Merge branch 'nd/per-worktree-ref-iteration'

The code to traverse objects for reachability, used to decide what
objects are unreferenced and expendable, have been taught to also
consider per-worktree refs of other worktrees as starting points to
prevent data loss.

* nd/per-worktree-ref-iteration:
  git-worktree.txt: correct linkgit command name
  reflog expire: cover reflog from all worktrees
  fsck: check HEAD and reflog from other worktrees
  fsck: move fsck_head_link() to get_default_heads() to avoid some globals
  revision.c: better error reporting on ref from different worktrees
  revision.c: correct a parameter name
  refs: new ref types to make per-worktree refs visible to all worktrees
  Add a place for (not) sharing stuff between worktrees
  refs.c: indent with tabs, not spaces

1 files changed, 35 insertions, 0 deletions

diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index b5677d26a4..e20e8fa830 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -101,6 +101,41 @@ test_expect_success 'HEAD link pointing at a funny place' '
 	grep "HEAD points to something strange" out
 '
 
+test_expect_success 'HEAD link pointing at a funny object (from different wt)' '
+	test_when_finished "mv .git/SAVED_HEAD .git/HEAD" &&
+	test_when_finished "rm -rf .git/worktrees wt" &&
+	git worktree add wt &&
+	mv .git/HEAD .git/SAVED_HEAD &&
+	echo $ZERO_OID >.git/HEAD &&
+	# avoid corrupt/broken HEAD from interfering with repo discovery
+	test_must_fail git -C wt fsck 2>out &&
+	grep "main-worktree/HEAD: detached HEAD points" out
+'
+
+test_expect_success 'other worktree HEAD link pointing at a funny object' '
+	test_when_finished "rm -rf .git/worktrees other" &&
+	git worktree add other &&
+	echo $ZERO_OID >.git/worktrees/other/HEAD &&
+	test_must_fail git fsck 2>out &&
+	grep "worktrees/other/HEAD: detached HEAD points" out
+'
+
+test_expect_success 'other worktree HEAD link pointing at missing object' '
+	test_when_finished "rm -rf .git/worktrees other" &&
+	git worktree add other &&
+	echo "Contents missing from repo" | git hash-object --stdin >.git/worktrees/other/HEAD &&
+	test_must_fail git fsck 2>out &&
+	grep "worktrees/other/HEAD: invalid sha1 pointer" out
+'
+
+test_expect_success 'other worktree HEAD link pointing at a funny place' '
+	test_when_finished "rm -rf .git/worktrees other" &&
+	git worktree add other &&
+	echo "ref: refs/funny/place" >.git/worktrees/other/HEAD &&
+	test_must_fail git fsck 2>out &&
+	grep "worktrees/other/HEAD points to something strange" out
+'
+
 test_expect_success 'email without @ is okay' '
 	git cat-file commit HEAD >basis &&
 	sed "s/@/AT/" basis >okay &&