branch")),
+		OPT_END()
+	};
 	int ret;
 
 	memset(&opts, 0, sizeof(opts));
 	opts.no_dwim_new_local_branch = 0;
 
-	options = parse_options_dup(options);
+	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
-	options = add_switch_branch_options(&opts, options);
+	options = add_common_switch_branch_options(&opts, options);
 	options = add_checkout_path_options(&opts, options);
 
 	ret = checkout_main(argc, argv, prefix, &opts,
@@ -1592,14 +1595,21 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 {
 	struct checkout_opts opts;
 	struct option *options = NULL;
+	struct option switch_options[] = {
+		OPT_STRING('c', "create", &opts.new_branch, N_("branch"),
+			   N_("create and switch to a new branch")),
+		OPT_STRING('C', "force-create", &opts.new_branch_force, N_("branch"),
+			   N_("create/reset and switch to a branch")),
+		OPT_END()
+	};
 	int ret;
 
 	memset(&opts, 0, sizeof(opts));
 	opts.no_dwim_new_local_branch = 0;
 
-	options = parse_options_dup(options);
+	options = parse_options_dup(switch_options);
 	options = add_common_options(&opts, options);
-	options = add_switch_branch_options(&opts, options);
+	options = add_common_switch_branch_options(&opts, options);
 
 	ret = checkout_main(argc, argv, prefix, &opts,
 			    options, switch_branch_usage);
-- 
cgit v0.10.2-6-g49f6


From 3ec37ad13dea55f6a614753accc7fad84cb170be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:07 +0700
Subject: switch: add --discard-changes
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

--discard-changes is a better name than --force for this option since
it's what really happens. --force is turned to an alias for
--discard-changes. But it's meant to be an alias for potentially more
force options in the future.

Side note. It's not obvious from the patch but --discard-changes also
affects submodules if --recurse-submodules is used. The knob to force
updating submodules is hidden behind unpack-trees.c

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 319ba37..6d0b2ef 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -53,6 +53,7 @@ struct checkout_opts {
 	int count_checkout_paths;
 	int overlay_mode;
 	int no_dwim_new_local_branch;
+	int discard_changes;
 
 	/*
 	 * If new checkout options are added, skip_merge_working_tree
@@ -680,7 +681,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		return error(_("index file corrupt"));
 
 	resolve_undo_clear();
-	if (opts->force) {
+	if (opts->discard_changes) {
 		ret = reset_tree(get_commit_tree(new_branch_info->commit),
 				 opts, 1, writeout_error);
 		if (ret)
@@ -802,7 +803,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
 
-	if (!opts->force && !opts->quiet)
+	if (!opts->discard_changes && !opts->quiet)
 		show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
 
 	return 0;
@@ -1309,6 +1310,9 @@ static int checkout_branch(struct checkout_opts *opts,
 	if (opts->force && opts->merge)
 		die(_("'%s' cannot be used with '%s'"), "-f", "-m");
 
+	if (opts->discard_changes && opts->merge)
+		die(_("'%s' cannot be used with '%s'"), "--discard-changes", "--merge");
+
 	if (opts->force_detach && opts->new_branch)
 		die(_("'%s' cannot be used with '%s'"),
 		    "--detach", "-b/-B/--orphan");
@@ -1445,6 +1449,8 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 		opts->merge = 1; /* implied */
 		git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
 	}
+	if (opts->force)
+		opts->discard_changes = 1;
 
 	if ((!!opts->new_branch + !!opts->new_branch_force + !!opts->new_orphan_branch) > 1)
 		die(_("-b, -B and --orphan are mutually exclusive"));
@@ -1600,6 +1606,8 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 			   N_("create and switch to a new branch")),
 		OPT_STRING('C', "force-create", &opts.new_branch_force, N_("branch"),
 			   N_("create/reset and switch to a branch")),
+		OPT_BOOL(0, "discard-changes", &opts.discard_changes,
+			 N_("throw away local modifications")),
 		OPT_END()
 	};
 	int ret;
-- 
cgit v0.10.2-6-g49f6


From 492ededc263e48d1a261dd694642ca53be4939e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:08 +0700
Subject: switch: remove -l
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This option is ancient. Nowadays reflog is enabled by default and
automatically created for new branches. Keep it in git-checkout only.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 6d0b2ef..d63116b 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1376,7 +1376,6 @@ static struct option *add_common_switch_branch_options(
 	struct checkout_opts *opts, struct option *prevopts)
 {
 	struct option options[] = {
-		OPT_BOOL('l', NULL, &opts->new_branch_log, N_("create reflog for new branch")),
 		OPT_BOOL(0, "detach", &opts->force_detach, N_("detach HEAD at named commit")),
 		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
 			BRANCH_TRACK_EXPLICIT),
@@ -1579,6 +1578,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 			   N_("create and checkout a new branch")),
 		OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
 			   N_("create/reset and checkout a branch")),
+		OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
 		OPT_END()
 	};
 	int ret;
-- 
cgit v0.10.2-6-g49f6


From 5c06e26903fd69cf7a71bf2cf8281a84868525b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:09 +0700
Subject: switch: stop accepting pathspec
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This command is about switching branch (or creating a new one) and
should not accept pathspec. This helps simplify ambiguation
handling. The other two ("git checkout" and "git restore") of
course do accept pathspec as before.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index d63116b..0584dc4 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -54,6 +54,7 @@ struct checkout_opts {
 	int overlay_mode;
 	int no_dwim_new_local_branch;
 	int discard_changes;
+	int accept_pathspec;
 
 	/*
 	 * If new checkout options are added, skip_merge_working_tree
@@ -1176,10 +1177,16 @@ static int parse_branchname_arg(int argc, const char **argv,
 	if (!argc)
 		return 0;
 
+	if (!opts->accept_pathspec) {
+		if (argc > 1)
+			die(_("only one reference expected"));
+		has_dash_dash = 1; /* helps disambiguate */
+	}
+
 	arg = argv[0];
 	dash_dash_pos = -1;
 	for (i = 0; i < argc; i++) {
-		if (!strcmp(argv[i], "--")) {
+		if (opts->accept_pathspec && !strcmp(argv[i], "--")) {
 			dash_dash_pos = i;
 			break;
 		}
@@ -1213,11 +1220,12 @@ static int parse_branchname_arg(int argc, const char **argv,
 			recover_with_dwim = 0;
 
 		/*
-		 * Accept "git checkout foo" and "git checkout foo --"
-		 * as candidates for dwim.
+		 * Accept "git checkout foo", "git checkout foo --"
+		 * and "git switch foo" as candidates for dwim.
 		 */
 		if (!(argc == 1 && !has_dash_dash) &&
-		    !(argc == 2 && has_dash_dash))
+		    !(argc == 2 && has_dash_dash) &&
+		    opts->accept_pathspec)
 			recover_with_dwim = 0;
 
 		if (recover_with_dwim) {
@@ -1262,7 +1270,7 @@ static int parse_branchname_arg(int argc, const char **argv,
 		 */
 		if (argc)
 			verify_non_filename(opts->prefix, arg);
-	} else {
+	} else if (opts->accept_pathspec) {
 		argcount++;
 		argv++;
 		argc--;
@@ -1585,6 +1593,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 
 	memset(&opts, 0, sizeof(opts));
 	opts.no_dwim_new_local_branch = 0;
+	opts.accept_pathspec = 1;
 
 	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
@@ -1614,6 +1623,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 
 	memset(&opts, 0, sizeof(opts));
 	opts.no_dwim_new_local_branch = 0;
+	opts.accept_pathspec = 0;
 
 	options = parse_options_dup(switch_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From e342c63a4e070bd1398b9aa86ac4ce917edbadc7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:10 +0700
Subject: switch: reject "do nothing" case
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"git checkout" can be executed without any arguments. What it does is
not exactly great: it switches from HEAD to HEAD and shows worktree
modification as a side effect.

Make switch reject this case. Just use "git status" if you want
that side effect. For switch, you have to either

- really switch a branch
- (explicitly) detach from the current branch
- create a new branch

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 0584dc4..e9dfe38 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -55,6 +55,7 @@ struct checkout_opts {
 	int no_dwim_new_local_branch;
 	int discard_changes;
 	int accept_pathspec;
+	int switch_branch_doing_nothing_is_ok;
 
 	/*
 	 * If new checkout options are added, skip_merge_working_tree
@@ -1338,6 +1339,12 @@ static int checkout_branch(struct checkout_opts *opts,
 		die(_("Cannot switch branch to a non-commit '%s'"),
 		    new_branch_info->name);
 
+	if (!opts->switch_branch_doing_nothing_is_ok &&
+	    !new_branch_info->name &&
+	    !opts->new_branch &&
+	    !opts->force_detach)
+		die(_("missing branch or commit argument"));
+
 	if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
 	    !opts->ignore_other_worktrees) {
 		int flag;
@@ -1593,6 +1600,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 
 	memset(&opts, 0, sizeof(opts));
 	opts.no_dwim_new_local_branch = 0;
+	opts.switch_branch_doing_nothing_is_ok = 1;
 	opts.accept_pathspec = 1;
 
 	options = parse_options_dup(checkout_options);
@@ -1624,6 +1632,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	memset(&opts, 0, sizeof(opts));
 	opts.no_dwim_new_local_branch = 0;
 	opts.accept_pathspec = 0;
+	opts.switch_branch_doing_nothing_is_ok = 0;
 
 	options = parse_options_dup(switch_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From 7968bef06b750fe9c59c1e1d0573bffc5b3cd94f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:11 +0700
Subject: switch: only allow explicit detached HEAD
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"git checkout <commit>" will checkout the commit in question and
detach HEAD from the current branch. It is naturally a right thing to
do once you get git references. But detached HEAD is a scary concept
to new users because we show a lot of warnings and stuff, and it could
be hard to get out of (until you know better).

To keep switch a bit more friendly to new users, we only allow
entering detached HEAD mode when --detach is given. "git
switch" must take a branch (unless you create a new branch,
then of course switch can take any commit-ish)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index e9dfe38..4416b82 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -45,6 +45,7 @@ struct checkout_opts {
 	int merge;
 	int force;
 	int force_detach;
+	int implicit_detach;
 	int writeout_stage;
 	int overwrite_ignore;
 	int ignore_skipworktree;
@@ -1298,6 +1299,29 @@ static int switch_unborn_to_new_branch(const struct checkout_opts *opts)
 	return status;
 }
 
+static void die_expecting_a_branch(const struct branch_info *branch_info)
+{
+	struct object_id oid;
+	char *to_free;
+
+	if (dwim_ref(branch_info->name, strlen(branch_info->name), &oid, &to_free) == 1) {
+		const char *ref = to_free;
+
+		if (skip_prefix(ref, "refs/tags/", &ref))
+			die(_("a branch is expected, got tag '%s'"), ref);
+		if (skip_prefix(ref, "refs/remotes/", &ref))
+			die(_("a branch is expected, got remote branch '%s'"), ref);
+		die(_("a branch is expected, got '%s'"), ref);
+	}
+	if (branch_info->commit)
+		die(_("a branch is expected, got commit '%s'"), branch_info->name);
+	/*
+	 * This case should never happen because we already die() on
+	 * non-commit, but just in case.
+	 */
+	die(_("a branch is expected, got '%s'"), branch_info->name);
+}
+
 static int checkout_branch(struct checkout_opts *opts,
 			   struct branch_info *new_branch_info)
 {
@@ -1345,6 +1369,14 @@ static int checkout_branch(struct checkout_opts *opts,
 	    !opts->force_detach)
 		die(_("missing branch or commit argument"));
 
+	if (!opts->implicit_detach &&
+	    !opts->force_detach &&
+	    !opts->new_branch &&
+	    !opts->new_branch_force &&
+	    new_branch_info->name &&
+	    !new_branch_info->path)
+		die_expecting_a_branch(new_branch_info);
+
 	if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
 	    !opts->ignore_other_worktrees) {
 		int flag;
@@ -1602,6 +1634,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.no_dwim_new_local_branch = 0;
 	opts.switch_branch_doing_nothing_is_ok = 1;
 	opts.accept_pathspec = 1;
+	opts.implicit_detach = 1;
 
 	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
@@ -1633,6 +1666,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	opts.no_dwim_new_local_branch = 0;
 	opts.accept_pathspec = 0;
 	opts.switch_branch_doing_nothing_is_ok = 0;
+	opts.implicit_detach = 0;
 
 	options = parse_options_dup(switch_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From 163e3b2975cf07e72c81df4bcdf3d74ae667f4d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:12 +0700
Subject: switch: add short option for --detach
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"git checkout" automatically detaches branches and --detach is not
that useful (--no-detach is more likely). But for "switch", you
may want to use it more often once you're used to detached HEAD. This
of course adds -d to git-checkout but it does not harm (yet?) to do it.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 4416b82..11308ab 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1423,7 +1423,7 @@ static struct option *add_common_switch_branch_options(
 	struct checkout_opts *opts, struct option *prevopts)
 {
 	struct option options[] = {
-		OPT_BOOL(0, "detach", &opts->force_detach, N_("detach HEAD at named commit")),
+		OPT_BOOL('d', "detach", &opts->force_detach, N_("detach HEAD at named commit")),
 		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
 			BRANCH_TRACK_EXPLICIT),
 		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
-- 
cgit v0.10.2-6-g49f6


From ccb111b342f472d12baddbfa5b52810da1725ffd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:13 +0700
Subject: switch: implicit dwim, use --no-guess to disable it
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This is already the default in git-checkout. The real change in here is
just minor cleanup. The main excuse is to explain why dwim is kept default.

Contrary to detach mode that is easy to get into and confusing to get
back out. Automatically creating a tracking branch often does not kick
in as often (you would need a branch of the same name on a remote). And
since the branch creation is reported clearly, the user should be able
to undo/delete it if it's unwanted.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index c7192bd..58f18a0 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -31,22 +31,13 @@ branch.
 	`<branch>`.
 +
 If `<branch>` is not found but there does exist a tracking branch in
-exactly one remote (call it `<remote>`) with a matching name, treat as
-equivalent to
+exactly one remote (call it `<remote>`) with a matching name and
+`--no-guess` is not specified, treat as equivalent to
 +
 ------------
 $ git checkout -b <branch> --track <remote>/<branch>
 ------------
 +
-If the branch exists in multiple remotes and one of them is named by
-the `checkout.defaultRemote` configuration variable, we'll use that
-one for the purposes of disambiguation, even if the `<branch>` isn't
-unique across all remotes. Set it to
-e.g. `checkout.defaultRemote=origin` to always checkout remote
-branches from there if `<branch>` is ambiguous but exists on the
-'origin' remote. See also `checkout.defaultRemote` in
-linkgit:git-config[1].
-+
 You could omit `<branch>`, in which case the command degenerates to
 "check out the current branch", which is a glorified no-op with
 rather expensive side-effects to show only the tracking information,
@@ -183,6 +174,27 @@ explicitly give a name with `-b` in such a case.
 	Do not set up "upstream" configuration, even if the
 	`branch.autoSetupMerge` configuration variable is true.
 
+--guess::
+--no-guess::
+	If `<branch>` is not found but there does exist a tracking
+	branch in exactly one remote (call it `<remote>`) with a
+	matching name, treat as equivalent to
++
+------------
+$ git checkout -b <branch> --track <remote>/<branch>
+------------
++
+If the branch exists in multiple remotes and one of them is named by
+the `checkout.defaultRemote` configuration variable, we'll use that
+one for the purposes of disambiguation, even if the `<branch>` isn't
+unique across all remotes. Set it to
+e.g. `checkout.defaultRemote=origin` to always checkout remote
+branches from there if `<branch>` is ambiguous but exists on the
+'origin' remote. See also `checkout.defaultRemote` in
+linkgit:git-config[1].
++
+Use `--no-guess` to disable this.
+
 -l::
 	Create the new branch's reflog; see linkgit:git-branch[1] for
 	details.
@@ -287,10 +299,6 @@ Note that this option uses the no overlay mode by default (see also
 	Just like linkgit:git-submodule[1], this will detach `HEAD` of the
 	submodule.
 
---no-guess::
-	Do not attempt to create a branch if a remote tracking branch
-	of the same name exists.
-
 --overlay::
 --no-overlay::
 	In the default overlay mode, `git checkout` never
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 11308ab..ff9b969 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -53,7 +53,7 @@ struct checkout_opts {
 	int show_progress;
 	int count_checkout_paths;
 	int overlay_mode;
-	int no_dwim_new_local_branch;
+	int dwim_new_local_branch;
 	int discard_changes;
 	int accept_pathspec;
 	int switch_branch_doing_nothing_is_ok;
@@ -1430,8 +1430,6 @@ static struct option *add_common_switch_branch_options(
 		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
 			   N_("update ignored files (default)"),
 			   PARSE_OPT_NOCOMPLETE),
-		OPT_BOOL(0, "no-guess", &opts->no_dwim_new_local_branch,
-			 N_("second guess 'git checkout <no-such-branch>'")),
 		OPT_BOOL(0, "ignore-other-worktrees", &opts->ignore_other_worktrees,
 			 N_("do not check if another worktree is holding the given ref")),
 		OPT_END()
@@ -1468,7 +1466,6 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 {
 	struct branch_info new_branch_info;
 	int dwim_remotes_matched = 0;
-	int dwim_new_local_branch;
 
 	memset(&new_branch_info, 0, sizeof(new_branch_info));
 	opts->overwrite_ignore = 1;
@@ -1483,7 +1480,6 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 	argc = parse_options(argc, argv, prefix, options, usagestr,
 			     PARSE_OPT_KEEP_DASHDASH);
 
-	dwim_new_local_branch = !opts->no_dwim_new_local_branch;
 	if (opts->show_progress < 0) {
 		if (opts->quiet)
 			opts->show_progress = 0;
@@ -1545,7 +1541,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 		struct object_id rev;
 		int dwim_ok =
 			!opts->patch_mode &&
-			dwim_new_local_branch &&
+			opts->dwim_new_local_branch &&
 			opts->track == BRANCH_TRACK_UNSPECIFIED &&
 			!opts->new_branch;
 		int n = parse_branchname_arg(argc, argv, dwim_ok,
@@ -1626,12 +1622,14 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		OPT_STRING('B', NULL, &opts.new_branch_force, N_("branch"),
 			   N_("create/reset and checkout a branch")),
 		OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
+		OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
+			 N_("second guess 'git checkout <no-such-branch>' (default)")),
 		OPT_END()
 	};
 	int ret;
 
 	memset(&opts, 0, sizeof(opts));
-	opts.no_dwim_new_local_branch = 0;
+	opts.dwim_new_local_branch = 1;
 	opts.switch_branch_doing_nothing_is_ok = 1;
 	opts.accept_pathspec = 1;
 	opts.implicit_detach = 1;
@@ -1656,6 +1654,8 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 			   N_("create and switch to a new branch")),
 		OPT_STRING('C', "force-create", &opts.new_branch_force, N_("branch"),
 			   N_("create/reset and switch to a branch")),
+		OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
+			 N_("second guess 'git switch <no-such-branch>'")),
 		OPT_BOOL(0, "discard-changes", &opts.discard_changes,
 			 N_("throw away local modifications")),
 		OPT_END()
@@ -1663,7 +1663,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	int ret;
 
 	memset(&opts, 0, sizeof(opts));
-	opts.no_dwim_new_local_branch = 0;
+	opts.dwim_new_local_branch = 1;
 	opts.accept_pathspec = 0;
 	opts.switch_branch_doing_nothing_is_ok = 0;
 	opts.implicit_detach = 0;
-- 
cgit v0.10.2-6-g49f6


From 65f099b3988198f0fdf3ef7a21dc01c556d21fff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:14 +0700
Subject: switch: no worktree status unless real branch switch happens
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When we switch from one branch to another, it makes sense to show a
summary of local changes since there could be conflicts, or some files
left modified.... When switch is used solely for creating a new
branch (and "switch" to the same commit) or detaching, we don't really
need to show anything.

"git checkout" does it anyway for historical reasons. But we can start
with a clean slate with switch and don't have to.

This essentially reverts fa655d8411 (checkout: optimize "git checkout
-b <new_branch>" - 2018-08-16) and make it default for switch,
but also for -B and --detach. Users of big repos are encouraged to
move to switch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config/checkout.txt b/Documentation/config/checkout.txt
index d6872ff..6b64681 100644
--- a/Documentation/config/checkout.txt
+++ b/Documentation/config/checkout.txt
@@ -16,11 +16,3 @@ will checkout the '<something>' branch on another remote,
 and by linkgit:git-worktree[1] when 'git worktree add' refers to a
 remote branch. This setting might be used for other checkout-like
 commands or functionality in the future.
-
-checkout.optimizeNewBranch::
-	Optimizes the performance of "git checkout -b <new_branch>" when
-	using sparse-checkout.  When set to true, git will not update the
-	repo based on the current sparse-checkout settings.  This means it
-	will not update the skip-worktree bit in the index nor add/remove
-	files in the working directory to reflect the current sparse checkout
-	settings nor will it show the local changes.
diff --git a/builtin/checkout.c b/builtin/checkout.c
index ff9b969..f7967cd 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -26,8 +26,6 @@
 #include "unpack-trees.h"
 #include "xdiff-interface.h"
 
-static int checkout_optimize_new_branch;
-
 static const char * const checkout_usage[] = {
 	N_("git checkout [<options>] <branch>"),
 	N_("git checkout [<options>] [<branch>] -- <file>..."),
@@ -57,11 +55,7 @@ struct checkout_opts {
 	int discard_changes;
 	int accept_pathspec;
 	int switch_branch_doing_nothing_is_ok;
-
-	/*
-	 * If new checkout options are added, skip_merge_working_tree
-	 * should be updated accordingly.
-	 */
+	int only_merge_on_switching_branches;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -565,112 +559,6 @@ static void setup_branch_path(struct branch_info *branch)
 	branch->path = strbuf_detach(&buf, NULL);
 }
 
-/*
- * Skip merging the trees, updating the index and working directory if and
- * only if we are creating a new branch via "git checkout -b <new_branch>."
- */
-static int skip_merge_working_tree(const struct checkout_opts *opts,
-	const struct branch_info *old_branch_info,
-	const struct branch_info *new_branch_info)
-{
-	/*
-	 * Do the merge if sparse checkout is on and the user has not opted in
-	 * to the optimized behavior
-	 */
-	if (core_apply_sparse_checkout && !checkout_optimize_new_branch)
-		return 0;
-
-	/*
-	 * We must do the merge if we are actually moving to a new commit.
-	 */
-	if (!old_branch_info->commit || !new_branch_info->commit ||
-		!oideq(&old_branch_info->commit->object.oid,
-		       &new_branch_info->commit->object.oid))
-		return 0;
-
-	/*
-	 * opts->patch_mode cannot be used with switching branches so is
-	 * not tested here
-	 */
-
-	/*
-	 * opts->quiet only impacts output so doesn't require a merge
-	 */
-
-	/*
-	 * Honor the explicit request for a three-way merge or to throw away
-	 * local changes
-	 */
-	if (opts->merge || opts->force)
-		return 0;
-
-	/*
-	 * --detach is documented as "updating the index and the files in the
-	 * working tree" but this optimization skips those steps so fall through
-	 * to the regular code path.
-	 */
-	if (opts->force_detach)
-		return 0;
-
-	/*
-	 * opts->writeout_stage cannot be used with switching branches so is
-	 * not tested here
-	 */
-
-	/*
-	 * Honor the explicit ignore requests
-	 */
-	if (!opts->overwrite_ignore || opts->ignore_skipworktree ||
-		opts->ignore_other_worktrees)
-		return 0;
-
-	/*
-	 * opts->show_progress only impacts output so doesn't require a merge
-	 */
-
-	/*
-	 * opts->overlay_mode cannot be used with switching branches so is
-	 * not tested here
-	 */
-
-	/*
-	 * If we aren't creating a new branch any changes or updates will
-	 * happen in the existing branch.  Since that could only be updating
-	 * the index and working directory, we don't want to skip those steps
-	 * or we've defeated any purpose in running the command.
-	 */
-	if (!opts->new_branch)
-		return 0;
-
-	/*
-	 * new_branch_force is defined to "create/reset and checkout a branch"
-	 * so needs to go through the merge to do the reset
-	 */
-	if (opts->new_branch_force)
-		return 0;
-
-	/*
-	 * A new orphaned branch requrires the index and the working tree to be
-	 * adjusted to <start_point>
-	 */
-	if (opts->new_orphan_branch)
-		return 0;
-
-	/*
-	 * Remaining variables are not checkout options but used to track state
-	 */
-
-	 /*
-	  * Do the merge if this is the initial checkout. We cannot use
-	  * is_cache_unborn() here because the index hasn't been loaded yet
-	  * so cache_nr and timestamp.sec are always zero.
-	  */
-	if (!file_exists(get_index_file()))
-		return 0;
-
-	return 1;
-}
-
 static int merge_working_tree(const struct checkout_opts *opts,
 			      struct branch_info *old_branch_info,
 			      struct branch_info *new_branch_info,
@@ -1028,6 +916,7 @@ static int switch_branches(const struct checkout_opts *opts,
 	void *path_to_free;
 	struct object_id rev;
 	int flag, writeout_error = 0;
+	int do_merge = 1;
 
 	trace2_cmd_mode("branch");
 
@@ -1047,16 +936,12 @@ static int switch_branches(const struct checkout_opts *opts,
 		if (!new_branch_info->commit)
 			die(_("You are on a branch yet to be born"));
 		parse_commit_or_die(new_branch_info->commit);
+
+		if (opts->only_merge_on_switching_branches)
+			do_merge = 0;
 	}
 
-	/* optimize the "checkout -b <new_branch> path */
-	if (skip_merge_working_tree(opts, &old_branch_info, new_branch_info)) {
-		if (!checkout_optimize_new_branch && !opts->quiet) {
-			if (read_cache_preload(NULL) < 0)
-				return error(_("index file corrupt"));
-			show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
-		}
-	} else {
+	if (do_merge) {
 		ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
 		if (ret) {
 			free(path_to_free);
@@ -1076,11 +961,6 @@ static int switch_branches(const struct checkout_opts *opts,
 
 static int git_checkout_config(const char *var, const char *value, void *cb)
 {
-	if (!strcmp(var, "checkout.optimizenewbranch")) {
-		checkout_optimize_new_branch = git_config_bool(var, value);
-		return 0;
-	}
-
 	if (!strcmp(var, "diff.ignoresubmodules")) {
 		struct checkout_opts *opts = cb;
 		handle_ignore_submodules_arg(&opts->diff_options, value);
@@ -1631,6 +1511,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	memset(&opts, 0, sizeof(opts));
 	opts.dwim_new_local_branch = 1;
 	opts.switch_branch_doing_nothing_is_ok = 1;
+	opts.only_merge_on_switching_branches = 0;
 	opts.accept_pathspec = 1;
 	opts.implicit_detach = 1;
 
@@ -1666,6 +1547,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	opts.dwim_new_local_branch = 1;
 	opts.accept_pathspec = 0;
 	opts.switch_branch_doing_nothing_is_ok = 0;
+	opts.only_merge_on_switching_branches = 1;
 	opts.implicit_detach = 0;
 
 	options = parse_options_dup(switch_options);
diff --git a/t/t1090-sparse-checkout-scope.sh b/t/t1090-sparse-checkout-scope.sh
index 090b7fc..40cc004 100755
--- a/t/t1090-sparse-checkout-scope.sh
+++ b/t/t1090-sparse-checkout-scope.sh
@@ -31,20 +31,6 @@ test_expect_success 'perform sparse checkout of master' '
 	test_path_is_file c
 '
 
-test_expect_success 'checkout -b checkout.optimizeNewBranch interaction' '
-	cp .git/info/sparse-checkout .git/info/sparse-checkout.bak &&
-	test_when_finished "
-		mv -f .git/info/sparse-checkout.bak .git/info/sparse-checkout
-		git checkout master
-	" &&
-	echo "/b" >>.git/info/sparse-checkout &&
-	test "$(git ls-files -t b)" = "S b" &&
-	git -c checkout.optimizeNewBranch=true checkout -b fast &&
-	test "$(git ls-files -t b)" = "S b" &&
-	git checkout -b slow &&
-	test "$(git ls-files -t b)" = "H b"
-'
-
 test_expect_success 'merge feature branch into sparse checkout of master' '
 	git merge feature &&
 	test_path_is_file a &&
-- 
cgit v0.10.2-6-g49f6


From c45f0f525de4701b8ff031d5c2c58c0fa819038e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:15 +0700
Subject: switch: reject if some operation is in progress
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Unless you know what you're doing, switching to another branch to do
something then switching back could be confusing. Worse, you may even
forget that you're in the middle of something. By the time you realize,
you may have done a ton of work and it gets harder to go back.

A new option --ignore-in-progress was considered but dropped because it
was not exactly clear what should happen. Sometimes you can switch away
and get back safely and resume the operation. Sometimes not. And the
git-checkout behavior is automatically clear merge/revert/cherry-pick,
which makes it a bit even more confusing [1].

We may revisit and add this option in the future. But for now play it
safe and not allow it (you can't even skip this check with --force). The
user is suggested to cancel the operation by themselves (and hopefully
they do consider the consequences, not blindly type the command), or to
create a separate worktree instead of switching. The third option is
the good old "git checkout", but it's not mentioned.

[1] CACsJy8Axa5WsLSjiscjnxVK6jQHkfs-gH959=YtUvQkWriAk5w@mail.gmail.com

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index f7967cd..5f100c1 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -24,6 +24,7 @@
 #include "tree.h"
 #include "tree-walk.h"
 #include "unpack-trees.h"
+#include "wt-status.h"
 #include "xdiff-interface.h"
 
 static const char * const checkout_usage[] = {
@@ -56,6 +57,7 @@ struct checkout_opts {
 	int accept_pathspec;
 	int switch_branch_doing_nothing_is_ok;
 	int only_merge_on_switching_branches;
+	int can_switch_when_in_progress;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -1202,6 +1204,39 @@ static void die_expecting_a_branch(const struct branch_info *branch_info)
 	die(_("a branch is expected, got '%s'"), branch_info->name);
 }
 
+static void die_if_some_operation_in_progress(void)
+{
+	struct wt_status_state state;
+
+	memset(&state, 0, sizeof(state));
+	wt_status_get_state(the_repository, &state, 0);
+
+	if (state.merge_in_progress)
+		die(_("cannot switch branch while merging\n"
+		      "Consider \"git merge --quit\" "
+		      "or \"git worktree add\"."));
+	if (state.am_in_progress)
+		die(_("cannot switch branch in the middle of an am session\n"
+		      "Consider \"git am --quit\" "
+		      "or \"git worktree add\"."));
+	if (state.rebase_interactive_in_progress || state.rebase_in_progress)
+		die(_("cannot switch branch while rebasing\n"
+		      "Consider \"git rebase --quit\" "
+		      "or \"git worktree add\"."));
+	if (state.cherry_pick_in_progress)
+		die(_("cannot switch branch while cherry-picking\n"
+		      "Consider \"git cherry-pick --quit\" "
+		      "or \"git worktree add\"."));
+	if (state.revert_in_progress)
+		die(_("cannot switch branch while reverting\n"
+		      "Consider \"git revert --quit\" "
+		      "or \"git worktree add\"."));
+	if (state.bisect_in_progress)
+		die(_("cannot switch branch while bisecting\n"
+		      "Consider \"git bisect reset HEAD\" "
+		      "or \"git worktree add\"."));
+}
+
 static int checkout_branch(struct checkout_opts *opts,
 			   struct branch_info *new_branch_info)
 {
@@ -1257,6 +1292,9 @@ static int checkout_branch(struct checkout_opts *opts,
 	    !new_branch_info->path)
 		die_expecting_a_branch(new_branch_info);
 
+	if (!opts->can_switch_when_in_progress)
+		die_if_some_operation_in_progress();
+
 	if (new_branch_info->path && !opts->force_detach && !opts->new_branch &&
 	    !opts->ignore_other_worktrees) {
 		int flag;
@@ -1514,6 +1552,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.only_merge_on_switching_branches = 0;
 	opts.accept_pathspec = 1;
 	opts.implicit_detach = 1;
+	opts.can_switch_when_in_progress = 1;
 
 	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
@@ -1549,6 +1588,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	opts.switch_branch_doing_nothing_is_ok = 0;
 	opts.only_merge_on_switching_branches = 1;
 	opts.implicit_detach = 0;
+	opts.can_switch_when_in_progress = 0;
 
 	options = parse_options_dup(switch_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From 1806c29f2eb5f7e4b5952f4fcc75f2afe279f1a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:16 +0700
Subject: switch: make --orphan switch to an empty tree
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Switching and creating branches always involves knowing the
<start-point> to begin the new branch from. Sometimes, people want to
create a new branch that does not have any commits yet; --orphan is a
flag to allow that.

--orphan overrides the default of HEAD for <start-point> instead causing
us to start from an empty history with all tracked files removed from
the index and working tree. The use of --orphan is incompatible with
specifying a <start-point>.

A note on the implementation. An alternative is just create a dummy
commit in-core with empty tree and switch to it. But there's a chance
the commit's SHA-1 may end up somewhere permanent like reflog. It's best
to make sure "commit" pointer is NULL to avoid it.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5f100c1..0351735 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -58,6 +58,7 @@ struct checkout_opts {
 	int switch_branch_doing_nothing_is_ok;
 	int only_merge_on_switching_branches;
 	int can_switch_when_in_progress;
+	int orphan_from_empty_tree;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -568,15 +569,21 @@ static int merge_working_tree(const struct checkout_opts *opts,
 {
 	int ret;
 	struct lock_file lock_file = LOCK_INIT;
+	struct tree *new_tree;
 
 	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 	if (read_cache_preload(NULL) < 0)
 		return error(_("index file corrupt"));
 
 	resolve_undo_clear();
+	if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
+		if (new_branch_info->commit)
+			BUG("'switch --orphan' should never accept a commit as starting point");
+		new_tree = parse_tree_indirect(the_hash_algo->empty_tree);
+	} else
+		new_tree = get_commit_tree(new_branch_info->commit);
 	if (opts->discard_changes) {
-		ret = reset_tree(get_commit_tree(new_branch_info->commit),
-				 opts, 1, writeout_error);
+		ret = reset_tree(new_tree, opts, 1, writeout_error);
 		if (ret)
 			return ret;
 	} else {
@@ -614,7 +621,8 @@ static int merge_working_tree(const struct checkout_opts *opts,
 					   &old_branch_info->commit->object.oid :
 					   the_hash_algo->empty_tree);
 		init_tree_desc(&trees[0], tree->buffer, tree->size);
-		tree = parse_tree_indirect(&new_branch_info->commit->object.oid);
+		parse_tree(new_tree);
+		tree = new_tree;
 		init_tree_desc(&trees[1], tree->buffer, tree->size);
 
 		ret = unpack_trees(2, trees, &topts);
@@ -663,7 +671,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 			o.verbosity = 0;
 			work = write_tree_from_memory(&o);
 
-			ret = reset_tree(get_commit_tree(new_branch_info->commit),
+			ret = reset_tree(new_tree,
 					 opts, 1,
 					 writeout_error);
 			if (ret)
@@ -672,13 +680,13 @@ static int merge_working_tree(const struct checkout_opts *opts,
 			o.branch1 = new_branch_info->name;
 			o.branch2 = "local";
 			ret = merge_trees(&o,
-					  get_commit_tree(new_branch_info->commit),
+					  new_tree,
 					  work,
 					  get_commit_tree(old_branch_info->commit),
 					  &result);
 			if (ret < 0)
 				exit(128);
-			ret = reset_tree(get_commit_tree(new_branch_info->commit),
+			ret = reset_tree(new_tree,
 					 opts, 0,
 					 writeout_error);
 			strbuf_release(&o.obuf);
@@ -696,7 +704,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
 
-	if (!opts->discard_changes && !opts->quiet)
+	if (!opts->discard_changes && !opts->quiet && new_branch_info->commit)
 		show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
 
 	return 0;
@@ -897,7 +905,10 @@ static void orphaned_commit_warning(struct commit *old_commit, struct commit *ne
 	add_pending_object(&revs, object, oid_to_hex(&object->oid));
 
 	for_each_ref(add_pending_uninteresting_ref, &revs);
-	add_pending_oid(&revs, "HEAD", &new_commit->object.oid, UNINTERESTING);
+	if (new_commit)
+		add_pending_oid(&revs, "HEAD",
+				&new_commit->object.oid,
+				UNINTERESTING);
 
 	if (prepare_revision_walk(&revs))
 		die(_("internal error in revision walk"));
@@ -932,6 +943,14 @@ static int switch_branches(const struct checkout_opts *opts,
 	if (old_branch_info.path)
 		skip_prefix(old_branch_info.path, "refs/heads/", &old_branch_info.name);
 
+	if (opts->new_orphan_branch && opts->orphan_from_empty_tree) {
+		if (new_branch_info->name)
+			BUG("'switch --orphan' should never accept a commit as starting point");
+		new_branch_info->commit = NULL;
+		new_branch_info->name = "(empty)";
+		do_merge = 1;
+	}
+
 	if (!new_branch_info->name) {
 		new_branch_info->name = "HEAD";
 		new_branch_info->commit = old_branch_info.commit;
@@ -1268,6 +1287,8 @@ static int checkout_branch(struct checkout_opts *opts,
 	if (opts->new_orphan_branch) {
 		if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 			die(_("'%s' cannot be used with '%s'"), "--orphan", "-t");
+		if (opts->orphan_from_empty_tree && new_branch_info->name)
+			die(_("'%s' cannot take <start-point>"), "--orphan");
 	} else if (opts->force_detach) {
 		if (opts->track != BRANCH_TRACK_UNSPECIFIED)
 			die(_("'%s' cannot be used with '%s'"), "--detach", "-t");
@@ -1553,6 +1574,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.accept_pathspec = 1;
 	opts.implicit_detach = 1;
 	opts.can_switch_when_in_progress = 1;
+	opts.orphan_from_empty_tree = 0;
 
 	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
@@ -1589,6 +1611,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	opts.only_merge_on_switching_branches = 1;
 	opts.implicit_detach = 0;
 	opts.can_switch_when_in_progress = 0;
+	opts.orphan_from_empty_tree = 1;
 
 	options = parse_options_dup(switch_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From c479ea36c011d3a1f90e1377b979425c10c46765 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:17 +0700
Subject: t: add tests for switch
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t2060-switch.sh b/t/t2060-switch.sh
new file mode 100755
index 0000000..f9efa29
--- /dev/null
+++ b/t/t2060-switch.sh
@@ -0,0 +1,96 @@
+#!/bin/sh
+
+test_description='switch basic functionality'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	test_commit first &&
+	git branch first-branch &&
+	test_commit second &&
+	test_commit third &&
+	git remote add origin nohost:/nopath &&
+	git update-ref refs/remotes/origin/foo first-branch
+'
+
+test_expect_success 'switch branch no arguments' '
+	test_must_fail git switch
+'
+
+test_expect_success 'switch branch' '
+	git switch first-branch &&
+	test_path_is_missing second.t
+'
+
+test_expect_success 'switch and detach' '
+	test_when_finished git switch master &&
+	test_must_fail git switch master^{commit} &&
+	git switch --detach master^{commit} &&
+	test_must_fail git symbolic-ref HEAD
+'
+
+test_expect_success 'switch and detach current branch' '
+	test_when_finished git switch master &&
+	git switch master &&
+	git switch --detach &&
+	test_must_fail git symbolic-ref HEAD
+'
+
+test_expect_success 'switch and create branch' '
+	test_when_finished git switch master &&
+	git switch -c temp master^ &&
+	test_cmp_rev master^ refs/heads/temp &&
+	echo refs/heads/temp >expected-branch &&
+	git symbolic-ref HEAD >actual-branch &&
+	test_cmp expected-branch actual-branch
+'
+
+test_expect_success 'force create branch from HEAD' '
+	test_when_finished git switch master &&
+	git switch --detach master &&
+	test_must_fail git switch -c temp &&
+	git switch -C temp &&
+	test_cmp_rev master refs/heads/temp &&
+	echo refs/heads/temp >expected-branch &&
+	git symbolic-ref HEAD >actual-branch &&
+	test_cmp expected-branch actual-branch
+'
+
+test_expect_success 'new orphan branch from empty' '
+	test_when_finished git switch master &&
+	test_must_fail git switch --orphan new-orphan HEAD &&
+	git switch --orphan new-orphan &&
+	test_commit orphan &&
+	git cat-file commit refs/heads/new-orphan >commit &&
+	! grep ^parent commit &&
+	git ls-files >tracked-files &&
+	echo orphan.t >expected &&
+	test_cmp expected tracked-files
+'
+
+test_expect_success 'switching ignores file of same branch name' '
+	test_when_finished git switch master &&
+	: >first-branch &&
+	git switch first-branch &&
+	echo refs/heads/first-branch >expected &&
+	git symbolic-ref HEAD >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'guess and create branch ' '
+	test_when_finished git switch master &&
+	test_must_fail git switch --no-guess foo &&
+	git switch foo &&
+	echo refs/heads/foo >expected &&
+	git symbolic-ref HEAD >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'not switching when something is in progress' '
+	test_when_finished rm -f .git/MERGE_HEAD &&
+	# fake a merge-in-progress
+	cp .git/HEAD .git/MERGE_HEAD &&
+	test_must_fail git switch -d @^
+'
+
+test_done
-- 
cgit v0.10.2-6-g49f6


From ae36fe694180ad2646983d43c5bf12841ac2db47 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:18 +0700
Subject: completion: support switch
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Completion support for --guess could be made better. If no --detach is
given, we should only provide a list of refs/heads/* and dwim ones,
not the entire ref space. But I still can't penetrate that
__git_refs() function yet.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 976e4a6..b24bc48 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -37,7 +37,8 @@
 #   GIT_COMPLETION_CHECKOUT_NO_GUESS
 #
 #     When set to "1", do not include "DWIM" suggestions in git-checkout
-#     completion (e.g., completing "foo" when "origin/foo" exists).
+#     and git-switch completion (e.g., completing "foo" when "origin/foo"
+#     exists).
 
 case "$COMP_WORDBREAKS" in
 *:*) : great ;;
@@ -2158,6 +2159,40 @@ _git_status ()
 	__git_complete_index_file "$complete_opt"
 }
 
+_git_switch ()
+{
+	case "$cur" in
+	--conflict=*)
+		__gitcomp "diff3 merge" "" "${cur##--conflict=}"
+		;;
+	--*)
+		__gitcomp_builtin switch
+		;;
+	*)
+		# check if --track, --no-track, or --no-guess was specified
+		# if so, disable DWIM mode
+		local track_opt="--track" only_local_ref=n
+		if [ "$GIT_COMPLETION_CHECKOUT_NO_GUESS" = "1" ] ||
+		   [ -n "$(__git_find_on_cmdline "--track --no-track --no-guess")" ]; then
+			track_opt=''
+		fi
+		# explicit --guess enables DWIM mode regardless of
+		# $GIT_COMPLETION_CHECKOUT_NO_GUESS
+		if [ -n "$(__git_find_on_cmdline "--guess")" ]; then
+			track_opt='--track'
+		fi
+		if [ -z "$(__git_find_on_cmdline "-d --detach")" ]; then
+			only_local_ref=y
+		fi
+		if [ $only_local_ref = y -a -z "$track_opt" ]; then
+			__gitcomp_direct "$(__git_heads "" "$cur" " ")"
+		else
+			__git_complete_refs $track_opt
+		fi
+		;;
+	esac
+}
+
 __git_config_get_set_variables ()
 {
 	local prevword word config_file= c=$cword
-- 
cgit v0.10.2-6-g49f6


From 328c6cb853d7237098569de9f94bc3d259846a08 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Fri, 29 Mar 2019 17:39:19 +0700
Subject: doc: promote "git switch"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The new command "git switch" is added to avoid the confusion of
one-command-do-all "git checkout" for new users. They are also helpful
to avoid ambiguation context.

For these reasons, promote it everywhere possible. This includes
documentation, suggestions/advice from other commands...

The "Checking out files" progress line in unpack-trees.c is also updated
to "Updating files" to be neutral to both git-checkout and git-switch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index 0cd87dd..1e2d89b 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -48,7 +48,7 @@ The command's second form creates a new branch head named <branchname>
 which points to the current `HEAD`, or <start-point> if given.
 
 Note that this will create the new branch, but it will not switch the
-working tree to it; use "git checkout <newbranch>" to switch to the
+working tree to it; use "git switch <newbranch>" to switch to the
 new branch.
 
 When a local branch is started off a remote-tracking branch, Git sets up the
@@ -198,7 +198,7 @@ This option is only applicable in non-verbose mode.
 +
 This behavior is the default when the start point is a remote-tracking branch.
 Set the branch.autoSetupMerge configuration variable to `false` if you
-want `git checkout` and `git branch` to always behave as if `--no-track`
+want `git switch`, `git checkout` and `git branch` to always behave as if `--no-track`
 were given. Set it to `always` if you want this behavior when the
 start-point is either a local or remote-tracking branch.
 
@@ -297,7 +297,7 @@ Start development from a known tag::
 $ git clone git://git.kernel.org/pub/scm/.../linux-2.6 my2.6
 $ cd my2.6
 $ git branch my2.6.14 v2.6.14   <1>
-$ git checkout my2.6.14
+$ git switch my2.6.14
 ------------
 +
 <1> This step and the next one could be combined into a single step with
@@ -322,9 +322,9 @@ $ git branch -D test                                    <2>
 NOTES
 -----
 
-If you are creating a branch that you want to checkout immediately, it is
-easier to use the git checkout command with its `-b` option to create
-a branch and check it out with a single command.
+If you are creating a branch that you want to switch to immediately,
+it is easier to use the "git switch" command with its `-c` option to
+do the same thing with a single command.
 
 The options `--contains`, `--no-contains`, `--merged` and `--no-merged`
 serve four related but different purposes:
diff --git a/Documentation/git-check-ref-format.txt b/Documentation/git-check-ref-format.txt
index d9de992..ee6a414 100644
--- a/Documentation/git-check-ref-format.txt
+++ b/Documentation/git-check-ref-format.txt
@@ -88,7 +88,8 @@ but it is explicitly forbidden at the beginning of a branch name).
 When run with `--branch` option in a repository, the input is first
 expanded for the ``previous checkout syntax''
 `@{-n}`.  For example, `@{-1}` is a way to refer the last thing that
-was checked out using "git checkout" operation. This option should be
+was checked out using "git switch" or "git checkout" operation.
+This option should be
 used by porcelains to accept this syntax anywhere a branch name is
 expected, so they can act as if you typed the branch name. As an
 exception note that, the ``previous checkout operation'' might result
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 1af85d4..0a24a56 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -421,7 +421,7 @@ One way to test if your MUA is set up correctly is:
 * Apply it:
 
     $ git fetch <project> master:test-apply
-    $ git checkout test-apply
+    $ git switch test-apply
     $ git reset --hard
     $ git am a.patch
 
diff --git a/Documentation/git-merge-base.txt b/Documentation/git-merge-base.txt
index 9f07f4f..261d5c1 100644
--- a/Documentation/git-merge-base.txt
+++ b/Documentation/git-merge-base.txt
@@ -149,7 +149,7 @@ instead.
 Discussion on fork-point mode
 -----------------------------
 
-After working on the `topic` branch created with `git checkout -b
+After working on the `topic` branch created with `git switch -c
 topic origin/master`, the history of remote-tracking branch
 `origin/master` may have been rewound and rebuilt, leading to a
 history of this shape:
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 6363d67..c742b73 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -17,7 +17,7 @@ SYNOPSIS
 DESCRIPTION
 -----------
 If <branch> is specified, 'git rebase' will perform an automatic
-`git checkout <branch>` before doing anything else.  Otherwise
+`git switch <branch>` before doing anything else.  Otherwise
 it remains on the current branch.
 
 If <upstream> is not specified, the upstream configured in
diff --git a/Documentation/git-remote.txt b/Documentation/git-remote.txt
index 0cad37f..9659abb 100644
--- a/Documentation/git-remote.txt
+++ b/Documentation/git-remote.txt
@@ -230,7 +230,7 @@ $ git branch -r
   staging/master
   staging/staging-linus
   staging/staging-next
-$ git checkout -b staging staging/master
+$ git switch -c staging staging/master
 ...
 ------------
 
diff --git a/Documentation/git-rerere.txt b/Documentation/git-rerere.txt
index df310d2..fe4434a 100644
--- a/Documentation/git-rerere.txt
+++ b/Documentation/git-rerere.txt
@@ -91,7 +91,7 @@ For such a test, you need to merge master and topic somehow.
 One way to do it is to pull master into the topic branch:
 
 ------------
-	$ git checkout topic
+	$ git switch topic
 	$ git merge master
 
               o---*---o---+ topic
@@ -113,10 +113,10 @@ the upstream might have been advanced since the test merge `+`,
 in which case the final commit graph would look like this:
 
 ------------
-	$ git checkout topic
+	$ git switch topic
 	$ git merge master
 	$ ... work on both topic and master branches
-	$ git checkout master
+	$ git switch master
 	$ git merge topic
 
               o---*---o---+---o---o topic
@@ -136,11 +136,11 @@ merges, you could blow away the test merge, and keep building on
 top of the tip before the test merge:
 
 ------------
-	$ git checkout topic
+	$ git switch topic
 	$ git merge master
 	$ git reset --hard HEAD^ ;# rewind the test merge
 	$ ... work on both topic and master branches
-	$ git checkout master
+	$ git switch master
 	$ git merge topic
 
               o---*---o-------o---o topic
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index 132f8e5..cbf901e 100644
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -149,9 +149,9 @@ See also the `--amend` option to linkgit:git-commit[1].
 Undo a commit, making it a topic branch::
 +
 ------------
-$ git branch topic/wip     <1>
-$ git reset --hard HEAD~3  <2>
-$ git checkout topic/wip   <3>
+$ git branch topic/wip          <1>
+$ git reset --hard HEAD~3       <2>
+$ git switch topic/wip          <3>
 ------------
 +
 <1> You have made some commits, but realize they were premature
@@ -232,13 +232,13 @@ working tree are not in any shape to be committed yet, but you
 need to get to the other branch for a quick bugfix.
 +
 ------------
-$ git checkout feature ;# you were working in "feature" branch and
-$ work work work       ;# got interrupted
+$ git switch feature  ;# you were working in "feature" branch and
+$ work work work      ;# got interrupted
 $ git commit -a -m "snapshot WIP"                 <1>
-$ git checkout master
+$ git switch master
 $ fix fix fix
 $ git commit ;# commit with real log
-$ git checkout feature
+$ git switch feature
 $ git reset --soft HEAD^ ;# go back to WIP state  <2>
 $ git reset                                       <3>
 ------------
@@ -279,18 +279,18 @@ reset it while keeping the changes in your working tree.
 +
 ------------
 $ git tag start
-$ git checkout -b branch1
+$ git switch -c branch1
 $ edit
 $ git commit ...                            <1>
 $ edit
-$ git checkout -b branch2                   <2>
+$ git switch -c branch2                     <2>
 $ git reset --keep start                    <3>
 ------------
 +
 <1> This commits your first edits in `branch1`.
 <2> In the ideal world, you could have realized that the earlier
     commit did not belong to the new topic when you created and switched
-    to `branch2` (i.e. `git checkout -b branch2 start`), but nobody is
+    to `branch2` (i.e. `git switch -c branch2 start`), but nobody is
     perfect.
 <3> But you can use `reset --keep` to remove the unwanted commit after
     you switched to `branch2`.
diff --git a/Documentation/git-stash.txt b/Documentation/git-stash.txt
index 7ef8c47..ebb6282 100644
--- a/Documentation/git-stash.txt
+++ b/Documentation/git-stash.txt
@@ -235,12 +235,12 @@ return to your original branch to make the emergency fix, like this:
 +
 ----------------------------------------------------------------
 # ... hack hack hack ...
-$ git checkout -b my_wip
+$ git switch -c my_wip
 $ git commit -a -m "WIP"
-$ git checkout master
+$ git switch master
 $ edit emergency fix
 $ git commit -a -m "Fix in a hurry"
-$ git checkout my_wip
+$ git switch my_wip
 $ git reset --soft HEAD^
 # ... continue hacking ...
 ----------------------------------------------------------------
@@ -293,7 +293,8 @@ SEE ALSO
 linkgit:git-checkout[1],
 linkgit:git-commit[1],
 linkgit:git-reflog[1],
-linkgit:git-reset[1]
+linkgit:git-reset[1],
+linkgit:git-switch[1]
 
 GIT
 ---
diff --git a/Documentation/gitcore-tutorial.txt b/Documentation/gitcore-tutorial.txt
index e29a9ef..f880d21 100644
--- a/Documentation/gitcore-tutorial.txt
+++ b/Documentation/gitcore-tutorial.txt
@@ -741,7 +741,7 @@ used earlier, and create a branch in it. You do that by simply just
 saying that you want to check out a new branch:
 
 ------------
-$ git checkout -b mybranch
+$ git switch -c mybranch
 ------------
 
 will create a new branch based at the current `HEAD` position, and switch
@@ -755,7 +755,7 @@ just telling 'git checkout' what the base of the checkout would be.
 In other words, if you have an earlier tag or branch, you'd just do
 
 ------------
-$ git checkout -b mybranch earlier-commit
+$ git switch -c mybranch earlier-commit
 ------------
 
 and it would create the new branch `mybranch` at the earlier commit,
@@ -765,7 +765,7 @@ and check out the state at that time.
 You can always just jump back to your original `master` branch by doing
 
 ------------
-$ git checkout master
+$ git switch master
 ------------
 
 (or any other branch-name, for that matter) and if you forget which
@@ -794,7 +794,7 @@ $ git branch <branchname> [startingpoint]
 
 which will simply _create_ the branch, but will not do anything further.
 You can then later -- once you decide that you want to actually develop
-on that branch -- switch to that branch with a regular 'git checkout'
+on that branch -- switch to that branch with a regular 'git switch'
 with the branchname as the argument.
 
 
@@ -808,7 +808,7 @@ being the same as the original `master` branch, let's make sure we're in
 that branch, and do some work there.
 
 ------------------------------------------------
-$ git checkout mybranch
+$ git switch mybranch
 $ echo "Work, work, work" >>hello
 $ git commit -m "Some work." -i hello
 ------------------------------------------------
@@ -825,7 +825,7 @@ does some work in the original branch, and simulate that by going back
 to the master branch, and editing the same file differently there:
 
 ------------
-$ git checkout master
+$ git switch master
 ------------
 
 Here, take a moment to look at the contents of `hello`, and notice how they
@@ -958,7 +958,7 @@ to the `master` branch. Let's go back to `mybranch`, and run
 'git merge' to get the "upstream changes" back to your branch.
 
 ------------
-$ git checkout mybranch
+$ git switch mybranch
 $ git merge -m "Merge upstream changes." master
 ------------
 
@@ -1133,9 +1133,8 @@ Remember, before running 'git merge', our `master` head was at
 work." commit.
 
 ------------
-$ git checkout mybranch
-$ git reset --hard master^2
-$ git checkout master
+$ git switch -C mybranch master^2
+$ git switch master
 $ git reset --hard master^
 ------------
 
diff --git a/Documentation/giteveryday.txt b/Documentation/giteveryday.txt
index 9f2528f..ad455f3 100644
--- a/Documentation/giteveryday.txt
+++ b/Documentation/giteveryday.txt
@@ -41,7 +41,7 @@ following commands.
 
   * linkgit:git-log[1] to see what happened.
 
-  * linkgit:git-checkout[1] and linkgit:git-branch[1] to switch
+  * linkgit:git-switch[1] and linkgit:git-branch[1] to switch
     branches.
 
   * linkgit:git-add[1] to manage the index file.
@@ -80,7 +80,7 @@ $ git tag v2.43 <2>
 Create a topic branch and develop.::
 +
 ------------
-$ git checkout -b alsa-audio <1>
+$ git switch -c alsa-audio <1>
 $ edit/compile/test
 $ git checkout -- curses/ux_audio_oss.c <2>
 $ git add curses/ux_audio_alsa.c <3>
@@ -90,7 +90,7 @@ $ git commit -a -s <5>
 $ edit/compile/test
 $ git diff HEAD^ <6>
 $ git commit -a --amend <7>
-$ git checkout master <8>
+$ git switch master <8>
 $ git merge alsa-audio <9>
 $ git log --since='3 days ago' <10>
 $ git log v2.43.. curses/ <11>
@@ -148,11 +148,11 @@ Clone the upstream and work on it.  Feed changes to upstream.::
 ------------
 $ git clone git://git.kernel.org/pub/scm/.../torvalds/linux-2.6 my2.6
 $ cd my2.6
-$ git checkout -b mine master <1>
+$ git switch -c mine master <1>
 $ edit/compile/test; git commit -a -s <2>
 $ git format-patch master <3>
 $ git send-email --to="person <email@example.com>" 00*.patch <4>
-$ git checkout master <5>
+$ git switch master <5>
 $ git pull <6>
 $ git log -p ORIG_HEAD.. arch/i386 include/asm-i386 <7>
 $ git ls-remote --heads http://git.kernel.org/.../jgarzik/libata-dev.git <8>
@@ -194,7 +194,7 @@ satellite$ edit/compile/test/commit
 satellite$ git push origin <4>
 
 mothership$ cd frotz
-mothership$ git checkout master
+mothership$ git switch master
 mothership$ git merge satellite/master <5>
 ------------
 +
@@ -216,7 +216,7 @@ machine into the master branch.
 Branch off of a specific tag.::
 +
 ------------
-$ git checkout -b private2.6.14 v2.6.14 <1>
+$ git switch -c private2.6.14 v2.6.14 <1>
 $ edit/compile/test; git commit -a
 $ git checkout master
 $ git cherry-pick v2.6.14..private2.6.14 <2>
@@ -274,14 +274,14 @@ $ mailx <3>
 & s 2 3 4 5 ./+to-apply
 & s 7 8 ./+hold-linus
 & q
-$ git checkout -b topic/one master
+$ git switch -c topic/one master
 $ git am -3 -i -s ./+to-apply <4>
 $ compile/test
-$ git checkout -b hold/linus && git am -3 -i -s ./+hold-linus <5>
-$ git checkout topic/one && git rebase master <6>
-$ git checkout pu && git reset --hard next <7>
+$ git switch -c hold/linus && git am -3 -i -s ./+hold-linus <5>
+$ git switch topic/one && git rebase master <6>
+$ git switch -C pu next <7>
 $ git merge topic/one topic/two && git merge hold/linus <8>
-$ git checkout maint
+$ git switch maint
 $ git cherry-pick master~4 <9>
 $ compile/test
 $ git tag -s -m "GIT 0.99.9x" v0.99.9x <10>
diff --git a/Documentation/gittutorial.txt b/Documentation/gittutorial.txt
index 242de31..e6ad6b5 100644
--- a/Documentation/gittutorial.txt
+++ b/Documentation/gittutorial.txt
@@ -207,7 +207,7 @@ automatically.  The asterisk marks the branch you are currently on;
 type
 
 ------------------------------------------------
-$ git checkout experimental
+$ git switch experimental
 ------------------------------------------------
 
 to switch to the experimental branch.  Now edit a file, commit the
@@ -216,7 +216,7 @@ change, and switch back to the master branch:
 ------------------------------------------------
 (edit file)
 $ git commit -a
-$ git checkout master
+$ git switch master
 ------------------------------------------------
 
 Check that the change you made is no longer visible, since it was
diff --git a/Documentation/gitworkflows.txt b/Documentation/gitworkflows.txt
index ca11c7b..abc0dc6 100644
--- a/Documentation/gitworkflows.txt
+++ b/Documentation/gitworkflows.txt
@@ -301,8 +301,7 @@ topics on 'next':
 .Rewind and rebuild next
 [caption="Recipe: "]
 =====================================
-* `git checkout next`
-* `git reset --hard master`
+* `git switch -C next master`
 * `git merge ai/topic_in_next1`
 * `git merge ai/topic_in_next2`
 * ...
diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt
index 72daa20..a1c7a65 100644
--- a/Documentation/revisions.txt
+++ b/Documentation/revisions.txt
@@ -115,7 +115,7 @@ Here's an example to make it more clear:
 ------------------------------
 $ git config push.default current
 $ git config remote.pushdefault myfork
-$ git checkout -b mybranch origin/master
+$ git switch -c mybranch origin/master
 
 $ git rev-parse --symbolic-full-name @{upstream}
 refs/remotes/origin/master
diff --git a/Documentation/user-manual.txt b/Documentation/user-manual.txt
index eff7890..94799fa 100644
--- a/Documentation/user-manual.txt
+++ b/Documentation/user-manual.txt
@@ -122,10 +122,10 @@ Tags are expected to always point at the same version of a project,
 while heads are expected to advance as development progresses.
 
 Create a new branch head pointing to one of these versions and check it
-out using linkgit:git-checkout[1]:
+out using linkgit:git-switch[1]:
 
 ------------------------------------------------
-$ git checkout -b new v2.6.13
+$ git switch -c new v2.6.13
 ------------------------------------------------
 
 The working directory then reflects the contents that the project had
@@ -282,10 +282,10 @@ a summary of the commands:
 	this command will fail with a warning.
 `git branch -D <branch>`::
 	delete the branch `<branch>` irrespective of its merged status.
-`git checkout <branch>`::
+`git switch <branch>`::
 	make the current branch `<branch>`, updating the working
 	directory to reflect the version referenced by `<branch>`.
-`git checkout -b <new> <start-point>`::
+`git switch -c <new> <start-point>`::
 	create a new branch `<new>` referencing `<start-point>`, and
 	check it out.
 
@@ -302,22 +302,22 @@ ref: refs/heads/master
 Examining an old version without creating a new branch
 ------------------------------------------------------
 
-The `git checkout` command normally expects a branch head, but will also
-accept an arbitrary commit; for example, you can check out the commit
-referenced by a tag:
+The `git switch` command normally expects a branch head, but will also
+accept an arbitrary commit when invoked with --detach; for example,
+you can check out the commit referenced by a tag:
 
 ------------------------------------------------
-$ git checkout v2.6.17
+$ git switch --detach v2.6.17
 Note: checking out 'v2.6.17'.
 
 You are in 'detached HEAD' state. You can look around, make experimental
 changes and commit them, and you can discard any commits you make in this
-state without impacting any branches by performing another checkout.
+state without impacting any branches by performing another switch.
 
 If you want to create a new branch to retain commits you create, you may
-do so (now or later) by using -b with the checkout command again. Example:
+do so (now or later) by using -c with the switch command again. Example:
 
-  git checkout -b new_branch_name
+  git switch -c new_branch_name
 
 HEAD is now at 427abfa Linux v2.6.17
 ------------------------------------------------
@@ -373,7 +373,7 @@ You might want to build on one of these remote-tracking branches
 on a branch of your own, just as you would for a tag:
 
 ------------------------------------------------
-$ git checkout -b my-todo-copy origin/todo
+$ git switch -c my-todo-copy origin/todo
 ------------------------------------------------
 
 You can also check out `origin/todo` directly to examine it or
@@ -2211,8 +2211,8 @@ $ git branch --track release origin/master
 These can be easily kept up to date using linkgit:git-pull[1].
 
 -------------------------------------------------
-$ git checkout test && git pull
-$ git checkout release && git pull
+$ git switch test && git pull
+$ git switch release && git pull
 -------------------------------------------------
 
 Important note!  If you have any local changes in these branches, then
@@ -2264,7 +2264,7 @@ tested changes
 2) help future bug hunters that use `git bisect` to find problems
 
 -------------------------------------------------
-$ git checkout -b speed-up-spinlocks v2.6.35
+$ git switch -c speed-up-spinlocks v2.6.35
 -------------------------------------------------
 
 Now you apply the patch(es), run some tests, and commit the change(s).  If
@@ -2279,7 +2279,7 @@ When you are happy with the state of this change, you can merge it into the
 "test" branch in preparation to make it public:
 
 -------------------------------------------------
-$ git checkout test && git merge speed-up-spinlocks
+$ git switch test && git merge speed-up-spinlocks
 -------------------------------------------------
 
 It is unlikely that you would have any conflicts here ... but you might if you
@@ -2291,7 +2291,7 @@ see the value of keeping each patch (or patch series) in its own branch.  It
 means that the patches can be moved into the `release` tree in any order.
 
 -------------------------------------------------
-$ git checkout release && git merge speed-up-spinlocks
+$ git switch release && git merge speed-up-spinlocks
 -------------------------------------------------
 
 After a while, you will have a number of branches, and despite the
@@ -2512,7 +2512,7 @@ Suppose that you create a branch `mywork` on a remote-tracking branch
 `origin`, and create some commits on top of it:
 
 -------------------------------------------------
-$ git checkout -b mywork origin
+$ git switch -c mywork origin
 $ vi file.txt
 $ git commit
 $ vi otherfile.txt
@@ -2552,7 +2552,7 @@ commits without any merges, you may instead choose to use
 linkgit:git-rebase[1]:
 
 -------------------------------------------------
-$ git checkout mywork
+$ git switch mywork
 $ git rebase origin
 -------------------------------------------------
 
@@ -3668,13 +3668,13 @@ change within the submodule, and then update the superproject to reference the
 new commit:
 
 -------------------------------------------------
-$ git checkout master
+$ git switch master
 -------------------------------------------------
 
 or
 
 -------------------------------------------------
-$ git checkout -b fix-up
+$ git switch -c fix-up
 -------------------------------------------------
 
 then
@@ -4194,7 +4194,7 @@ start.
 A good place to start is with the contents of the initial commit, with:
 
 ----------------------------------------------------
-$ git checkout e83c5163
+$ git switch --detach e83c5163
 ----------------------------------------------------
 
 The initial revision lays the foundation for almost everything Git has
@@ -4437,10 +4437,10 @@ Managing branches
 -----------------
 
 -----------------------------------------------
-$ git branch	     # list all local branches in this repo
-$ git checkout test  # switch working directory to branch "test"
-$ git branch new     # create branch "new" starting at current HEAD
-$ git branch -d new  # delete branch "new"
+$ git branch			# list all local branches in this repo
+$ git switch test	        # switch working directory to branch "test"
+$ git branch new		# create branch "new" starting at current HEAD
+$ git branch -d new		# delete branch "new"
 -----------------------------------------------
 
 Instead of basing a new branch on current HEAD (the default), use:
@@ -4456,7 +4456,7 @@ $ git branch new test~10 # ten commits before tip of branch "test"
 Create and switch to a new branch at the same time:
 
 -----------------------------------------------
-$ git checkout -b new v2.6.15
+$ git switch -c new v2.6.15
 -----------------------------------------------
 
 Update and examine branches from the repository you cloned from:
@@ -4467,7 +4467,7 @@ $ git branch -r		# list
   origin/master
   origin/next
   ...
-$ git checkout -b masterwork origin/master
+$ git switch -c masterwork origin/master
 -----------------------------------------------
 
 Fetch a branch from a different repository, and give it a new
diff --git a/advice.c b/advice.c
index b224825..24a7741 100644
--- a/advice.c
+++ b/advice.c
@@ -191,20 +191,20 @@ void NORETURN die_conclude_merge(void)
 void detach_advice(const char *new_name)
 {
 	const char *fmt =
-	_("Note: checking out '%s'.\n"
+	_("Note: switching to '%s'.\n"
 	"\n"
 	"You are in 'detached HEAD' state. You can look around, make experimental\n"
 	"changes and commit them, and you can discard any commits you make in this\n"
-	"state without impacting any branches by performing another checkout.\n"
+	"state without impacting any branches by switching back to a branch.\n"
 	"\n"
 	"If you want to create a new branch to retain commits you create, you may\n"
-	"do so (now or later) by using -b with the checkout command again. Example:\n"
+	"do so (now or later) by using -c with the switch command. Example:\n"
 	"\n"
-	"  git checkout -b <new-branch-name>\n"
+	"  git switch -c <new-branch-name>\n"
 	"\n"
-	"Or undo this checkout with:\n"
+	"Or undo this operation with:\n"
 	"\n"
-	"  git checkout -\n"
+	"  git switch -\n"
 	"\n"
 	"Turn off this advice by setting config variable advice.detachedHead to false\n\n");
 
diff --git a/sha1-name.c b/sha1-name.c
index 6dda2c1..da0518c 100644
--- a/sha1-name.c
+++ b/sha1-name.c
@@ -743,7 +743,7 @@ static int get_oid_basic(const char *str, int len, struct object_id *oid,
 	"because it will be ignored when you just specify 40-hex. These refs\n"
 	"may be created by mistake. For example,\n"
 	"\n"
-	"  git checkout -b $br $(git rev-parse ...)\n"
+	"  git switch -c $br $(git rev-parse ...)\n"
 	"\n"
 	"where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
 	"examine these refs and maybe delete them. Turn this message off by\n"
diff --git a/t/t2020-checkout-detach.sh b/t/t2020-checkout-detach.sh
index 743c724..b748db9 100755
--- a/t/t2020-checkout-detach.sh
+++ b/t/t2020-checkout-detach.sh
@@ -195,20 +195,20 @@ test_expect_success 'describe_detached_head prints no SHA-1 ellipsis when not as
 
 	# The first detach operation is more chatty than the following ones.
 	cat >1st_detach <<-EOF &&
-	Note: checking out 'HEAD^'.
+	Note: switching to 'HEAD^'.
 
 	You are in 'detached HEAD' state. You can look around, make experimental
 	changes and commit them, and you can discard any commits you make in this
-	state without impacting any branches by performing another checkout.
+	state without impacting any branches by switching back to a branch.
 
 	If you want to create a new branch to retain commits you create, you may
-	do so (now or later) by using -b with the checkout command again. Example:
+	do so (now or later) by using -c with the switch command. Example:
 
-	  git checkout -b <new-branch-name>
+	  git switch -c <new-branch-name>
 
-	Or undo this checkout with:
+	Or undo this operation with:
 
-	  git checkout -
+	  git switch -
 
 	Turn off this advice by setting config variable advice.detachedHead to false
 
@@ -277,20 +277,20 @@ test_expect_success 'describe_detached_head does print SHA-1 ellipsis when asked
 
 	# The first detach operation is more chatty than the following ones.
 	cat >1st_detach <<-EOF &&
-	Note: checking out 'HEAD^'.
+	Note: switching to 'HEAD^'.
 
 	You are in 'detached HEAD' state. You can look around, make experimental
 	changes and commit them, and you can discard any commits you make in this
-	state without impacting any branches by performing another checkout.
+	state without impacting any branches by switching back to a branch.
 
 	If you want to create a new branch to retain commits you create, you may
-	do so (now or later) by using -b with the checkout command again. Example:
+	do so (now or later) by using -c with the switch command. Example:
 
-	  git checkout -b <new-branch-name>
+	  git switch -c <new-branch-name>
 
-	Or undo this checkout with:
+	Or undo this operation with:
 
-	  git checkout -
+	  git switch -
 
 	Turn off this advice by setting config variable advice.detachedHead to false
 
diff --git a/unpack-trees.c b/unpack-trees.c
index 22c41a3..5ff64a9 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -313,7 +313,7 @@ static struct progress *get_progress(struct unpack_trees_options *o)
 			total++;
 	}
 
-	return start_delayed_progress(_("Checking out files"), total);
+	return start_delayed_progress(_("Updating files"), total);
 }
 
 static void setup_collided_checkout_detection(struct checkout *state,
-- 
cgit v0.10.2-6-g49f6


From 46e91b663badd99b3807ab34decfd32f3cbf15e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:45 +0700
Subject: checkout: split part of it to new command 'restore'
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Previously the switching branch business of 'git checkout' becomes a
new command 'switch'. This adds the restore command for the checking
out paths path.

Similar to git-switch, a new man page is added to describe what the
command will become. The implementation will be updated shortly to
match the man page.

A couple main differences from 'git checkout <paths>':

- 'restore' by default will only update worktree. This matters more
  when --source is specified ('checkout <tree> <paths>' updates both
  worktree and index).

- 'restore --staged' can be used to restore the index. This command
  overlaps with 'git reset <paths>'.

- both worktree and index could also be restored at the same time
  (from a tree) when both --staged and --worktree are specified. This
  overlaps with 'git checkout <tree> <paths>'

- default source for restoring worktree and index is the index and
  HEAD respectively. A different (tree) source could be specified as
  with --source (*).

- when both index and worktree are restored, --source must be
  specified since the default source for these two individual targets
  are different (**)

- --no-overlay is enabled by default, if an entry is missing in the
  source, restoring means deleting the entry

(*) I originally went with --from instead of --source. I still think
  --from is a better name. The short option -f however is already
  taken by force. And I do think short option is good to have, e.g. to
  write -s@ or -s@^ instead of --source=HEAD.

(**) If you sit down and think about it, moving worktree's source from
  the index to HEAD makes sense, but nobody is really thinking it
  through when they type the commands.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/.gitignore b/.gitignore
index c687b92..fb37710 100644
--- a/.gitignore
+++ b/.gitignore
@@ -143,6 +143,7 @@
 /git-request-pull
 /git-rerere
 /git-reset
+/git-restore
 /git-rev-list
 /git-rev-parse
 /git-revert
diff --git a/Documentation/config/interactive.txt b/Documentation/config/interactive.txt
index ad846dd..a2d3c7e 100644
--- a/Documentation/config/interactive.txt
+++ b/Documentation/config/interactive.txt
@@ -2,7 +2,8 @@ interactive.singleKey::
 	In interactive commands, allow the user to provide one-letter
 	input with a single key (i.e., without hitting enter).
 	Currently this is used by the `--patch` mode of
-	linkgit:git-add[1], linkgit:git-checkout[1], linkgit:git-commit[1],
+	linkgit:git-add[1], linkgit:git-checkout[1],
+	linkgit:git-restore[1], linkgit:git-commit[1],
 	linkgit:git-reset[1], and linkgit:git-stash[1]. Note that this
 	setting is silently ignored if portable keystroke input
 	is not available; requires the Perl module Term::ReadKey.
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 58f18a0..a294652 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -570,7 +570,8 @@ $ git add frotz
 
 SEE ALSO
 --------
-linkgit:git-switch[1]
+linkgit:git-switch[1],
+linkgit:git-restore[1]
 
 GIT
 ---
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index cbf901e..c25f8a9 100644
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -25,7 +25,8 @@ The `<tree-ish>`/`<commit>` defaults to `HEAD` in all forms.
 	the current branch.)
 +
 This means that `git reset <paths>` is the opposite of `git add
-<paths>`.
+<paths>`. This command is equivalent to
+`git restore [--source=<tree-ish>] --staged <paths>...`.
 +
 After running `git reset <paths>` to update the index entry, you can
 use linkgit:git-checkout[1] to check the contents out of the index to
@@ -86,8 +87,8 @@ but carries forward unmerged index entries.
 	changes, reset is aborted.
 --
 
-If you want to undo a commit other than the latest on a branch,
-linkgit:git-revert[1] is your friend.
+See "Reset, restore and revert" in linkgit:git[1] for the differences
+between the three commands.
 
 
 OPTIONS
diff --git a/Documentation/git-restore.txt b/Documentation/git-restore.txt
new file mode 100644
index 0000000..b608f3f
--- /dev/null
+++ b/Documentation/git-restore.txt
@@ -0,0 +1,183 @@
+git-restore(1)
+==============
+
+NAME
+----
+git-restore - Restore working tree files
+
+SYNOPSIS
+--------
+[verse]
+'git restore' [<options>] [--source=<tree>] [--staged] [--worktree] <pathspec>...
+'git restore' (-p|--patch) [<options>] [--source=<tree>] [--staged] [--worktree] [<pathspec>...]
+
+DESCRIPTION
+-----------
+Restore specified paths in the working tree with some contents from a
+restore source. If a path is tracked but does not exist in the restore
+source, it will be removed to match the source.
+
+The command can also be used to restore the content in the index with
+`--staged`, or restore both the working tree and the index with
+`--staged --worktree`.
+
+By default, the restore sources for working tree and the index are the
+index and `HEAD` respectively. `--source` could be used to specify a
+commit as the restore source.
+
+See "Reset, restore and revert" in linkgit:git[1] for the differences
+between the three commands.
+
+OPTIONS
+-------
+-s <tree>::
+--source=<tree>::
+	Restore the working tree files with the content from the given
+	tree. It is common to specify the source tree by naming a
+	commit, branch or tag associated with it.
++
+If not specified, the default restore source for the working tree is
+the index, and the default restore source for the index index is
+`HEAD`. When both `--staged` and `--worktree` are specified,
+`--source` must also be specified.
+
+-p::
+--patch::
+	Interactively select hunks in the difference between the
+	restore source and the restore location. See the ``Interactive
+	Mode'' section of linkgit:git-add[1] to learn how to operate
+	the `--patch` mode.
++
+Note that `--patch` can accept no pathspec and will prompt to restore
+all modified paths.
+
+-W::
+--worktree::
+-S::
+--staged::
+	Specify the restore location. If neither option is specified,
+	by default the working tree is restored. Specifying `--staged`
+	will only restore the index. Specifying both restores both.
+
+-q::
+--quiet::
+	Quiet, suppress feedback messages. Implies `--no-progress`.
+
+--progress::
+--no-progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless `--quiet`
+	is specified. This flag enables progress reporting even if not
+	attached to a terminal, regardless of `--quiet`.
+
+--ours::
+--theirs::
+	When restoring files in the working tree from the index, use
+	stage #2 ('ours') or #3 ('theirs') for unmerged paths.
++
+Note that during `git rebase` and `git pull --rebase`, 'ours' and
+'theirs' may appear swapped. See the explanation of the same options
+in linkgit:git-checkout[1] for details.
+
+-m::
+--merge::
+	When restoring files on the working tree from the index,
+	recreate the conflicted merge in the unmerged paths.
+
+--conflict=<style>::
+	The same as `--merge` option above, but changes the way the
+	conflicting hunks are presented, overriding the
+	`merge.conflictStyle` configuration variable.  Possible values
+	are "merge" (default) and "diff3" (in addition to what is
+	shown by "merge" style, shows the original contents).
+
+--ignore-unmerged::
+	When restoring files on the working tree from the index, do
+	not abort the operation if there are unmerged entries and
+	neither `--ours`, `--theirs`, `--merge` or `--conflict` is
+	specified. Unmerged paths on the working tree are left alone.
+
+--ignore-skip-worktree-bits::
+	In sparse checkout mode, by default is to only update entries
+	matched by `<pathspec>` and sparse patterns in
+	$GIT_DIR/info/sparse-checkout. This option ignores the sparse
+	patterns and unconditionally restores any files in
+	`<pathspec>`.
+
+--overlay::
+--no-overlay::
+	In overlay mode, the command never removes files when
+	restoring. In no-overlay mode, tracked files that do not
+	appear in the `--source` tree are removed, to make them match
+	`<tree>` exactly. The default is no-overlay mode.
+
+EXAMPLES
+--------
+
+The following sequence switches to the `master` branch, reverts the
+`Makefile` to two revisions back, deletes hello.c by mistake, and gets
+it back from the index.
+
+------------
+$ git switch master
+$ git restore --source master~2 Makefile  <1>
+$ rm -f hello.c
+$ git restore hello.c                     <2>
+------------
+
+<1> take a file out of another commit
+<2> restore hello.c from the index
+
+If you want to restore _all_ C source files to match the version in
+the index, you can say
+
+------------
+$ git restore '*.c'
+------------
+
+Note the quotes around `*.c`.  The file `hello.c` will also be
+restored, even though it is no longer in the working tree, because the
+file globbing is used to match entries in the index (not in the
+working tree by the shell).
+
+To restore all files in the current directory
+
+------------
+$ git restore .
+------------
+
+or to restore all working tree files with 'top' pathspec magic (see
+linkgit:gitglossary[7])
+
+------------
+$ git restore :/
+------------
+
+To restore a file in the index to match the version in `HEAD` (this is
+the same as using linkgit:git-reset[1])
+
+------------
+$ git restore --staged hello.c
+------------
+
+or you can restore both the index and the working tree (this the same
+as using linkgit:git-checkout[1])
+
+------------
+$ git restore --source=HEAD --staged --worktree hello.c
+------------
+
+or the short form which is more practical but less readable:
+
+------------
+$ git restore -s@ -SW hello.c
+------------
+
+SEE ALSO
+--------
+linkgit:git-checkout[1],
+linkgit:git-reset[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Documentation/git-revert.txt b/Documentation/git-revert.txt
index 837707a..018ecf4 100644
--- a/Documentation/git-revert.txt
+++ b/Documentation/git-revert.txt
@@ -30,6 +30,9 @@ should see linkgit:git-checkout[1], specifically the `git checkout
 <commit> -- <filename>` syntax.  Take care with these alternatives as
 both will discard uncommitted changes in your working directory.
 
+See "Reset, restore and revert" in linkgit:git[1] for the differences
+between the three commands.
+
 OPTIONS
 -------
 <commit>...::
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 00156d6..fbed007 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -210,6 +210,26 @@ people via patch over e-mail.
 
 include::cmds-foreignscminterface.txt[]
 
+Reset, restore and revert
+~~~~~~~~~~~~~~~~~~~~~~~~~
+There are three commands with similar names: `git reset`,
+`git restore` and `git revert`.
+
+* linkgit:git-revert[1] is about making a new commit that reverts the
+  changes made by other commits.
+
+* linkgit:git-restore[1] is about restoring files in the working tree
+  from either the index or another commit. This command does not
+  update your branch. The command can also be used to restore files in
+  the index from another commit.
+
+* linkgit:git-reset[1] is about updating your branch, moving the tip
+  in order to add or remove commits from the branch. This operation
+  changes the commit history.
++
+`git reset` can also be used to restore the index, overlapping with
+`git restore`.
+
 
 Low-level commands (plumbing)
 -----------------------------
diff --git a/Documentation/gitcli.txt b/Documentation/gitcli.txt
index 592e06d..225513e 100644
--- a/Documentation/gitcli.txt
+++ b/Documentation/gitcli.txt
@@ -209,6 +209,18 @@ See also http://marc.info/?l=git&m=116563135620359 and
 http://marc.info/?l=git&m=119150393620273 for further
 information.
 
+Some other commands that also work on files in the working tree and/or
+in the index can take `--staged` and/or `--worktree`.
+
+* `--staged` is exactly like `--cached`, which is used to ask a
+  command to only work on the index, not the working tree.
+
+* `--worktree` is the opposite, to ask a command to work on the
+  working tree only, not the index.
+
+* The two options can be specified together to ask a command to work
+  on both the index and the working tree.
+
 GIT
 ---
 Part of the linkgit:git[1] suite
diff --git a/Makefile b/Makefile
index f85f364..783b077 100644
--- a/Makefile
+++ b/Makefile
@@ -799,6 +799,7 @@ BUILT_INS += git-format-patch$X
 BUILT_INS += git-fsck-objects$X
 BUILT_INS += git-init$X
 BUILT_INS += git-merge-subtree$X
+BUILT_INS += git-restore$X
 BUILT_INS += git-show$X
 BUILT_INS += git-stage$X
 BUILT_INS += git-status$X
diff --git a/builtin.h b/builtin.h
index c64e444..6830000 100644
--- a/builtin.h
+++ b/builtin.h
@@ -214,6 +214,7 @@ extern int cmd_remote_fd(int argc, const char **argv, const char *prefix);
 extern int cmd_repack(int argc, const char **argv, const char *prefix);
 extern int cmd_rerere(int argc, const char **argv, const char *prefix);
 extern int cmd_reset(int argc, const char **argv, const char *prefix);
+extern int cmd_restore(int argc, const char **argv, const char *prefix);
 extern int cmd_rev_list(int argc, const char **argv, const char *prefix);
 extern int cmd_rev_parse(int argc, const char **argv, const char *prefix);
 extern int cmd_revert(int argc, const char **argv, const char *prefix);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 0351735..98dc2de 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -38,6 +38,11 @@ static const char * const switch_branch_usage[] = {
 	NULL,
 };
 
+static const char * const restore_usage[] = {
+	N_("git restore [<options>] [<branch>] -- <file>..."),
+	NULL,
+};
+
 struct checkout_opts {
 	int patch_mode;
 	int quiet;
@@ -1622,3 +1627,24 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	FREE_AND_NULL(options);
 	return ret;
 }
+
+int cmd_restore(int argc, const char **argv, const char *prefix)
+{
+	struct checkout_opts opts;
+	struct option *options = NULL;
+	int ret;
+
+	memset(&opts, 0, sizeof(opts));
+	opts.dwim_new_local_branch = 1;
+	opts.switch_branch_doing_nothing_is_ok = 0;
+	opts.accept_pathspec = 1;
+
+	options = parse_options_dup(options);
+	options = add_common_options(&opts, options);
+	options = add_checkout_path_options(&opts, options);
+
+	ret = checkout_main(argc, argv, prefix, &opts,
+			    options, restore_usage);
+	FREE_AND_NULL(options);
+	return ret;
+}
diff --git a/command-list.txt b/command-list.txt
index 13317f4..b9eae1c 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -151,6 +151,7 @@ git-replace                             ancillarymanipulators           complete
 git-request-pull                        foreignscminterface             complete
 git-rerere                              ancillaryinterrogators
 git-reset                               mainporcelain           worktree
+git-restore                             mainporcelain           worktree
 git-revert                              mainporcelain
 git-rev-list                            plumbinginterrogators
 git-rev-parse                           plumbinginterrogators
diff --git a/git.c b/git.c
index 39582cf..6d439e7 100644
--- a/git.c
+++ b/git.c
@@ -558,6 +558,7 @@ static struct cmd_struct commands[] = {
 	{ "replace", cmd_replace, RUN_SETUP },
 	{ "rerere", cmd_rerere, RUN_SETUP },
 	{ "reset", cmd_reset, RUN_SETUP },
+	{ "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
 	{ "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
 	{ "rev-parse", cmd_rev_parse, NO_PARSEOPT },
 	{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
-- 
cgit v0.10.2-6-g49f6


From c9c935f6d4519c53f27f50113bea2c17deb8b71e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:46 +0700
Subject: restore: take tree-ish from --source option instead
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This is another departure from 'git checkout' syntax, which uses -- to
separate ref and pathspec. The observation is restore (or "git
checkout -- <pathspec>") is most often used to restore some files from
the index. If this is correct, we can simplify it by taking away the
ref, so that we can write

    git restore some-file

without worrying about some-file being a ref and whether we need to do

    git restore -- some-file

for safety. If the source of the restore comes from a tree, it will be
in the form of an option with value, e.g.

    git restore --source=this-tree some-file

This is of course longer to type than using "--". But hopefully it
will not be used as often, and it is clearly easier to understand.

dwim_new_local_branch is no longer set (or unset) in cmd_restore_files()
because it's irrelevant because we don't really care about dwim-ing.
With accept_ref being unset, dwim can't happen.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 98dc2de..5aba345 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -39,7 +39,7 @@ static const char * const switch_branch_usage[] = {
 };
 
 static const char * const restore_usage[] = {
-	N_("git restore [<options>] [<branch>] -- <file>..."),
+	N_("git restore [<options>] [--source=<branch>] <file>..."),
 	NULL,
 };
 
@@ -59,6 +59,7 @@ struct checkout_opts {
 	int overlay_mode;
 	int dwim_new_local_branch;
 	int discard_changes;
+	int accept_ref;
 	int accept_pathspec;
 	int switch_branch_doing_nothing_is_ok;
 	int only_merge_on_switching_branches;
@@ -76,6 +77,7 @@ struct checkout_opts {
 	int branch_exists;
 	const char *prefix;
 	struct pathspec pathspec;
+	const char *from_treeish;
 	struct tree *source_tree;
 };
 
@@ -1410,6 +1412,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 {
 	struct branch_info new_branch_info;
 	int dwim_remotes_matched = 0;
+	int parseopt_flags = 0;
 
 	memset(&new_branch_info, 0, sizeof(new_branch_info));
 	opts->overwrite_ignore = 1;
@@ -1421,8 +1424,13 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 
 	opts->track = BRANCH_TRACK_UNSPECIFIED;
 
-	argc = parse_options(argc, argv, prefix, options, usagestr,
-			     PARSE_OPT_KEEP_DASHDASH);
+	if (!opts->accept_pathspec && !opts->accept_ref)
+		BUG("make up your mind, you need to take _something_");
+	if (opts->accept_pathspec && opts->accept_ref)
+		parseopt_flags = PARSE_OPT_KEEP_DASHDASH;
+
+	argc = parse_options(argc, argv, prefix, options,
+			     usagestr, parseopt_flags);
 
 	if (opts->show_progress < 0) {
 		if (opts->quiet)
@@ -1481,7 +1489,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 	 * including "last branch" syntax and DWIM-ery for names of
 	 * remote branches, erroring out for invalid or ambiguous cases.
 	 */
-	if (argc) {
+	if (argc && opts->accept_ref) {
 		struct object_id rev;
 		int dwim_ok =
 			!opts->patch_mode &&
@@ -1493,6 +1501,18 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 					     &dwim_remotes_matched);
 		argv += n;
 		argc -= n;
+	} else if (!opts->accept_ref && opts->from_treeish) {
+		struct object_id rev;
+
+		if (get_oid_mb(opts->from_treeish, &rev))
+			die(_("could not resolve %s"), opts->from_treeish);
+
+		setup_new_branch_info_and_source_tree(&new_branch_info,
+						      opts, &rev,
+						      opts->from_treeish);
+
+		if (!opts->source_tree)
+			die(_("reference is not a tree: %s"), opts->from_treeish);
 	}
 
 	if (argc) {
@@ -1576,6 +1596,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.dwim_new_local_branch = 1;
 	opts.switch_branch_doing_nothing_is_ok = 1;
 	opts.only_merge_on_switching_branches = 0;
+	opts.accept_ref = 1;
 	opts.accept_pathspec = 1;
 	opts.implicit_detach = 1;
 	opts.can_switch_when_in_progress = 1;
@@ -1611,6 +1632,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 
 	memset(&opts, 0, sizeof(opts));
 	opts.dwim_new_local_branch = 1;
+	opts.accept_ref = 1;
 	opts.accept_pathspec = 0;
 	opts.switch_branch_doing_nothing_is_ok = 0;
 	opts.only_merge_on_switching_branches = 1;
@@ -1631,15 +1653,19 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 int cmd_restore(int argc, const char **argv, const char *prefix)
 {
 	struct checkout_opts opts;
-	struct option *options = NULL;
+	struct option *options;
+	struct option restore_options[] = {
+		OPT_STRING('s', "source", &opts.from_treeish, "<tree-ish>",
+			   N_("where the checkout from")),
+		OPT_END()
+	};
 	int ret;
 
 	memset(&opts, 0, sizeof(opts));
-	opts.dwim_new_local_branch = 1;
-	opts.switch_branch_doing_nothing_is_ok = 0;
+	opts.accept_ref = 0;
 	opts.accept_pathspec = 1;
 
-	options = parse_options_dup(options);
+	options = parse_options_dup(restore_options);
 	options = add_common_options(&opts, options);
 	options = add_checkout_path_options(&opts, options);
 
-- 
cgit v0.10.2-6-g49f6


From be8ed5022b84fa75c24f24bbf64bb5ad6652c64f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:47 +0700
Subject: restore: make pathspec mandatory
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"git restore" without arguments does not make much sense when
it's about restoring files (what files now?). We could default to
either

    git restore .

or

    git restore :/

Neither is intuitive. Make the user always give pathspec, force the
user to think the scope of restore they want because this is a
destructive operation.

"git restore -p" without pathspec is an exception to this
because it really is a separate mode. It will be treated as running
patch mode on the whole worktree.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5aba345..77db523 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -65,6 +65,7 @@ struct checkout_opts {
 	int only_merge_on_switching_branches;
 	int can_switch_when_in_progress;
 	int orphan_from_empty_tree;
+	int empty_pathspec_ok;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -1515,6 +1516,10 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 			die(_("reference is not a tree: %s"), opts->from_treeish);
 	}
 
+	if (opts->accept_pathspec && !opts->empty_pathspec_ok && !argc &&
+	    !opts->patch_mode)	/* patch mode is special */
+		die(_("you must specify path(s) to restore"));
+
 	if (argc) {
 		parse_pathspec(&opts->pathspec, 0,
 			       opts->patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0,
@@ -1601,6 +1606,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.implicit_detach = 1;
 	opts.can_switch_when_in_progress = 1;
 	opts.orphan_from_empty_tree = 0;
+	opts.empty_pathspec_ok = 1;
 
 	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
@@ -1664,6 +1670,7 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
 	memset(&opts, 0, sizeof(opts));
 	opts.accept_ref = 0;
 	opts.accept_pathspec = 1;
+	opts.empty_pathspec_ok = 0;
 
 	options = parse_options_dup(restore_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From a6cfb9ba360d975dd38b2e6e77a88d2c8fe8d323 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:48 +0700
Subject: restore: disable overlay mode by default
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Overlay mode is considered confusing when the command is about
restoring files on worktree. Disable it by default. The user can still
turn it on, or use 'git checkout' which still has overlay mode on by
default.

While at it, make the check in checkout_branch() stricter. Neither
--overlay or --no-overlay should be accepted in branch switching mode.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 77db523..9c5abe1 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1274,9 +1274,9 @@ static int checkout_branch(struct checkout_opts *opts,
 		die(_("'%s' cannot be used with switching branches"),
 		    "--patch");
 
-	if (!opts->overlay_mode)
+	if (opts->overlay_mode != -1)
 		die(_("'%s' cannot be used with switching branches"),
-		    "--no-overlay");
+		    "--[no]-overlay");
 
 	if (opts->writeout_stage)
 		die(_("'%s' cannot be used with switching branches"),
@@ -1399,7 +1399,6 @@ static struct option *add_checkout_path_options(struct checkout_opts *opts,
 		OPT_BOOL('p', "patch", &opts->patch_mode, N_("select hunks interactively")),
 		OPT_BOOL(0, "ignore-skip-worktree-bits", &opts->ignore_skipworktree,
 			 N_("do not limit pathspecs to sparse entries only")),
-		OPT_BOOL(0, "overlay", &opts->overlay_mode, N_("use overlay mode (default)")),
 		OPT_END()
 	};
 	struct option *newopts = parse_options_concat(prevopts, options);
@@ -1419,7 +1418,6 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 	opts->overwrite_ignore = 1;
 	opts->prefix = prefix;
 	opts->show_progress = -1;
-	opts->overlay_mode = -1;
 
 	git_config(git_checkout_config, opts);
 
@@ -1593,6 +1591,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		OPT_BOOL('l', NULL, &opts.new_branch_log, N_("create reflog for new branch")),
 		OPT_BOOL(0, "guess", &opts.dwim_new_local_branch,
 			 N_("second guess 'git checkout <no-such-branch>' (default)")),
+		OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")),
 		OPT_END()
 	};
 	int ret;
@@ -1607,6 +1606,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.can_switch_when_in_progress = 1;
 	opts.orphan_from_empty_tree = 0;
 	opts.empty_pathspec_ok = 1;
+	opts.overlay_mode = -1;
 
 	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
@@ -1645,6 +1645,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
 	opts.implicit_detach = 0;
 	opts.can_switch_when_in_progress = 0;
 	opts.orphan_from_empty_tree = 1;
+	opts.overlay_mode = -1;
 
 	options = parse_options_dup(switch_options);
 	options = add_common_options(&opts, options);
@@ -1663,6 +1664,7 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
 	struct option restore_options[] = {
 		OPT_STRING('s', "source", &opts.from_treeish, "<tree-ish>",
 			   N_("where the checkout from")),
+		OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode")),
 		OPT_END()
 	};
 	int ret;
@@ -1671,6 +1673,7 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
 	opts.accept_ref = 0;
 	opts.accept_pathspec = 1;
 	opts.empty_pathspec_ok = 0;
+	opts.overlay_mode = 0;
 
 	options = parse_options_dup(restore_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From 4058199c0ec5b68ffa2225dcdf5235a328f2443e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:49 +0700
Subject: checkout: factor out worktree checkout code
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 9c5abe1..1753c8c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -330,17 +330,73 @@ static void mark_ce_for_checkout_no_overlay(struct cache_entry *ce,
 	}
 }
 
+static int checkout_worktree(const struct checkout_opts *opts)
+{
+	struct checkout state = CHECKOUT_INIT;
+	int nr_checkouts = 0, nr_unmerged = 0;
+	int errs = 0;
+	int pos;
+
+	state.force = 1;
+	state.refresh_cache = 1;
+	state.istate = &the_index;
+
+	enable_delayed_checkout(&state);
+	for (pos = 0; pos < active_nr; pos++) {
+		struct cache_entry *ce = active_cache[pos];
+		if (ce->ce_flags & CE_MATCHED) {
+			if (!ce_stage(ce)) {
+				errs |= checkout_entry(ce, &state,
+						       NULL, &nr_checkouts);
+				continue;
+			}
+			if (opts->writeout_stage)
+				errs |= checkout_stage(opts->writeout_stage,
+						       ce, pos,
+						       &state,
+						       &nr_checkouts, opts->overlay_mode);
+			else if (opts->merge)
+				errs |= checkout_merged(pos, &state,
+							&nr_unmerged);
+			pos = skip_same_name(ce, pos) - 1;
+		}
+	}
+	remove_marked_cache_entries(&the_index, 1);
+	remove_scheduled_dirs();
+	errs |= finish_delayed_checkout(&state, &nr_checkouts);
+
+	if (opts->count_checkout_paths) {
+		if (nr_unmerged)
+			fprintf_ln(stderr, Q_("Recreated %d merge conflict",
+					      "Recreated %d merge conflicts",
+					      nr_unmerged),
+				   nr_unmerged);
+		if (opts->source_tree)
+			fprintf_ln(stderr, Q_("Updated %d path from %s",
+					      "Updated %d paths from %s",
+					      nr_checkouts),
+				   nr_checkouts,
+				   find_unique_abbrev(&opts->source_tree->object.oid,
+						      DEFAULT_ABBREV));
+		else if (!nr_unmerged || nr_checkouts)
+			fprintf_ln(stderr, Q_("Updated %d path from the index",
+					      "Updated %d paths from the index",
+					      nr_checkouts),
+				   nr_checkouts);
+	}
+
+	return errs;
+}
+
 static int checkout_paths(const struct checkout_opts *opts,
 			  const char *revision)
 {
 	int pos;
-	struct checkout state = CHECKOUT_INIT;
 	static char *ps_matched;
 	struct object_id rev;
 	struct commit *head;
 	int errs = 0;
 	struct lock_file lock_file = LOCK_INIT;
-	int nr_checkouts = 0, nr_unmerged = 0;
 
 	trace2_cmd_mode(opts->patch_mode ? "patch" : "path");
 
@@ -426,53 +482,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 		return 1;
 
 	/* Now we are committed to check them out */
-	state.force = 1;
-	state.refresh_cache = 1;
-	state.istate = &the_index;
-
-	enable_delayed_checkout(&state);
-	for (pos = 0; pos < active_nr; pos++) {
-		struct cache_entry *ce = active_cache[pos];
-		if (ce->ce_flags & CE_MATCHED) {
-			if (!ce_stage(ce)) {
-				errs |= checkout_entry(ce, &state,
-						       NULL, &nr_checkouts);
-				continue;
-			}
-			if (opts->writeout_stage)
-				errs |= checkout_stage(opts->writeout_stage,
-						       ce, pos,
-						       &state,
-						       &nr_checkouts, opts->overlay_mode);
-			else if (opts->merge)
-				errs |= checkout_merged(pos, &state,
-							&nr_unmerged);
-			pos = skip_same_name(ce, pos) - 1;
-		}
-	}
-	remove_marked_cache_entries(&the_index, 1);
-	remove_scheduled_dirs();
-	errs |= finish_delayed_checkout(&state, &nr_checkouts);
-
-	if (opts->count_checkout_paths) {
-		if (nr_unmerged)
-			fprintf_ln(stderr, Q_("Recreated %d merge conflict",
-					      "Recreated %d merge conflicts",
-					      nr_unmerged),
-				   nr_unmerged);
-		if (opts->source_tree)
-			fprintf_ln(stderr, Q_("Updated %d path from %s",
-					      "Updated %d paths from %s",
-					      nr_checkouts),
-				   nr_checkouts,
-				   find_unique_abbrev(&opts->source_tree->object.oid,
-						      DEFAULT_ABBREV));
-		else if (!nr_unmerged || nr_checkouts)
-			fprintf_ln(stderr, Q_("Updated %d path from the index",
-					      "Updated %d paths from the index",
-					      nr_checkouts),
-				   nr_checkouts);
-	}
+	errs |= checkout_worktree(opts);
 
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
-- 
cgit v0.10.2-6-g49f6


From 183fb44fd234499ed76d72d745ccb480b25f6d15 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:50 +0700
Subject: restore: add --worktree and --staged
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

'git checkout <tree-ish> <pathspec>' updates both index and
worktree. But updating the index when you want to restore worktree
files is non-intuitive. The index contains the data ready for the next
commit, and there's no indication that the user will want to commit
the restored versions.

'git restore' therefore by default only touches worktree. The user has
the option to update either the index with

    git restore --staged --source=<tree> <path>  (1)

or update both with

    git restore --staged --worktree --source=<tree> <path> (2)

PS. Orignally I wanted to make worktree update default and form (1)
would add index update while also updating the worktree, and the user
would need to do "--staged --no-worktree" to update index only. But it
looks really confusing that "--staged" option alone updates both. So
now form (2) is used for both, which reads much more obvious.

PPS. Yes form (1) overlaps with "git reset <rev> <path>". I don't know
if we can ever turn "git reset" back to "_always_ reset HEAD and
optionally do something else".

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 1753c8c..e855c64 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -66,6 +66,8 @@ struct checkout_opts {
 	int can_switch_when_in_progress;
 	int orphan_from_empty_tree;
 	int empty_pathspec_ok;
+	int checkout_index;
+	int checkout_worktree;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -397,6 +399,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 	struct commit *head;
 	int errs = 0;
 	struct lock_file lock_file = LOCK_INIT;
+	int checkout_index;
 
 	trace2_cmd_mode(opts->patch_mode ? "patch" : "path");
 
@@ -422,9 +425,26 @@ static int checkout_paths(const struct checkout_opts *opts,
 		die(_("Cannot update paths and switch to branch '%s' at the same time."),
 		    opts->new_branch);
 
-	if (opts->patch_mode)
-		return run_add_interactive(revision, "--patch=checkout",
-					   &opts->pathspec);
+	if (!opts->checkout_worktree && !opts->checkout_index)
+		die(_("neither '%s' or '%s' is specified"),
+		    "--staged", "--worktree");
+
+	if (!opts->checkout_worktree && !opts->from_treeish)
+		die(_("'%s' must be used when '%s' is not specified"),
+		    "--worktree", "--source");
+
+	if (opts->patch_mode) {
+		const char *patch_mode;
+
+		if (opts->checkout_index && opts->checkout_worktree)
+			patch_mode = "--patch=checkout";
+		else if (opts->checkout_index && !opts->checkout_worktree)
+			patch_mode = "--patch=reset";
+		else
+			die(_("'%s' with only '%s' is not currently supported"),
+			    "--patch", "--worktree");
+		return run_add_interactive(revision, patch_mode, &opts->pathspec);
+	}
 
 	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
 	if (read_cache_preload(&opts->pathspec) < 0)
@@ -482,10 +502,30 @@ static int checkout_paths(const struct checkout_opts *opts,
 		return 1;
 
 	/* Now we are committed to check them out */
-	errs |= checkout_worktree(opts);
+	if (opts->checkout_worktree)
+		errs |= checkout_worktree(opts);
 
-	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
-		die(_("unable to write new index file"));
+	/*
+	 * Allow updating the index when checking out from the index.
+	 * This is to save new stat info.
+	 */
+	if (opts->checkout_worktree && !opts->checkout_index && !opts->source_tree)
+		checkout_index = 1;
+	else
+		checkout_index = opts->checkout_index;
+
+	if (checkout_index) {
+		if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
+			die(_("unable to write new index file"));
+	} else {
+		/*
+		 * NEEDSWORK: if --worktree is not specified, we
+		 * should save stat info of checked out files in the
+		 * index to avoid the next (potentially costly)
+		 * refresh. But it's a bit tricker to do...
+		 */
+		rollback_lock_file(&lock_file);
+	}
 
 	read_ref_full("HEAD", 0, &rev, NULL);
 	head = lookup_commit_reference_gently(the_repository, &rev, 1);
@@ -1461,6 +1501,20 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 	if (opts->overlay_mode == 1 && opts->patch_mode)
 		die(_("-p and --overlay are mutually exclusive"));
 
+	if (opts->checkout_index >= 0 || opts->checkout_worktree >= 0) {
+		if (opts->checkout_index < 0)
+			opts->checkout_index = 0;
+		if (opts->checkout_worktree < 0)
+			opts->checkout_worktree = 0;
+	} else {
+		if (opts->checkout_index < 0)
+			opts->checkout_index = -opts->checkout_index - 1;
+		if (opts->checkout_worktree < 0)
+			opts->checkout_worktree = -opts->checkout_worktree - 1;
+	}
+	if (opts->checkout_index < 0 || opts->checkout_worktree < 0)
+		BUG("these flags should be non-negative by now");
+
 	/*
 	 * From here on, new_branch will contain the branch to be checked out,
 	 * and new_branch_force and new_orphan_branch will tell us which one of
@@ -1617,6 +1671,8 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	opts.orphan_from_empty_tree = 0;
 	opts.empty_pathspec_ok = 1;
 	opts.overlay_mode = -1;
+	opts.checkout_index = -2;    /* default on */
+	opts.checkout_worktree = -2; /* default on */
 
 	options = parse_options_dup(checkout_options);
 	options = add_common_options(&opts, options);
@@ -1674,6 +1730,10 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
 	struct option restore_options[] = {
 		OPT_STRING('s', "source", &opts.from_treeish, "<tree-ish>",
 			   N_("where the checkout from")),
+		OPT_BOOL('S', "staged", &opts.checkout_index,
+			   N_("restore the index")),
+		OPT_BOOL('W', "worktree", &opts.checkout_worktree,
+			   N_("restore the working tree (default)")),
 		OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode")),
 		OPT_END()
 	};
@@ -1684,6 +1744,8 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
 	opts.accept_pathspec = 1;
 	opts.empty_pathspec_ok = 0;
 	opts.overlay_mode = 0;
+	opts.checkout_index = -1;    /* default off */
+	opts.checkout_worktree = -2; /* default on */
 
 	options = parse_options_dup(restore_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From e3ddd3b5e583e62d874f56f8c88603ad0ebafd5e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:51 +0700
Subject: restore: reject invalid combinations with --staged
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

git-checkout rejects plenty of invalid option combinations. Since
git-checkout is equivalent of either

    git restore --source --staged --worktree

or

    git restore --worktree

that still leaves the new mode 'git restore --index' unprotected. Reject
some more invalid option combinations.

The other new mode 'restore --source --worktree' does not need anything
else.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index e855c64..71e2589 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -433,6 +433,16 @@ static int checkout_paths(const struct checkout_opts *opts,
 		die(_("'%s' must be used when '%s' is not specified"),
 		    "--worktree", "--source");
 
+	if (opts->checkout_index && !opts->checkout_worktree &&
+	    opts->writeout_stage)
+		die(_("'%s' or '%s' cannot be used with %s"),
+		    "--ours", "--theirs", "--staged");
+
+	if (opts->checkout_index && !opts->checkout_worktree &&
+	    opts->merge)
+		die(_("'%s' or '%s' cannot be used with %s"),
+		    "--merge", "--conflict", "--staged");
+
 	if (opts->patch_mode) {
 		const char *patch_mode;
 
-- 
cgit v0.10.2-6-g49f6


From 3a733ce5237570460bbb63e20002b92e903ad65f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:52 +0700
Subject: restore: default to --source=HEAD when only --staged is specified
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

"git restore --staged" without --source does not make much sense since
by default we restore from the index.  Instead of copying the index to
itself, set the default source to HEAD in this case, yielding behavior
that matches "git reset -- <paths>".

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 71e2589..09a03f1 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1524,6 +1524,12 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 	}
 	if (opts->checkout_index < 0 || opts->checkout_worktree < 0)
 		BUG("these flags should be non-negative by now");
+	/*
+	 * convenient shortcut: "git restore --staged" equals
+	 * "git restore --staged --source HEAD"
+	 */
+	if (!opts->from_treeish && opts->checkout_index && !opts->checkout_worktree)
+		opts->from_treeish = "HEAD";
 
 	/*
 	 * From here on, new_branch will contain the branch to be checked out,
-- 
cgit v0.10.2-6-g49f6


From a5e5f399ca89cea574d11704d625a7b28b53de76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:53 +0700
Subject: restore: replace --force with --ignore-unmerged
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Use a more specific option name to express its purpose. --force may come
back as an alias of --ignore-unmerged and possibly more. But since this
is a destructive operation, I don't see why we need to "force" anything
more. We already don't hold back.

When 'checkout --force' or 'restore --ignore-unmerged' is used, we may
also print warnings about unmerged entries being ignore. Since this is
not exactly warning (people tell us to do so), more informational, let
it be suppressed if --quiet is given. This is a behavior change for
git-checkout.

PS. The diff looks a bit iffy since --force is moved to
add_common_switch_branch_options() (i.e. for switching). But
git-checkout is also doing switching and inherits this --force.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 09a03f1..824ab65 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -68,6 +68,8 @@ struct checkout_opts {
 	int empty_pathspec_ok;
 	int checkout_index;
 	int checkout_worktree;
+	const char *ignore_unmerged_opt;
+	int ignore_unmerged;
 
 	const char *new_branch;
 	const char *new_branch_force;
@@ -409,8 +411,9 @@ static int checkout_paths(const struct checkout_opts *opts,
 	if (opts->new_branch_log)
 		die(_("'%s' cannot be used with updating paths"), "-l");
 
-	if (opts->force && opts->patch_mode)
-		die(_("'%s' cannot be used with updating paths"), "-f");
+	if (opts->ignore_unmerged && opts->patch_mode)
+		die(_("'%s' cannot be used with updating paths"),
+		    opts->ignore_unmerged_opt);
 
 	if (opts->force_detach)
 		die(_("'%s' cannot be used with updating paths"), "--detach");
@@ -418,8 +421,9 @@ static int checkout_paths(const struct checkout_opts *opts,
 	if (opts->merge && opts->patch_mode)
 		die(_("'%s' cannot be used with %s"), "--merge", "--patch");
 
-	if (opts->force && opts->merge)
-		die(_("'%s' cannot be used with %s"), "-f", "-m");
+	if (opts->ignore_unmerged && opts->merge)
+		die(_("'%s' cannot be used with %s"),
+		    opts->ignore_unmerged_opt, "-m");
 
 	if (opts->new_branch)
 		die(_("Cannot update paths and switch to branch '%s' at the same time."),
@@ -495,8 +499,9 @@ static int checkout_paths(const struct checkout_opts *opts,
 		if (ce->ce_flags & CE_MATCHED) {
 			if (!ce_stage(ce))
 				continue;
-			if (opts->force) {
-				warning(_("path '%s' is unmerged"), ce->name);
+			if (opts->ignore_unmerged) {
+				if (!opts->quiet)
+					warning(_("path '%s' is unmerged"), ce->name);
 			} else if (opts->writeout_stage) {
 				errs |= check_stage(opts->writeout_stage, ce, pos, opts->overlay_mode);
 			} else if (opts->merge) {
@@ -1414,8 +1419,6 @@ static struct option *add_common_options(struct checkout_opts *opts,
 			    "checkout", "control recursive updating of submodules",
 			    PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater },
 		OPT_BOOL(0, "progress", &opts->show_progress, N_("force progress reporting")),
-		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
-			   PARSE_OPT_NOCOMPLETE),
 		OPT_BOOL('m', "merge", &opts->merge, N_("perform a 3-way merge with the new branch")),
 		OPT_STRING(0, "conflict", &opts->conflict_style, N_("style"),
 			   N_("conflict style (merge or diff3)")),
@@ -1433,6 +1436,8 @@ static struct option *add_common_switch_branch_options(
 		OPT_BOOL('d', "detach", &opts->force_detach, N_("detach HEAD at named commit")),
 		OPT_SET_INT('t', "track",  &opts->track, N_("set upstream info for new branch"),
 			BRANCH_TRACK_EXPLICIT),
+		OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"),
+			   PARSE_OPT_NOCOMPLETE),
 		OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
 		OPT_BOOL_F(0, "overwrite-ignore", &opts->overwrite_ignore,
 			   N_("update ignored files (default)"),
@@ -1502,8 +1507,11 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 		opts->merge = 1; /* implied */
 		git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
 	}
-	if (opts->force)
+	if (opts->force) {
 		opts->discard_changes = 1;
+		opts->ignore_unmerged_opt = "--force";
+		opts->ignore_unmerged = 1;
+	}
 
 	if ((!!opts->new_branch + !!opts->new_branch_force + !!opts->new_orphan_branch) > 1)
 		die(_("-b, -B and --orphan are mutually exclusive"));
@@ -1750,6 +1758,8 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
 			   N_("restore the index")),
 		OPT_BOOL('W', "worktree", &opts.checkout_worktree,
 			   N_("restore the working tree (default)")),
+		OPT_BOOL(0, "ignore-unmerged", &opts.ignore_unmerged,
+			 N_("ignore unmerged entries")),
 		OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode")),
 		OPT_END()
 	};
@@ -1762,6 +1772,7 @@ int cmd_restore(int argc, const char **argv, const char *prefix)
 	opts.overlay_mode = 0;
 	opts.checkout_index = -1;    /* default off */
 	opts.checkout_worktree = -2; /* default on */
+	opts.ignore_unmerged_opt = "--ignore-unmerged";
 
 	options = parse_options_dup(restore_options);
 	options = add_common_options(&opts, options);
-- 
cgit v0.10.2-6-g49f6


From 2f0896ec3ad4731d970d22f61daf62046bc766a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:54 +0700
Subject: restore: support --patch
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

git-restore is different from git-checkout that it only restores the
worktree by default, not both worktree and index. add--interactive
needs some update to support this mode.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 824ab65..bed79ae 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -454,9 +454,11 @@ static int checkout_paths(const struct checkout_opts *opts,
 			patch_mode = "--patch=checkout";
 		else if (opts->checkout_index && !opts->checkout_worktree)
 			patch_mode = "--patch=reset";
+		else if (!opts->checkout_index && opts->checkout_worktree)
+			patch_mode = "--patch=worktree";
 		else
-			die(_("'%s' with only '%s' is not currently supported"),
-			    "--patch", "--worktree");
+			BUG("either flag must have been set, worktree=%d, index=%d",
+			    opts->checkout_worktree, opts->checkout_index);
 		return run_add_interactive(revision, patch_mode, &opts->pathspec);
 	}
 
diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 20eb81c..3dfb362 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -149,6 +149,20 @@ my %patch_modes = (
 		FILTER => undef,
 		IS_REVERSE => 0,
 	},
+	'worktree_head' => {
+		DIFF => 'diff-index -p',
+		APPLY => sub { apply_patch 'apply -R', @_ },
+		APPLY_CHECK => 'apply -R',
+		FILTER => undef,
+		IS_REVERSE => 1,
+	},
+	'worktree_nothead' => {
+		DIFF => 'diff-index -R -p',
+		APPLY => sub { apply_patch 'apply', @_ },
+		APPLY_CHECK => 'apply',
+		FILTER => undef,
+		IS_REVERSE => 0,
+	},
 );
 
 $patch_mode = 'stage';
@@ -1050,6 +1064,12 @@ marked for discarding."),
 	checkout_nothead => N__(
 "If the patch applies cleanly, the edited hunk will immediately be
 marked for applying."),
+	worktree_head => N__(
+"If the patch applies cleanly, the edited hunk will immediately be
+marked for discarding."),
+	worktree_nothead => N__(
+"If the patch applies cleanly, the edited hunk will immediately be
+marked for applying."),
 );
 
 sub recount_edited_hunk {
@@ -1260,6 +1280,18 @@ n - do not apply this hunk to index and worktree
 q - quit; do not apply this hunk or any of the remaining ones
 a - apply this hunk and all later hunks in the file
 d - do not apply this hunk or any of the later hunks in the file"),
+	worktree_head => N__(
+"y - discard this hunk from worktree
+n - do not discard this hunk from worktree
+q - quit; do not discard this hunk or any of the remaining ones
+a - discard this hunk and all later hunks in the file
+d - do not discard this hunk or any of the later hunks in the file"),
+	worktree_nothead => N__(
+"y - apply this hunk to worktree
+n - do not apply this hunk to worktree
+q - quit; do not apply this hunk or any of the remaining ones
+a - apply this hunk and all later hunks in the file
+d - do not apply this hunk or any of the later hunks in the file"),
 );
 
 sub help_patch_cmd {
@@ -1421,6 +1453,16 @@ my %patch_update_prompt_modes = (
 		deletion => N__("Apply deletion to index and worktree [y,n,q,a,d%s,?]? "),
 		hunk => N__("Apply this hunk to index and worktree [y,n,q,a,d%s,?]? "),
 	},
+	worktree_head => {
+		mode => N__("Discard mode change from worktree [y,n,q,a,d%s,?]? "),
+		deletion => N__("Discard deletion from worktree [y,n,q,a,d%s,?]? "),
+		hunk => N__("Discard this hunk from worktree [y,n,q,a,d%s,?]? "),
+	},
+	worktree_nothead => {
+		mode => N__("Apply mode change to worktree [y,n,q,a,d%s,?]? "),
+		deletion => N__("Apply deletion to worktree [y,n,q,a,d%s,?]? "),
+		hunk => N__("Apply this hunk to worktree [y,n,q,a,d%s,?]? "),
+	},
 );
 
 sub patch_update_file {
@@ -1756,6 +1798,16 @@ sub process_args {
 						       'checkout_head' : 'checkout_nothead');
 					$arg = shift @ARGV or die __("missing --");
 				}
+			} elsif ($1 eq 'worktree') {
+				$arg = shift @ARGV or die __("missing --");
+				if ($arg eq '--') {
+					$patch_mode = 'checkout_index';
+				} else {
+					$patch_mode_revision = $arg;
+					$patch_mode = ($arg eq 'HEAD' ?
+						       'worktree_head' : 'worktree_nothead');
+					$arg = shift @ARGV or die __("missing --");
+				}
 			} elsif ($1 eq 'stage' or $1 eq 'stash') {
 				$patch_mode = $1;
 				$arg = shift @ARGV or die __("missing --");
-- 
cgit v0.10.2-6-g49f6


From 4df3ec6324ba78b9b28ce1ecb872594dd1bffa1c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:55 +0700
Subject: t: add tests for restore
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/lib-patch-mode.sh b/t/lib-patch-mode.sh
index 06c3c91..cfd76bf 100644
--- a/t/lib-patch-mode.sh
+++ b/t/lib-patch-mode.sh
@@ -2,28 +2,40 @@
 
 . ./test-lib.sh
 
+# set_state <path> <worktree-content> <index-content>
+#
+# Prepare the content for path in worktree and the index as specified.
 set_state () {
 	echo "$3" > "$1" &&
 	git add "$1" &&
 	echo "$2" > "$1"
 }
 
+# save_state <path>
+#
+# Save index/worktree content of <path> in the files _worktree_<path>
+# and _index_<path>
 save_state () {
 	noslash="$(echo "$1" | tr / _)" &&
 	cat "$1" > _worktree_"$noslash" &&
 	git show :"$1" > _index_"$noslash"
 }
 
+# set_and_save_state <path> <worktree-content> <index-content>
 set_and_save_state () {
 	set_state "$@" &&
 	save_state "$1"
 }
 
+# verify_state <path> <expected-worktree-content> <expected-index-content>
 verify_state () {
 	test "$(cat "$1")" = "$2" &&
 	test "$(git show :"$1")" = "$3"
 }
 
+# verify_saved_state <path>
+#
+# Call verify_state with expected contents from the last save_state
 verify_saved_state () {
 	noslash="$(echo "$1" | tr / _)" &&
 	verify_state "$1" "$(cat _worktree_"$noslash")" "$(cat _index_"$noslash")"
diff --git a/t/t2070-restore.sh b/t/t2070-restore.sh
new file mode 100755
index 0000000..73ea13e
--- /dev/null
+++ b/t/t2070-restore.sh
@@ -0,0 +1,99 @@
+#!/bin/sh
+
+test_description='restore basic functionality'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	test_commit first &&
+	echo first-and-a-half >>first.t &&
+	git add first.t &&
+	test_commit second &&
+	echo one >one &&
+	echo two >two &&
+	echo untracked >untracked &&
+	echo ignored >ignored &&
+	echo /ignored >.gitignore &&
+	git add one two .gitignore &&
+	git update-ref refs/heads/one master
+'
+
+test_expect_success 'restore without pathspec is not ok' '
+	test_must_fail git restore &&
+	test_must_fail git restore --source=first
+'
+
+test_expect_success 'restore a file, ignoring branch of same name' '
+	cat one >expected &&
+	echo dirty >>one &&
+	git restore one &&
+	test_cmp expected one
+'
+
+test_expect_success 'restore a file on worktree from another ref' '
+	test_when_finished git reset --hard &&
+	git cat-file blob first:./first.t >expected &&
+	git restore --source=first first.t &&
+	test_cmp expected first.t &&
+	git cat-file blob HEAD:./first.t >expected &&
+	git show :first.t >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'restore a file in the index from another ref' '
+	test_when_finished git reset --hard &&
+	git cat-file blob first:./first.t >expected &&
+	git restore --source=first --staged first.t &&
+	git show :first.t >actual &&
+	test_cmp expected actual &&
+	git cat-file blob HEAD:./first.t >expected &&
+	test_cmp expected first.t
+'
+
+test_expect_success 'restore a file in both the index and worktree from another ref' '
+	test_when_finished git reset --hard &&
+	git cat-file blob first:./first.t >expected &&
+	git restore --source=first --staged --worktree first.t &&
+	git show :first.t >actual &&
+	test_cmp expected actual &&
+	test_cmp expected first.t
+'
+
+test_expect_success 'restore --staged uses HEAD as source' '
+	test_when_finished git reset --hard &&
+	git cat-file blob :./first.t >expected &&
+	echo index-dirty >>first.t &&
+	git add first.t &&
+	git restore --staged first.t &&
+	git cat-file blob :./first.t >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'restore --ignore-unmerged ignores unmerged entries' '
+	git init unmerged &&
+	(
+		cd unmerged &&
+		echo one >unmerged &&
+		echo one >common &&
+		git add unmerged common &&
+		git commit -m common &&
+		git switch -c first &&
+		echo first >unmerged &&
+		git commit -am first &&
+		git switch -c second master &&
+		echo second >unmerged &&
+		git commit -am second &&
+		test_must_fail git merge first &&
+
+		echo dirty >>common &&
+		test_must_fail git restore . &&
+
+		git restore --ignore-unmerged --quiet . >output 2>&1 &&
+		git diff common >diff-output &&
+		: >empty &&
+		test_cmp empty output &&
+		test_cmp empty diff-output
+	)
+'
+
+test_done
diff --git a/t/t2071-restore-patch.sh b/t/t2071-restore-patch.sh
new file mode 100755
index 0000000..98b2476
--- /dev/null
+++ b/t/t2071-restore-patch.sh
@@ -0,0 +1,110 @@
+#!/bin/sh
+
+test_description='git restore --patch'
+
+. ./lib-patch-mode.sh
+
+test_expect_success PERL 'setup' '
+	mkdir dir &&
+	echo parent >dir/foo &&
+	echo dummy >bar &&
+	git add bar dir/foo &&
+	git commit -m initial &&
+	test_tick &&
+	test_commit second dir/foo head &&
+	set_and_save_state bar bar_work bar_index &&
+	save_head
+'
+
+test_expect_success PERL 'restore -p without pathspec is fine' '
+	echo q >cmd &&
+	git restore -p <cmd
+'
+
+# note: bar sorts before dir/foo, so the first 'n' is always to skip 'bar'
+
+test_expect_success PERL 'saying "n" does nothing' '
+	set_and_save_state dir/foo work head &&
+	test_write_lines n n | git restore -p &&
+	verify_saved_state bar &&
+	verify_saved_state dir/foo
+'
+
+test_expect_success PERL 'git restore -p' '
+	set_and_save_state dir/foo work head &&
+	test_write_lines n y | git restore -p &&
+	verify_saved_state bar &&
+	verify_state dir/foo head head
+'
+
+test_expect_success PERL 'git restore -p with staged changes' '
+	set_state dir/foo work index &&
+	test_write_lines n y | git restore -p &&
+	verify_saved_state bar &&
+	verify_state dir/foo index index
+'
+
+test_expect_success PERL 'git restore -p --source=HEAD' '
+	set_state dir/foo work index &&
+	# the third n is to get out in case it mistakenly does not apply
+	test_write_lines n y n | git restore -p --source=HEAD &&
+	verify_saved_state bar &&
+	verify_state dir/foo head index
+'
+
+test_expect_success PERL 'git restore -p --source=HEAD^' '
+	set_state dir/foo work index &&
+	# the third n is to get out in case it mistakenly does not apply
+	test_write_lines n y n | git restore -p --source=HEAD^ &&
+	verify_saved_state bar &&
+	verify_state dir/foo parent index
+'
+
+test_expect_success PERL 'git restore -p handles deletion' '
+	set_state dir/foo work index &&
+	rm dir/foo &&
+	test_write_lines n y | git restore -p &&
+	verify_saved_state bar &&
+	verify_state dir/foo index index
+'
+
+# The idea in the rest is that bar sorts first, so we always say 'y'
+# first and if the path limiter fails it'll apply to bar instead of
+# dir/foo.  There's always an extra 'n' to reject edits to dir/foo in
+# the failure case (and thus get out of the loop).
+
+test_expect_success PERL 'path limiting works: dir' '
+	set_state dir/foo work head &&
+	test_write_lines y n | git restore -p dir &&
+	verify_saved_state bar &&
+	verify_state dir/foo head head
+'
+
+test_expect_success PERL 'path limiting works: -- dir' '
+	set_state dir/foo work head &&
+	test_write_lines y n | git restore -p -- dir &&
+	verify_saved_state bar &&
+	verify_state dir/foo head head
+'
+
+test_expect_success PERL 'path limiting works: HEAD^ -- dir' '
+	set_state dir/foo work head &&
+	# the third n is to get out in case it mistakenly does not apply
+	test_write_lines y n n | git restore -p --source=HEAD^ -- dir &&
+	verify_saved_state bar &&
+	verify_state dir/foo parent head
+'
+
+test_expect_success PERL 'path limiting works: foo inside dir' '
+	set_state dir/foo work head &&
+	# the third n is to get out in case it mistakenly does not apply
+	test_write_lines y n n | (cd dir && git restore -p foo) &&
+	verify_saved_state bar &&
+	verify_state dir/foo head head
+'
+
+test_expect_success PERL 'none of this moved HEAD' '
+	verify_saved_head
+'
+
+test_done
-- 
cgit v0.10.2-6-g49f6


From 75f4c7c1eb06cdf6eae1339bbac02dfb620acc11 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:56 +0700
Subject: completion: support restore
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Completion for restore is straightforward. We could still do better
though by giving the list of just tracked files instead of all present
ones. But let's leave it for later.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index b24bc48..58d18d4 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -2491,6 +2491,21 @@ _git_reset ()
 	__git_complete_refs
 }
 
+_git_restore ()
+{
+	case "$cur" in
+	--conflict=*)
+		__gitcomp "diff3 merge" "" "${cur##--conflict=}"
+		;;
+	--source=*)
+		__git_complete_refs --cur="${cur##--source=}"
+		;;
+	--*)
+		__gitcomp_builtin restore
+		;;
+	esac
+}
+
 __git_revert_inprogress_options="--continue --quit --abort"
 
 _git_revert ()
-- 
cgit v0.10.2-6-g49f6


From fc991b43df83ee32a92b9d906e77276e5dbd639c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:57 +0700
Subject: user-manual.txt: prefer 'merge --abort' over 'reset --hard'
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Since the operation in progress is merge, stick to the 'git merge'
variant of aborting. 'git reset --hard' does not really tell you about
aborting the merge by just looking, longer to type, and even though I
know by heart what --hard do, I still dislike it when I need to consider
whether --hard, --mixed or --soft.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/user-manual.txt b/Documentation/user-manual.txt
index 94799fa..4e21097 100644
--- a/Documentation/user-manual.txt
+++ b/Documentation/user-manual.txt
@@ -1408,7 +1408,7 @@ If you get stuck and decide to just give up and throw the whole mess
 away, you can always return to the pre-merge state with
 
 -------------------------------------------------
-$ git reset --hard HEAD
+$ git merge --abort
 -------------------------------------------------
 
 Or, if you've already committed the merge that you want to throw away,
-- 
cgit v0.10.2-6-g49f6


From 80f537f79c16efeb7b92b3409ede434a230b5679 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:58 +0700
Subject: doc: promote "git restore"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The new command "git restore" (together with "git switch") are added
to avoid the confusion of one-command-do-all "git checkout" for new
users. They are also helpful to avoid ambiguous context.

For these reasons, promote it everywhere possible. This includes
documentation, suggestions/advice from other commands.

One nice thing about git-restore is the ability to restore
"everything", so it can be used in "git status" advice instead of both
"git checkout" and "git reset".  The three commands suggested by "git
status" are add, rm and restore.

"git checkout" is also removed from "git help" (i.e. it's no longer
considered a commonly used command)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-clean.txt b/Documentation/git-clean.txt
index 03056da..8a31ccf 100644
--- a/Documentation/git-clean.txt
+++ b/Documentation/git-clean.txt
@@ -64,7 +64,7 @@ OPTIONS
 	directory) and $GIT_DIR/info/exclude, but do still use the ignore
 	rules given with `-e` options.  This allows removing all untracked
 	files, including build products.  This can be used (possibly in
-	conjunction with 'git reset') to create a pristine
+	conjunction with 'git restore' or 'git reset') to create a pristine
 	working directory to test a clean build.
 
 -X::
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index a85c2c2..7628193 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -359,7 +359,7 @@ When recording your own work, the contents of modified files in
 your working tree are temporarily stored to a staging area
 called the "index" with 'git add'.  A file can be
 reverted back, only in the index but not in the working tree,
-to that of the last commit with `git reset HEAD -- <file>`,
+to that of the last commit with `git restore --staged <file>`,
 which effectively reverts 'git add' and prevents the changes to
 this file from participating in the next commit.  After building
 the state to be committed incrementally with these commands,
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 0a24a56..01bfcec 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -422,7 +422,7 @@ One way to test if your MUA is set up correctly is:
 
     $ git fetch <project> master:test-apply
     $ git switch test-apply
-    $ git reset --hard
+    $ git restore --source=HEAD --staged --worktree :/
     $ git am a.patch
 
 If it does not apply correctly, there can be various reasons.
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index c25f8a9..633d71d 100644
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -29,9 +29,9 @@ This means that `git reset <paths>` is the opposite of `git add
 `git restore [--source=<tree-ish>] --staged <paths>...`.
 +
 After running `git reset <paths>` to update the index entry, you can
-use linkgit:git-checkout[1] to check the contents out of the index to
-the working tree.
-Alternatively, using linkgit:git-checkout[1] and specifying a commit, you
+use linkgit:git-restore[1] to check the contents out of the index to
+the working tree. Alternatively, using linkgit:git-restore[1]
+and specifying a commit with `--source`, you
 can copy the contents of a path out of a commit to the index and to the
 working tree in one go.
 
diff --git a/Documentation/git-revert.txt b/Documentation/git-revert.txt
index 018ecf4..9aadc36 100644
--- a/Documentation/git-revert.txt
+++ b/Documentation/git-revert.txt
@@ -26,8 +26,8 @@ effect of some earlier commits (often only a faulty one).  If you want to
 throw away all uncommitted changes in your working directory, you
 should see linkgit:git-reset[1], particularly the `--hard` option.  If
 you want to extract specific files as they were in another commit, you
-should see linkgit:git-checkout[1], specifically the `git checkout
-<commit> -- <filename>` syntax.  Take care with these alternatives as
+should see linkgit:git-restore[1], specifically the `--source`
+option. Take care with these alternatives as
 both will discard uncommitted changes in your working directory.
 
 See "Reset, restore and revert" in linkgit:git[1] for the differences
diff --git a/Documentation/gitcli.txt b/Documentation/gitcli.txt
index 225513e..1ed3ca3 100644
--- a/Documentation/gitcli.txt
+++ b/Documentation/gitcli.txt
@@ -47,8 +47,8 @@ disambiguating `--` at appropriate places.
    things:
 +
 --------------------------------
-$ git checkout -- *.c
-$ git checkout -- \*.c
+$ git restore *.c
+$ git restore \*.c
 --------------------------------
 +
 The former lets your shell expand the fileglob, and you are asking
diff --git a/Documentation/giteveryday.txt b/Documentation/giteveryday.txt
index ad455f3..1bd919f 100644
--- a/Documentation/giteveryday.txt
+++ b/Documentation/giteveryday.txt
@@ -51,8 +51,7 @@ following commands.
 
   * linkgit:git-commit[1] to advance the current branch.
 
-  * linkgit:git-reset[1] and linkgit:git-checkout[1] (with
-    pathname parameters) to undo changes.
+  * linkgit:git-restore[1] to undo changes.
 
   * linkgit:git-merge[1] to merge between local branches.
 
@@ -82,7 +81,7 @@ Create a topic branch and develop.::
 ------------
 $ git switch -c alsa-audio <1>
 $ edit/compile/test
-$ git checkout -- curses/ux_audio_oss.c <2>
+$ git restore curses/ux_audio_oss.c <2>
 $ git add curses/ux_audio_alsa.c <3>
 $ edit/compile/test
 $ git diff HEAD <4>
diff --git a/Documentation/gittutorial-2.txt b/Documentation/gittutorial-2.txt
index e0976f6..8bdb7d0 100644
--- a/Documentation/gittutorial-2.txt
+++ b/Documentation/gittutorial-2.txt
@@ -370,13 +370,13 @@ situation:
 $ git status
 On branch master
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   closing.txt
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   file.txt
 
diff --git a/Documentation/gittutorial.txt b/Documentation/gittutorial.txt
index e6ad6b5..59ef5ce 100644
--- a/Documentation/gittutorial.txt
+++ b/Documentation/gittutorial.txt
@@ -110,7 +110,7 @@ $ git status
 On branch master
 Changes to be committed:
 Your branch is up to date with 'origin/master'.
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   file1
 	modified:   file2
diff --git a/Documentation/user-manual.txt b/Documentation/user-manual.txt
index 4e21097..8bce75b 100644
--- a/Documentation/user-manual.txt
+++ b/Documentation/user-manual.txt
@@ -1446,7 +1446,7 @@ mistake, you can return the entire working tree to the last committed
 state with
 
 -------------------------------------------------
-$ git reset --hard HEAD
+$ git restore --staged --worktree :/
 -------------------------------------------------
 
 If you make a commit that you later wish you hadn't, there are two
@@ -1523,12 +1523,10 @@ Checking out an old version of a file
 
 In the process of undoing a previous bad change, you may find it
 useful to check out an older version of a particular file using
-linkgit:git-checkout[1].  We've used `git checkout` before to switch
-branches, but it has quite different behavior if it is given a path
-name: the command
+linkgit:git-restore[1]. The command
 
 -------------------------------------------------
-$ git checkout HEAD^ path/to/file
+$ git restore --source=HEAD^ path/to/file
 -------------------------------------------------
 
 replaces path/to/file by the contents it had in the commit HEAD^, and
@@ -3800,8 +3798,8 @@ use linkgit:git-tag[1] for both.
 The Workflow
 ------------
 
-High-level operations such as linkgit:git-commit[1],
-linkgit:git-checkout[1] and linkgit:git-reset[1] work by moving data
+High-level operations such as linkgit:git-commit[1] and
+linkgit:git-restore[1] work by moving data
 between the working tree, the index, and the object database.  Git
 provides low-level operations which perform each of these steps
 individually.
diff --git a/builtin/clone.c b/builtin/clone.c
index 50bde99..024eb57 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -492,7 +492,7 @@ static enum {
 static const char junk_leave_repo_msg[] =
 N_("Clone succeeded, but checkout failed.\n"
    "You can inspect what was checked out with 'git status'\n"
-   "and retry the checkout with 'git checkout -f HEAD'\n");
+   "and retry with 'git restore --source=HEAD :/'\n");
 
 static void remove_junk(void)
 {
diff --git a/builtin/commit.c b/builtin/commit.c
index f175374..fa5982c 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1676,7 +1676,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	if (commit_index_files())
 		die(_("repository has been updated, but unable to write\n"
 		      "new_index file. Check that disk is not full and quota is\n"
-		      "not exceeded, and then \"git reset HEAD\" to recover."));
+		      "not exceeded, and then \"git restore --staged :/\" to recover."));
 
 	if (git_env_bool(GIT_TEST_COMMIT_GRAPH, 0))
 		write_commit_graph_reachable(get_object_directory(), 0, 0);
diff --git a/command-list.txt b/command-list.txt
index b9eae1c..cf8dccb 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -59,7 +59,7 @@ git-cat-file                            plumbinginterrogators
 git-check-attr                          purehelpers
 git-check-ignore                        purehelpers
 git-check-mailmap                       purehelpers
-git-checkout                            mainporcelain           history
+git-checkout                            mainporcelain
 git-checkout-index                      plumbingmanipulators
 git-check-ref-format                    purehelpers
 git-cherry                              plumbinginterrogators          complete
diff --git a/t/t7508-status.sh b/t/t7508-status.sh
index e1f1129..681bc31 100755
--- a/t/t7508-status.sh
+++ b/t/t7508-status.sh
@@ -94,13 +94,13 @@ test_expect_success 'status --column' '
 #   (use "git pull" to merge the remote branch into yours)
 #
 # Changes to be committed:
-#   (use "git reset HEAD <file>..." to unstage)
+#   (use "git restore --staged <file>..." to unstage)
 #
 #	new file:   dir2/added
 #
 # Changes not staged for commit:
 #   (use "git add <file>..." to update what will be committed)
-#   (use "git checkout -- <file>..." to discard changes in working directory)
+#   (use "git restore <file>..." to discard changes in working directory)
 #
 #	modified:   dir1/modified
 #
@@ -128,13 +128,13 @@ cat >expect <<\EOF
 #   (use "git pull" to merge the remote branch into yours)
 #
 # Changes to be committed:
-#   (use "git reset HEAD <file>..." to unstage)
+#   (use "git restore --staged <file>..." to unstage)
 #
 #	new file:   dir2/added
 #
 # Changes not staged for commit:
 #   (use "git add <file>..." to update what will be committed)
-#   (use "git checkout -- <file>..." to discard changes in working directory)
+#   (use "git restore <file>..." to discard changes in working directory)
 #
 #	modified:   dir1/modified
 #
@@ -278,13 +278,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -347,13 +347,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -420,13 +420,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -484,13 +484,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -542,13 +542,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -605,13 +605,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   ../dir2/added
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   modified
 
@@ -676,13 +676,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	<GREEN>new file:   dir2/added<RESET>
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	<RED>modified:   dir1/modified<RESET>
 
@@ -802,13 +802,13 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -852,7 +852,7 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   dir1/modified
 
@@ -896,14 +896,14 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 	new file:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -956,14 +956,14 @@ and have 1 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	new file:   dir2/added
 	new file:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -1019,7 +1019,7 @@ and have 2 and 2 different commits each, respectively.
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -1068,14 +1068,14 @@ and have 2 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD^1 <file>..." to unstage)
+  (use "git restore --source=HEAD^1 --staged <file>..." to unstage)
 
 	new file:   dir2/added
 	new file:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -1123,13 +1123,13 @@ and have 2 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -1235,13 +1235,13 @@ and have 2 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
   (commit or discard the untracked or modified content in submodules)
 
 	modified:   dir1/modified
@@ -1295,13 +1295,13 @@ and have 2 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 	modified:   sm (new commits)
@@ -1379,13 +1379,13 @@ cat > expect << EOF
 ;   (use "git pull" to merge the remote branch into yours)
 ;
 ; Changes to be committed:
-;   (use "git reset HEAD <file>..." to unstage)
+;   (use "git restore --staged <file>..." to unstage)
 ;
 ;	modified:   sm
 ;
 ; Changes not staged for commit:
 ;   (use "git add <file>..." to update what will be committed)
-;   (use "git checkout -- <file>..." to discard changes in working directory)
+;   (use "git restore <file>..." to discard changes in working directory)
 ;
 ;	modified:   dir1/modified
 ;	modified:   sm (new commits)
@@ -1431,7 +1431,7 @@ and have 2 and 2 different commits each, respectively.
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -1458,13 +1458,13 @@ and have 2 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
@@ -1581,13 +1581,13 @@ and have 2 and 2 different commits each, respectively.
   (use "git pull" to merge the remote branch into yours)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   sm
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   dir1/modified
 
diff --git a/t/t7512-status-help.sh b/t/t7512-status-help.sh
index 458608c..1b9712c 100755
--- a/t/t7512-status-help.sh
+++ b/t/t7512-status-help.sh
@@ -85,7 +85,7 @@ You are currently rebasing branch '\''rebase_conflicts'\'' on '\''$ONTO'\''.
   (use "git rebase --abort" to check out the original branch)
 
 Unmerged paths:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
   (use "git add <file>..." to mark resolution)
 
 	both modified:   main.txt
@@ -110,7 +110,7 @@ You are currently rebasing branch '\''rebase_conflicts'\'' on '\''$ONTO'\''.
   (all conflicts fixed: run "git rebase --continue")
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   main.txt
 
@@ -148,7 +148,7 @@ You are currently rebasing branch '\''rebase_i_conflicts_second'\'' on '\''$ONTO
   (use "git rebase --abort" to check out the original branch)
 
 Unmerged paths:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
   (use "git add <file>..." to mark resolution)
 
 	both modified:   main.txt
@@ -176,7 +176,7 @@ You are currently rebasing branch '\''rebase_i_conflicts_second'\'' on '\''$ONTO
   (all conflicts fixed: run "git rebase --continue")
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   main.txt
 
@@ -246,7 +246,7 @@ You are currently splitting a commit while rebasing branch '\''split_commit'\''
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   main.txt
 
@@ -354,7 +354,7 @@ You are currently splitting a commit while rebasing branch '\''several_edits'\''
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   main.txt
 
@@ -453,7 +453,7 @@ You are currently splitting a commit while rebasing branch '\''several_edits'\''
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   main.txt
 
@@ -557,7 +557,7 @@ You are currently splitting a commit while rebasing branch '\''several_edits'\''
 
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
-  (use "git checkout -- <file>..." to discard changes in working directory)
+  (use "git restore <file>..." to discard changes in working directory)
 
 	modified:   main.txt
 
@@ -816,7 +816,7 @@ You are currently reverting commit $TO_REVERT.
   (use "git revert --abort" to cancel the revert operation)
 
 Unmerged paths:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
   (use "git add <file>..." to mark resolution)
 
 	both modified:   to-revert.txt
@@ -837,7 +837,7 @@ You are currently reverting commit $TO_REVERT.
   (use "git revert --abort" to cancel the revert operation)
 
 Changes to be committed:
-  (use "git reset HEAD <file>..." to unstage)
+  (use "git restore --staged <file>..." to unstage)
 
 	modified:   to-revert.txt
 
diff --git a/wt-status.c b/wt-status.c
index 445a362..19fd1ad 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -178,9 +178,15 @@ static void wt_longstatus_print_unmerged_header(struct wt_status *s)
 		return;
 	if (s->whence != FROM_COMMIT)
 		;
-	else if (!s->is_initial)
-		status_printf_ln(s, c, _("  (use \"git reset %s <file>...\" to unstage)"), s->reference);
-	else
+	else if (!s->is_initial) {
+		if (!strcmp(s->reference, "HEAD"))
+			status_printf_ln(s, c,
+					 _("  (use \"git restore --staged <file>...\" to unstage)"));
+		else
+			status_printf_ln(s, c,
+					 _("  (use \"git restore --source=%s --staged <file>...\" to unstage)"),
+					 s->reference);
+	} else
 		status_printf_ln(s, c, _("  (use \"git rm --cached <file>...\" to unstage)"));
 
 	if (!both_deleted) {
@@ -205,9 +211,15 @@ static void wt_longstatus_print_cached_header(struct wt_status *s)
 		return;
 	if (s->whence != FROM_COMMIT)
 		; /* NEEDSWORK: use "git reset --unresolve"??? */
-	else if (!s->is_initial)
-		status_printf_ln(s, c, _("  (use \"git reset %s <file>...\" to unstage)"), s->reference);
-	else
+	else if (!s->is_initial) {
+		if (!strcmp(s->reference, "HEAD"))
+			status_printf_ln(s, c
+					 , _("  (use \"git restore --staged <file>...\" to unstage)"));
+		else
+			status_printf_ln(s, c,
+					 _("  (use \"git restore --source=%s --staged <file>...\" to unstage)"),
+					 s->reference);
+	} else
 		status_printf_ln(s, c, _("  (use \"git rm --cached <file>...\" to unstage)"));
 	status_printf_ln(s, c, "%s", "");
 }
@@ -225,7 +237,7 @@ static void wt_longstatus_print_dirty_header(struct wt_status *s,
 		status_printf_ln(s, c, _("  (use \"git add <file>...\" to update what will be committed)"));
 	else
 		status_printf_ln(s, c, _("  (use \"git add/rm <file>...\" to update what will be committed)"));
-	status_printf_ln(s, c, _("  (use \"git checkout -- <file>...\" to discard changes in working directory)"));
+	status_printf_ln(s, c, _("  (use \"git restore <file>...\" to discard changes in working directory)"));
 	if (has_dirty_submodules)
 		status_printf_ln(s, c, _("  (commit or discard the untracked or modified content in submodules)"));
 	status_printf_ln(s, c, "%s", "");
-- 
cgit v0.10.2-6-g49f6


From 12358755949084392b1112cfb5cb4feb9935331f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:45:59 +0700
Subject: help: move git-diff and git-reset to different groups
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The third column in command-list.txt determines what group a common
command is printed in 'git help'.

"git reset" is currently in the "work on the current change (see also:
git help everyday)" group. While it's true that "git reset" can
manipulate the index and can be in this group, its unique
functionality is resetting HEAD, which should be the "grow, mark,
tweak history" group.

Moving it there will also avoid the confusion because both 'restore'
and 'reset' are in the same group, next to each other.

While looking at the 'group, mark, tweak history', I realize "git
diff" should not be there. All the commands in this group is about
_changing_ the commit history while "git diff" is a read-only
operation. It fits better in the "examine the history and state" group
(especially when "git status", its close friend, is already there).

This is what we have after the reorganization:

    work on the current change (see also: git help everyday)
       add       Add file contents to the index
       mv        Move or rename a file, a directory, or a symlink
       restore   Restore working tree files
       rm        Remove files from the working tree and from the index

    examine the history and state (see also: git help revisions)
       bisect    Use binary search to find the commit that introduced a bug
       diff      Show changes between commits, commit and working tree, etc
       grep      Print lines matching a pattern
       log       Show commit logs
       show      Show various types of objects
       status    Show the working tree status

    grow, mark and tweak your common history
       branch    List, create, or delete branches
       commit    Record changes to the repository
       merge     Join two or more development histories together
       rebase    Reapply commits on top of another base tip
       reset     Reset current HEAD to the specified state
       switch    Switch branches
       tag       Create, list, delete or verify a tag object signed with GPG

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/command-list.txt b/command-list.txt
index cf8dccb..a9ac72b 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -81,7 +81,7 @@ git-cvsimport                           foreignscminterface
 git-cvsserver                           foreignscminterface
 git-daemon                              synchingrepositories
 git-describe                            mainporcelain
-git-diff                                mainporcelain           history
+git-diff                                mainporcelain           info
 git-diff-files                          plumbinginterrogators
 git-diff-index                          plumbinginterrogators
 git-diff-tree                           plumbinginterrogators
@@ -150,7 +150,7 @@ git-repack                              ancillarymanipulators           complete
 git-replace                             ancillarymanipulators           complete
 git-request-pull                        foreignscminterface             complete
 git-rerere                              ancillaryinterrogators
-git-reset                               mainporcelain           worktree
+git-reset                               mainporcelain           history
 git-restore                             mainporcelain           worktree
 git-revert                              mainporcelain
 git-rev-list                            plumbinginterrogators
-- 
cgit v0.10.2-6-g49f6


From 4e43b7ff1ea4b6f16b93a432b6718e9ab38749bd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 25 Apr 2019 16:46:00 +0700
Subject: Declare both git-switch and git-restore experimental
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

These two commands are basically redesigned git-checkout. We will not
have that many opportunities to redo (because we run out of verbs, and
that would also increase maintenance cost).

To play it safe, let's declare the two commands experimental in one or
two releases. If there is a serious flaw in the UI, we could still fix
it. If everything goes well and nobody complains loudly, we can remove
the experimental status by reverting this patch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-restore.txt b/Documentation/git-restore.txt
index b608f3f..d90093f 100644
--- a/Documentation/git-restore.txt
+++ b/Documentation/git-restore.txt
@@ -28,6 +28,8 @@ commit as the restore source.
 See "Reset, restore and revert" in linkgit:git[1] for the differences
 between the three commands.
 
+THIS COMMAND IS EXPERIMENTAL. THE BEHAVIOR MAY CHANGE.
+
 OPTIONS
 -------
 -s <tree>::
diff --git a/Documentation/git-switch.txt b/Documentation/git-switch.txt
index f15e5bd..1979003 100644
--- a/Documentation/git-switch.txt
+++ b/Documentation/git-switch.txt
@@ -29,6 +29,8 @@ Switching branches does not require a clean index and working tree
 however if the operation leads to loss of local changes, unless told
 otherwise with `--discard-changes` or `--merge`.
 
+THIS COMMAND IS EXPERIMENTAL. THE BEHAVIOR MAY CHANGE.
+
 OPTIONS
 -------
 <branch>::
-- 
cgit v0.10.2-6-g49f6


From bcba406532725fcdf17d5a3d9c6585e8fc879021 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 20 Jun 2019 16:55:20 +0700
Subject: t2027: use test_must_be_empty
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t2070-restore.sh b/t/t2070-restore.sh
index 73ea13e..2650df1 100755
--- a/t/t2070-restore.sh
+++ b/t/t2070-restore.sh
@@ -90,9 +90,8 @@ test_expect_success 'restore --ignore-unmerged ignores unmerged entries' '
 
 		git restore --ignore-unmerged --quiet . >output 2>&1 &&
 		git diff common >diff-output &&
-		: >empty &&
-		test_cmp empty output &&
-		test_cmp empty diff-output
+		test_must_be_empty output &&
+		test_must_be_empty diff-output
 	)
 '
 
-- 
cgit v0.10.2-6-g49f6


From d16dc428b47837cebd231de1fad76d9c307f34b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 20 Jun 2019 16:55:21 +0700
Subject: switch: allow to switch in the middle of bisect
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

In c45f0f525d (switch: reject if some operation is in progress,
2019-03-29), a check is added to prevent switching when some operation
is in progress. The reason is it's often not safe to do so.

This is true for merge, am, rebase, cherry-pick and revert, but not so
much for bisect because bisecting is basically jumping/switching between
a bunch of commits to pin point the first bad one. git-bisect suggests
the next commit to test, but it's not wrong for the user to test a
different commit because git-bisect cannot have the knowledge to know
better.

For this reason, allow to switch when bisecting (*). I considered if we
should still prevent switching by default and allow it with
--ignore-in-progress. But I don't think the prevention really adds
anything much.

If the user switches away by mistake, since we print the previous HEAD
value, even if they don't know about the "-" shortcut, switching back is
still possible.

The warning will be printed on every switch while bisect is still
ongoing, not the first time you switch away from bisect's suggested
commit, so it could become a bit annoying.

(*) of course when it's safe to do so, i.e. no loss of local changes and
stuff.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/checkout.c b/builtin/checkout.c
index bed79ae..f884d27 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1326,9 +1326,7 @@ static void die_if_some_operation_in_progress(void)
 		      "Consider \"git revert --quit\" "
 		      "or \"git worktree add\"."));
 	if (state.bisect_in_progress)
-		die(_("cannot switch branch while bisecting\n"
-		      "Consider \"git bisect reset HEAD\" "
-		      "or \"git worktree add\"."));
+		warning(_("you are switching branch while bisecting"));
 }
 
 static int checkout_branch(struct checkout_opts *opts,
-- 
cgit v0.10.2-6-g49f6


From 97ed685701a6df0273f7d29fd5bc0a0658a63cad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?=
 <pclouds@gmail.com>
Date: Thu, 20 Jun 2019 16:55:22 +0700
Subject: completion: disable dwim on "git switch -d"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Even though dwim is enabled by default, it will never be done when
--detached is specified. If you force "-d --guess" you will get an error
because --guess then implies -c which cannot be used with -d. So we can
disable dwim in "switch -d". It makes the completion list in this case a
bit shorter.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 58d18d4..656e497 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -2183,6 +2183,10 @@ _git_switch ()
 		fi
 		if [ -z "$(__git_find_on_cmdline "-d --detach")" ]; then
 			only_local_ref=y
+		else
+			# --guess --detach is invalid combination, no
+			# dwim will be done when --detach is specified
+			track_opt=
 		fi
 		if [ $only_local_ref = y -a -z "$track_opt" ]; then
 			__gitcomp_direct "$(__git_heads "" "$cur" " ")"
-- 
cgit v0.10.2-6-g49f6