1 files changed, 85 insertions, 5 deletions

diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index c7ec1c7520..98b6c8ac34 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -201,8 +201,8 @@ test_expect_success 'git branch -M baz bam should succeed when baz is checked ou
 
 test_expect_success 'git branch -M baz bam should add entries to .git/logs/HEAD' '
 	msg="Branch: renamed refs/heads/baz to refs/heads/bam" &&
-	grep " 0\{40\}.*$msg$" .git/logs/HEAD &&
-	grep "^0\{40\}.*$msg$" .git/logs/HEAD
+	grep " $ZERO_OID.*$msg$" .git/logs/HEAD &&
+	grep "^$ZERO_OID.*$msg$" .git/logs/HEAD
 '
 
 test_expect_success 'git branch -M should leave orphaned HEAD alone' '
@@ -239,15 +239,34 @@ test_expect_success 'git branch -M baz bam should succeed when baz is checked ou
 	git worktree prune
 '
 
+test_expect_success 'git branch -M fails if updating any linked working tree fails' '
+	git worktree add -b baz bazdir1 &&
+	git worktree add -f bazdir2 baz &&
+	touch .git/worktrees/bazdir1/HEAD.lock &&
+	test_must_fail git branch -M baz bam &&
+	test $(git -C bazdir2 rev-parse --abbrev-ref HEAD) = bam &&
+	git branch -M bam baz &&
+	rm .git/worktrees/bazdir1/HEAD.lock &&
+	touch .git/worktrees/bazdir2/HEAD.lock &&
+	test_must_fail git branch -M baz bam &&
+	test $(git -C bazdir1 rev-parse --abbrev-ref HEAD) = bam &&
+	rm -rf bazdir1 bazdir2 &&
+	git worktree prune
+'
+
 test_expect_success 'git branch -M baz bam should succeed within a worktree in which baz is checked out' '
 	git checkout -b baz &&
 	git worktree add -f bazdir baz &&
 	(
 		cd bazdir &&
 		git branch -M baz bam &&
-		test $(git rev-parse --abbrev-ref HEAD) = bam
+		echo bam >expect &&
+		git rev-parse --abbrev-ref HEAD >actual &&
+		test_cmp expect actual
 	) &&
-	test $(git rev-parse --abbrev-ref HEAD) = bam &&
+	echo bam >expect &&
+	git rev-parse --abbrev-ref HEAD >actual &&
+	test_cmp expect actual &&
 	rm -r bazdir &&
 	git worktree prune
 '
@@ -268,6 +287,67 @@ test_expect_success 'git branch -M topic topic should work when main is checked
 	git branch -M topic topic
 '
 
+test_expect_success 'git branch -M and -C fail on detached HEAD' '
+	git checkout HEAD^{} &&
+	test_when_finished git checkout - &&
+	echo "fatal: cannot rename the current branch while not on any." >expect &&
+	test_must_fail git branch -M must-fail 2>err &&
+	test_cmp expect err &&
+	echo "fatal: cannot copy the current branch while not on any." >expect &&
+	test_must_fail git branch -C must-fail 2>err &&
+	test_cmp expect err
+'
+
+test_expect_success 'git branch -m should work with orphan branches' '
+	test_when_finished git checkout - &&
+	test_when_finished git worktree remove -f wt &&
+	git worktree add wt --detach &&
+	# rename orphan in another worktreee
+	git -C wt checkout --orphan orphan-foo-wt &&
+	git branch -m orphan-foo-wt orphan-bar-wt &&
+	test orphan-bar-wt=$(git -C orphan-worktree branch --show-current) &&
+	# rename orphan in the current worktree
+	git checkout --orphan orphan-foo &&
+	git branch -m orphan-foo orphan-bar &&
+	test orphan-bar=$(git branch --show-current)
+'
+
+test_expect_success 'git branch -d on orphan HEAD (merged)' '
+	test_when_finished git checkout main &&
+	git checkout --orphan orphan &&
+	test_when_finished "rm -rf .git/objects/commit-graph*" &&
+	git commit-graph write --reachable &&
+	git branch --track to-delete main &&
+	git branch -d to-delete
+'
+
+test_expect_success 'git branch -d on orphan HEAD (merged, graph)' '
+	test_when_finished git checkout main &&
+	git checkout --orphan orphan &&
+	git branch --track to-delete main &&
+	git branch -d to-delete
+'
+
+test_expect_success 'git branch -d on orphan HEAD (unmerged)' '
+	test_when_finished git checkout main &&
+	git checkout --orphan orphan &&
+	test_when_finished "git branch -D to-delete" &&
+	git branch to-delete main &&
+	test_must_fail git branch -d to-delete 2>err &&
+	grep "not fully merged" err
+'
+
+test_expect_success 'git branch -d on orphan HEAD (unmerged, graph)' '
+	test_when_finished git checkout main &&
+	git checkout --orphan orphan &&
+	test_when_finished "git branch -D to-delete" &&
+	git branch to-delete main &&
+	test_when_finished "rm -rf .git/objects/commit-graph*" &&
+	git commit-graph write --reachable &&
+	test_must_fail git branch -d to-delete 2>err &&
+	grep "not fully merged" err
+'
+
 test_expect_success 'git branch -v -d t should work' '
 	git branch t &&
 	git rev-parse --verify refs/heads/t &&
@@ -1383,7 +1463,7 @@ test_expect_success 'branch --delete --force removes dangling branch' '
 
 test_expect_success 'use --edit-description' '
 	EDITOR=: git branch --edit-description &&
-	test_must_fail git config branch.main.description &&
+	test_expect_code 1 git config branch.main.description &&
 
 	write_script editor <<-\EOF &&
 		echo "New contents" >"$1"