Merge branch 'ds/rebase-update-ref'

"git rebase -i" learns to update branches whose tip appear in the
rebased range with "--update-refs" option.
source: <pull.1247.v5.git.1658255624.gitgitgadget@gmail.com>

* ds/rebase-update-ref:
  sequencer: notify user of --update-refs activity
  sequencer: ignore HEAD ref under --update-refs
  rebase: add rebase.updateRefs config option
  sequencer: rewrite update-refs as user edits todo list
  rebase: update refs from 'update-ref' commands
  rebase: add --update-refs option
  sequencer: add update-ref command
  sequencer: define array with enum values
  rebase-interactive: update 'merge' description
  branch: consider refs under 'update-refs'
  t2407: test branches currently using apply backend
  t2407: test bisect and rebase as black-boxes

3 files changed, 365 insertions, 26 deletions

diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index ec6b9b1..b575413 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -207,3 +207,18 @@ check_reworded_commits () {
 		>reword-log &&
 	test_cmp reword-expected reword-log
 }
+
+# usage: set_replace_editor <file>
+#
+# Replace the todo file with the exact contents of the given file.
+set_replace_editor () {
+	cat >script <<-\EOF &&
+	cat FILENAME >"$1"
+
+	echo 'rebase -i script after editing:'
+	cat "$1"
+	EOF
+
+	sed -e "s/FILENAME/$1/g" <script | write_script fake-editor.sh &&
+	test_set_editor "$(pwd)/fake-editor.sh"
+}
diff --git a/t/t2407-worktree-heads.sh b/t/t2407-worktree-heads.sh
index b6be42f..50815ac 100755
--- a/t/t2407-worktree-heads.sh
+++ b/t/t2407-worktree-heads.sh
@@ -7,13 +7,18 @@ TEST_PASSES_SANITIZE_LEAK=true
 
 test_expect_success 'setup' '
 	test_commit init &&
-	git branch -f fake-1 &&
-	git branch -f fake-2 &&
 
 	for i in 1 2 3 4
 	do
+		git checkout -b conflict-$i &&
+		echo "not I" >$i.t &&
+		git add $i.t &&
+		git commit -m "will conflict" &&
+
+		git checkout - &&
 		test_commit $i &&
 		git branch wt-$i &&
+		git branch fake-$i &&
 		git worktree add wt-$i wt-$i || return 1
 	done &&
 
@@ -44,26 +49,50 @@ test_expect_success 'refuse to overwrite: checked out in worktree' '
 	done
 '
 
-test_expect_success 'refuse to overwrite: worktree in bisect' '
-	test_when_finished rm -rf .git/worktrees/wt-*/BISECT_* &&
+test_expect_success !SANITIZE_LEAK 'refuse to overwrite: worktree in bisect' '
+	test_when_finished git -C wt-4 bisect reset &&
 
-	touch .git/worktrees/wt-4/BISECT_LOG &&
-	echo refs/heads/fake-2 >.git/worktrees/wt-4/BISECT_START &&
+	# Set up a bisect so HEAD no longer points to wt-4.
+	git -C wt-4 bisect start &&
+	git -C wt-4 bisect bad wt-4 &&
+	git -C wt-4 bisect good wt-1 &&
 
-	test_must_fail git branch -f fake-2 HEAD 2>err &&
-	grep "cannot force update the branch '\''fake-2'\'' checked out at.*wt-4" err
+	test_must_fail git branch -f wt-4 HEAD 2>err &&
+	grep "cannot force update the branch '\''wt-4'\'' checked out at.*wt-4" err
 '
 
-test_expect_success 'refuse to overwrite: worktree in rebase' '
-	test_when_finished rm -rf .git/worktrees/wt-*/rebase-merge &&
+test_expect_success !SANITIZE_LEAK 'refuse to overwrite: worktree in rebase (apply)' '
+	test_when_finished git -C wt-2 rebase --abort &&
 
-	mkdir -p .git/worktrees/wt-3/rebase-merge &&
-	touch .git/worktrees/wt-3/rebase-merge/interactive &&
-	echo refs/heads/fake-1 >.git/worktrees/wt-3/rebase-merge/head-name &&
-	echo refs/heads/fake-2 >.git/worktrees/wt-3/rebase-merge/onto &&
+	# This will fail part-way through due to a conflict.
+	test_must_fail git -C wt-2 rebase --apply conflict-2 &&
+
+	test_must_fail git branch -f wt-2 HEAD 2>err &&
+	grep "cannot force update the branch '\''wt-2'\'' checked out at.*wt-2" err
+'
+
+test_expect_success !SANITIZE_LEAK 'refuse to overwrite: worktree in rebase (merge)' '
+	test_when_finished git -C wt-2 rebase --abort &&
 
-	test_must_fail git branch -f fake-1 HEAD 2>err &&
-	grep "cannot force update the branch '\''fake-1'\'' checked out at.*wt-3" err
+	# This will fail part-way through due to a conflict.
+	test_must_fail git -C wt-2 rebase conflict-2 &&
+
+	test_must_fail git branch -f wt-2 HEAD 2>err &&
+	grep "cannot force update the branch '\''wt-2'\'' checked out at.*wt-2" err
+'
+
+test_expect_success !SANITIZE_LEAK 'refuse to overwrite: worktree in rebase with --update-refs' '
+	test_when_finished git -C wt-3 rebase --abort &&
+
+	git branch -f can-be-updated wt-3 &&
+	test_must_fail git -C wt-3 rebase --update-refs conflict-3 &&
+
+	for i in 3 4
+	do
+		test_must_fail git branch -f can-be-updated HEAD 2>err &&
+		grep "cannot force update the branch '\''can-be-updated'\'' checked out at.*wt-3" err ||
+			return 1
+	done
 '
 
 test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: checked out' '
@@ -77,24 +106,24 @@ test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: checked out' '
 '
 
 test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: worktree in bisect' '
-	test_when_finished rm -rf .git/worktrees/wt-*/BISECT_* &&
+	test_when_finished git -C wt-4 bisect reset &&
 
-	touch .git/worktrees/wt-4/BISECT_LOG &&
-	echo refs/heads/fake-2 >.git/worktrees/wt-4/BISECT_START &&
+	# Set up a bisect so HEAD no longer points to wt-4.
+	git -C wt-4 bisect start &&
+	git -C wt-4 bisect bad wt-4 &&
+	git -C wt-4 bisect good wt-1 &&
 
-	test_must_fail git fetch server +refs/heads/fake-2:refs/heads/fake-2 2>err &&
+	test_must_fail git fetch server +refs/heads/wt-4:refs/heads/wt-4 2>err &&
 	grep "refusing to fetch into branch" err
 '
 
 test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: worktree in rebase' '
-	test_when_finished rm -rf .git/worktrees/wt-*/rebase-merge &&
+	test_when_finished git -C wt-3 rebase --abort &&
 
-	mkdir -p .git/worktrees/wt-4/rebase-merge &&
-	touch .git/worktrees/wt-4/rebase-merge/interactive &&
-	echo refs/heads/fake-1 >.git/worktrees/wt-4/rebase-merge/head-name &&
-	echo refs/heads/fake-2 >.git/worktrees/wt-4/rebase-merge/onto &&
+	# This will fail part-way through due to a conflict.
+	test_must_fail git -C wt-3 rebase conflict-3 &&
 
-	test_must_fail git fetch server +refs/heads/fake-1:refs/heads/fake-1 2>err &&
+	test_must_fail git fetch server +refs/heads/wt-3:refs/heads/wt-3 2>err &&
 	grep "refusing to fetch into branch" err
 '
 
@@ -126,4 +155,26 @@ test_expect_success 'refuse to overwrite when in error states' '
 	done
 '
 
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+test_expect_success !SANITIZE_LEAK 'refuse to overwrite during rebase with --update-refs' '
+	git commit --fixup HEAD~2 --allow-empty &&
+	(
+		set_cat_todo_editor &&
+		test_must_fail git rebase -i --update-refs HEAD~3 >todo &&
+		! grep "update-refs" todo
+	) &&
+	git branch -f allow-update HEAD~2 &&
+	(
+		set_cat_todo_editor &&
+		test_must_fail git rebase -i --update-refs HEAD~3 >todo &&
+		grep "update-ref refs/heads/allow-update" todo
+	)
+'
+
+# This must be the last test in this file
+test_expect_success '$EDITOR and friends are unchanged' '
+	test_editor_unchanged
+'
+
 test_done
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index f31afd4..688b01e 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1743,6 +1743,279 @@ test_expect_success 'ORIG_HEAD is updated correctly' '
 	test_cmp_rev ORIG_HEAD test-orig-head@{1}
 '
 
+test_expect_success '--update-refs adds label and update-ref commands' '
+	git checkout -b update-refs no-conflict-branch &&
+	git branch -f base HEAD~4 &&
+	git branch -f first HEAD~3 &&
+	git branch -f second HEAD~3 &&
+	git branch -f third HEAD~1 &&
+	git commit --allow-empty --fixup=third &&
+	git branch -f is-not-reordered &&
+	git commit --allow-empty --fixup=HEAD~4 &&
+	git branch -f shared-tip &&
+	(
+		set_cat_todo_editor &&
+
+		cat >expect <<-EOF &&
+		pick $(git log -1 --format=%h J) J
+		fixup $(git log -1 --format=%h update-refs) fixup! J # empty
+		update-ref refs/heads/second
+		update-ref refs/heads/first
+		pick $(git log -1 --format=%h K) K
+		pick $(git log -1 --format=%h L) L
+		fixup $(git log -1 --format=%h is-not-reordered) fixup! L # empty
+		update-ref refs/heads/third
+		pick $(git log -1 --format=%h M) M
+		update-ref refs/heads/no-conflict-branch
+		update-ref refs/heads/is-not-reordered
+		update-ref refs/heads/shared-tip
+		EOF
+
+		test_must_fail git rebase -i --autosquash --update-refs primary >todo &&
+		test_cmp expect todo &&
+
+		test_must_fail git -c rebase.autosquash=true \
+				   -c rebase.updaterefs=true \
+				   rebase -i primary >todo &&
+
+		test_cmp expect todo
+	)
+'
+
+test_expect_success '--update-refs adds commands with --rebase-merges' '
+	git checkout -b update-refs-with-merge no-conflict-branch &&
+	git branch -f base HEAD~4 &&
+	git branch -f first HEAD~3 &&
+	git branch -f second HEAD~3 &&
+	git branch -f third HEAD~1 &&
+	git merge -m merge branch2 &&
+	git branch -f merge-branch &&
+	git commit --fixup=third --allow-empty &&
+	(
+		set_cat_todo_editor &&
+
+		cat >expect <<-EOF &&
+		label onto
+		reset onto
+		pick $(git log -1 --format=%h branch2~1) F
+		pick $(git log -1 --format=%h branch2) I
+		update-ref refs/heads/branch2
+		label merge
+		reset onto
+		pick $(git log -1 --format=%h refs/heads/second) J
+		update-ref refs/heads/second
+		update-ref refs/heads/first
+		pick $(git log -1 --format=%h refs/heads/third~1) K
+		pick $(git log -1 --format=%h refs/heads/third) L
+		fixup $(git log -1 --format=%h update-refs-with-merge) fixup! L # empty
+		update-ref refs/heads/third
+		pick $(git log -1 --format=%h HEAD~2) M
+		update-ref refs/heads/no-conflict-branch
+		merge -C $(git log -1 --format=%h HEAD~1) merge # merge
+		update-ref refs/heads/merge-branch
+		EOF
+
+		test_must_fail git rebase -i --autosquash \
+				   --rebase-merges=rebase-cousins \
+				   --update-refs primary >todo &&
+
+		test_cmp expect todo &&
+
+		test_must_fail git -c rebase.autosquash=true \
+				   -c rebase.updaterefs=true \
+				   rebase -i \
+				   --rebase-merges=rebase-cousins \
+				   primary >todo &&
+
+		test_cmp expect todo
+	)
+'
+
+test_expect_success '--update-refs updates refs correctly' '
+	git checkout -B update-refs no-conflict-branch &&
+	git branch -f base HEAD~4 &&
+	git branch -f first HEAD~3 &&
+	git branch -f second HEAD~3 &&
+	git branch -f third HEAD~1 &&
+	test_commit extra2 fileX &&
+	git commit --amend --fixup=L &&
+
+	git rebase -i --autosquash --update-refs primary 2>err &&
+
+	test_cmp_rev HEAD~3 refs/heads/first &&
+	test_cmp_rev HEAD~3 refs/heads/second &&
+	test_cmp_rev HEAD~1 refs/heads/third &&
+	test_cmp_rev HEAD refs/heads/no-conflict-branch &&
+
+	cat >expect <<-\EOF &&
+	Successfully rebased and updated refs/heads/update-refs.
+	Updated the following refs with --update-refs:
+		refs/heads/first
+		refs/heads/no-conflict-branch
+		refs/heads/second
+		refs/heads/third
+	EOF
+
+	# Clear "Rebasing (X/Y)" progress lines and drop leading tabs.
+	sed -e "s/Rebasing.*Successfully/Successfully/g" -e "s/^\t//g" \
+		<err >err.trimmed &&
+	test_cmp expect err.trimmed
+'
+
+test_expect_success 'respect user edits to update-ref steps' '
+	git checkout -B update-refs-break no-conflict-branch &&
+	git branch -f base HEAD~4 &&
+	git branch -f first HEAD~3 &&
+	git branch -f second HEAD~3 &&
+	git branch -f third HEAD~1 &&
+	git branch -f unseen base &&
+
+	# First, we will add breaks to the expected todo file
+	cat >fake-todo-1 <<-EOF &&
+	pick $(git rev-parse HEAD~3)
+	break
+	update-ref refs/heads/second
+	update-ref refs/heads/first
+
+	pick $(git rev-parse HEAD~2)
+	pick $(git rev-parse HEAD~1)
+	update-ref refs/heads/third
+
+	pick $(git rev-parse HEAD)
+	update-ref refs/heads/no-conflict-branch
+	EOF
+
+	# Second, we will drop some update-refs commands (and move one)
+	cat >fake-todo-2 <<-EOF &&
+	update-ref refs/heads/second
+
+	pick $(git rev-parse HEAD~2)
+	update-ref refs/heads/third
+	pick $(git rev-parse HEAD~1)
+	break
+
+	pick $(git rev-parse HEAD)
+	EOF
+
+	# Third, we will:
+	# * insert a new one (new-branch),
+	# * re-add an old one (first), and
+	# * add a second instance of a previously-stored one (second)
+	cat >fake-todo-3 <<-EOF &&
+	update-ref refs/heads/unseen
+	update-ref refs/heads/new-branch
+	pick $(git rev-parse HEAD)
+	update-ref refs/heads/first
+	update-ref refs/heads/second
+	EOF
+
+	(
+		set_replace_editor fake-todo-1 &&
+		git rebase -i --update-refs primary &&
+
+		# These branches are currently locked.
+		for b in first second third no-conflict-branch
+		do
+			test_must_fail git branch -f $b base || return 1
+		done &&
+
+		set_replace_editor fake-todo-2 &&
+		git rebase --edit-todo &&
+
+		# These branches are currently locked.
+		for b in second third
+		do
+			test_must_fail git branch -f $b base || return 1
+		done &&
+
+		# These branches are currently unlocked for checkout.
+		for b in first no-conflict-branch
+		do
+			git worktree add wt-$b $b &&
+			git worktree remove wt-$b || return 1
+		done &&
+
+		git rebase --continue &&
+
+		set_replace_editor fake-todo-3 &&
+		git rebase --edit-todo &&
+
+		# These branches are currently locked.
+		for b in second third first unseen
+		do
+			test_must_fail git branch -f $b base || return 1
+		done &&
+
+		# These branches are currently unlocked for checkout.
+		for b in no-conflict-branch
+		do
+			git worktree add wt-$b $b &&
+			git worktree remove wt-$b || return 1
+		done &&
+
+		git rebase --continue
+	) &&
+
+	test_cmp_rev HEAD~2 refs/heads/third &&
+	test_cmp_rev HEAD~1 refs/heads/unseen &&
+	test_cmp_rev HEAD~1 refs/heads/new-branch &&
+	test_cmp_rev HEAD refs/heads/first &&
+	test_cmp_rev HEAD refs/heads/second &&
+	test_cmp_rev HEAD refs/heads/no-conflict-branch
+'
+
+test_expect_success '--update-refs: check failed ref update' '
+	git checkout -B update-refs-error no-conflict-branch &&
+	git branch -f base HEAD~4 &&
+	git branch -f first HEAD~3 &&
+	git branch -f second HEAD~2 &&
+	git branch -f third HEAD~1 &&
+
+	cat >fake-todo <<-EOF &&
+	pick $(git rev-parse HEAD~3)
+	break
+	update-ref refs/heads/first
+
+	pick $(git rev-parse HEAD~2)
+	update-ref refs/heads/second
+
+	pick $(git rev-parse HEAD~1)
+	update-ref refs/heads/third
+
+	pick $(git rev-parse HEAD)
+	update-ref refs/heads/no-conflict-branch
+	EOF
+
+	(
+		set_replace_editor fake-todo &&
+		git rebase -i --update-refs base
+	) &&
+
+	# At this point, the values of first, second, and third are
+	# recorded in the update-refs file. We will force-update the
+	# "second" ref, but "git branch -f" will not work because of
+	# the lock in the update-refs file.
+	git rev-parse third >.git/refs/heads/second &&
+
+	test_must_fail git rebase --continue 2>err &&
+	grep "update_ref failed for ref '\''refs/heads/second'\''" err &&
+
+	cat >expect <<-\EOF &&
+	Updated the following refs with --update-refs:
+		refs/heads/first
+		refs/heads/no-conflict-branch
+		refs/heads/third
+	Failed to update the following refs with --update-refs:
+		refs/heads/second
+	EOF
+
+	# Clear "Rebasing (X/Y)" progress lines and drop leading tabs.
+	tail -n 6 err >err.last &&
+	sed -e "s/Rebasing.*Successfully/Successfully/g" -e "s/^\t//g" \
+		<err.last >err.trimmed &&
+	test_cmp expect err.trimmed
+'
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged