Merge branch 'es/worktree-add'

Update to the "linked checkout" in 2.5.0-rc1.

Instead of "checkout --to" that does not do what "checkout"
normally does, move the functionality to "git worktree add".

* es/worktree-add: (24 commits)
  Revert "checkout: retire --ignore-other-worktrees in favor of --force"
  checkout: retire --ignore-other-worktrees in favor of --force
  worktree: add: auto-vivify new branch when <branch> is omitted
  worktree: add: make -b/-B default to HEAD when <branch> is omitted
  worktree: extract basename computation to new function
  checkout: require worktree unconditionally
  checkout: retire --to option
  tests: worktree: retrofit "checkout --to" tests for "worktree add"
  worktree: add -b/-B options
  worktree: add --detach option
  worktree: add --force option
  worktree: introduce "add" command
  checkout: drop 'checkout_opts' dependency from prepare_linked_checkout
  checkout: make --to unconditionally verbose
  checkout: prepare_linked_checkout: drop now-unused 'new' argument
  checkout: relocate --to's "no branch specified" check
  checkout: fix bug with --to and relative HEAD
  Documentation/git-worktree: add EXAMPLES section
  Documentation/git-worktree: add high-level 'lock' overview
  Documentation/git-worktree: split technical info from general description
  ...

1 files changed, 0 insertions, 72 deletions

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 2df6d0d..63b739c 100644
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -229,13 +229,6 @@ This means that you can use `git checkout -p` to selectively discard
 edits from your current working tree. See the ``Interactive Mode''
 section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
 
---to=<path>::
-	Check out a branch in a separate working directory at
-	`<path>`. A new working directory is linked to the current
-	repository, sharing everything except working directory
-	specific files such as HEAD, index... See "MULTIPLE WORKING
-	TREES" section for more information.
-
 --ignore-other-worktrees::
 	`git checkout` refuses when the wanted ref is already checked
 	out by another worktree. This option makes it check the ref
@@ -405,71 +398,6 @@ $ git reflog -2 HEAD # or
 $ git log -g -2 HEAD
 ------------
 
-MULTIPLE WORKING TREES
-----------------------
-
-A git repository can support multiple working trees, allowing you to check
-out more than one branch at a time.  With `git checkout --to` a new working
-tree is associated with the repository.  This new working tree is called a
-"linked working tree" as opposed to the "main working tree" prepared by "git
-init" or "git clone".  A repository has one main working tree (if it's not a
-bare repository) and zero or more linked working trees.
-
-Each linked working tree has a private sub-directory in the repository's
-$GIT_DIR/worktrees directory.  The private sub-directory's name is usually
-the base name of the linked working tree's path, possibly appended with a
-number to make it unique.  For example, when `$GIT_DIR=/path/main/.git` the
-command `git checkout --to /path/other/test-next next` creates the linked
-working tree in `/path/other/test-next` and also creates a
-`$GIT_DIR/worktrees/test-next` directory (or `$GIT_DIR/worktrees/test-next1`
-if `test-next` is already taken).
-
-Within a linked working tree, $GIT_DIR is set to point to this private
-directory (e.g. `/path/main/.git/worktrees/test-next` in the example) and
-$GIT_COMMON_DIR is set to point back to the main working tree's $GIT_DIR
-(e.g. `/path/main/.git`). These settings are made in a `.git` file located at
-the top directory of the linked working tree.
-
-Path resolution via `git rev-parse --git-path` uses either
-$GIT_DIR or $GIT_COMMON_DIR depending on the path. For example, in the
-linked working tree `git rev-parse --git-path HEAD` returns
-`/path/main/.git/worktrees/test-next/HEAD` (not
-`/path/other/test-next/.git/HEAD` or `/path/main/.git/HEAD`) while `git
-rev-parse --git-path refs/heads/master` uses
-$GIT_COMMON_DIR and returns `/path/main/.git/refs/heads/master`,
-since refs are shared across all working trees.
-
-See linkgit:gitrepository-layout[5] for more information. The rule of
-thumb is do not make any assumption about whether a path belongs to
-$GIT_DIR or $GIT_COMMON_DIR when you need to directly access something
-inside $GIT_DIR. Use `git rev-parse --git-path` to get the final path.
-
-When you are done with a linked working tree you can simply delete it.
-The working tree's entry in the repository's $GIT_DIR/worktrees
-directory will eventually be removed automatically (see
-`gc.pruneworktreesexpire` in linkgit::git-config[1]), or you can run
-`git prune --worktrees` in the main or any linked working tree to
-clean up any stale entries in $GIT_DIR/worktrees.
-
-If you move a linked working directory to another file system, or
-within a file system that does not support hard links, you need to run
-at least one git command inside the linked working directory
-(e.g. `git status`) in order to update its entry in $GIT_DIR/worktrees
-so that it does not get automatically removed.
-
-To prevent a $GIT_DIR/worktrees entry from from being pruned (which
-can be useful in some situations, such as when the
-entry's working tree is stored on a portable device), add a file named
-'locked' to the entry's directory. The file contains the reason in
-plain text. For example, if a linked working tree's `.git` file points
-to `/path/main/.git/worktrees/test-next` then a file named
-`/path/main/.git/worktrees/test-next/locked` will prevent the
-`test-next` entry from being pruned.  See
-linkgit:gitrepository-layout[5] for details.
-
-Multiple checkout support for submodules is incomplete. It is NOT
-recommended to make multiple checkouts of a superproject.
-
 EXAMPLES
 --------