builtin/fsck: move generic HEAD check into `refs_fsck()`

Move the check that detects "HEAD" refs that do not point at a branch
into `refs_fsck()`. This follows the same motivation as the preceding
commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

6 files changed, 21 insertions, 14 deletions

diff --git a/Documentation/fsck-msgids.adoc b/Documentation/fsck-msgids.adoc
index 76609321f6..6a4db3a991 100644
--- a/Documentation/fsck-msgids.adoc
+++ b/Documentation/fsck-msgids.adoc
@@ -13,6 +13,9 @@
 `badGpgsig`::
 	(ERROR) A tag contains a bad (truncated) signature (e.g., `gpgsig`) header.
 
+`badHeadTarget`::
+	(ERROR) The `HEAD` ref is a symref that does not refer to a branch.
+
 `badHeaderContinuation`::
 	(ERROR) A continuation header (such as for `gpgsig`) is unexpectedly truncated.
 
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 4dd4d74d1e..5dda441f45 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -728,13 +728,6 @@ static void fsck_head_link(const char *head_ref_name,
 		error(_("invalid %s"), head_ref_name);
 		return;
 	}
-	if (strcmp(*head_points_at, head_ref_name) &&
-	    !starts_with(*head_points_at, "refs/heads/")) {
-		errors_found |= ERROR_REFS;
-		error(_("%s points to something strange (%s)"),
-		      head_ref_name, *head_points_at);
-		return;
-	}
 
 	return;
 }
diff --git a/fsck.h b/fsck.h
index 1f472b7daa..65ecbb7fe1 100644
--- a/fsck.h
+++ b/fsck.h
@@ -30,6 +30,7 @@ enum fsck_msg_type {
 	FUNC(BAD_DATE_OVERFLOW, ERROR) \
 	FUNC(BAD_EMAIL, ERROR) \
 	FUNC(BAD_GPGSIG, ERROR) \
+	FUNC(BAD_HEAD_TARGET, ERROR) \
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
 	FUNC(BAD_PACKED_REF_ENTRY, ERROR) \
diff --git a/refs.c b/refs.c
index c3528862c6..a772d371cd 100644
--- a/refs.c
+++ b/refs.c
@@ -334,8 +334,18 @@ int refs_fsck_ref(struct ref_store *refs UNUSED, struct fsck_options *o,
 
 int refs_fsck_symref(struct ref_store *refs UNUSED, struct fsck_options *o,
 		     struct fsck_ref_report *report,
-		     const char *refname UNUSED, const char *target)
+		     const char *refname, const char *target)
 {
+	const char *stripped_refname;
+
+	parse_worktree_ref(refname, NULL, NULL, &stripped_refname);
+
+	if (!strcmp(stripped_refname, "HEAD") &&
+	    !starts_with(target, "refs/heads/") &&
+	    fsck_report_ref(o, report, FSCK_MSG_BAD_HEAD_TARGET,
+			    "HEAD points to non-branch '%s'", target))
+		return -1;
+
 	if (is_root_ref(target))
 		return 0;
 
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 479f3d528e..3c1f553b81 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -910,10 +910,10 @@ test_expect_success 'complains about broken root ref' '
 	git init repo &&
 	(
 		cd repo &&
-		echo "ref: refs/../HEAD" >.git/HEAD &&
+		echo "ref: refs/heads/../HEAD" >.git/HEAD &&
 		test_must_fail git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: HEAD: badReferentName: points to invalid refname ${SQ}refs/../HEAD${SQ}
+		error: HEAD: badReferentName: points to invalid refname ${SQ}refs/heads/../HEAD${SQ}
 		EOF
 		test_cmp expect err
 	)
@@ -926,10 +926,10 @@ test_expect_success 'complains about broken root ref in worktree' '
 		cd repo &&
 		test_commit initial &&
 		git worktree add ../worktree &&
-		echo "ref: refs/../HEAD" >.git/worktrees/worktree/HEAD &&
+		echo "ref: refs/heads/../HEAD" >.git/worktrees/worktree/HEAD &&
 		test_must_fail git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: worktrees/worktree/HEAD: badReferentName: points to invalid refname ${SQ}refs/../HEAD${SQ}
+		error: worktrees/worktree/HEAD: badReferentName: points to invalid refname ${SQ}refs/heads/../HEAD${SQ}
 		EOF
 		test_cmp expect err
 	)
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 900c1b2eb2..3fae05f9d9 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -113,7 +113,7 @@ test_expect_success 'HEAD link pointing at a funny place' '
 	test-tool ref-store main create-symref HEAD refs/funny/place &&
 	# avoid corrupt/broken HEAD from interfering with repo discovery
 	test_must_fail env GIT_DIR=.git git fsck 2>out &&
-	test_grep "HEAD points to something strange" out
+	test_grep "HEAD: badHeadTarget: HEAD points to non-branch ${SQ}refs/funny/place${SQ}" out
 '
 
 test_expect_success REFFILES 'HEAD link pointing at a funny object (from different wt)' '
@@ -148,7 +148,7 @@ test_expect_success 'other worktree HEAD link pointing at a funny place' '
 	git worktree add other &&
 	git -C other symbolic-ref HEAD refs/funny/place &&
 	test_must_fail git fsck 2>out &&
-	test_grep "worktrees/other/HEAD points to something strange" out
+	test_grep "worktrees/other/HEAD: badHeadTarget: HEAD points to non-branch ${SQ}refs/funny/place${SQ}" out
 '
 
 test_expect_success 'commit with multiple signatures is okay' '