Subject: [PATCH v6 2/9] ref: check the full refname instead of basename

From: shejialuo <[email-masked]>
Date: Mon, 21 Oct 2024 21:34:22 +0800

In "files-backend.c::files_fsck_refs_name", we validate the refname
format by using "check_refname_format" to check the basename of the
iterator with "REFNAME_ALLOW_ONELEVEL" flag.

However, this is a bad implementation. Although we doesn't allow a
single "@" in ".git" directory, we do allow "refs/heads/@". So, we will
report an error wrongly when there is a "refs/heads/@" ref by using one
level refname "@".

Because we just check one level refname, we either cannot check the
other parts of the full refname. And we will ignore the following
errors:

  "refs/heads/ new-feature/test"
  "refs/heads/~new-feature/test"

In order to fix the above problem, enhance "files_fsck_refs_name" to use
the full name for "check_refname_format". Then, replace the tests which
are related to "@" and add tests to exercise the above situations.

Mentored-by: Patrick Steinhardt <[email-masked]>
Mentored-by: Karthik Nayak <[email-masked]>
Signed-off-by: shejialuo <[email-masked]>
---
 refs/files-backend.c     |  4 ++--
 t/t0602-reffiles-fsck.sh | 30 +++++++++++++++++++++++-------
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 03d2503276..f246c92684 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -3519,10 +3519,10 @@ static int files_fsck_refs_name(struct ref_store *ref_store UNUSED,
 	if (iter->basename[0] != '.' && ends_with(iter->basename, ".lock"))
 		goto cleanup;
 
-	if (check_refname_format(iter->basename, REFNAME_ALLOW_ONELEVEL)) {
+	strbuf_addf(&sb, "%s/%s", refs_check_dir, iter->relative_path);
+	if (check_refname_format(sb.buf, 0)) {
 		struct fsck_ref_report report = { 0 };
 
-		strbuf_addf(&sb, "%s/%s", refs_check_dir, iter->relative_path);
 		report.path = sb.buf;
 		ret = fsck_report_ref(o, &report,
 				      FSCK_MSG_BAD_REF_NAME,
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 71a4d1a5ae..0aee377439 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -25,6 +25,13 @@ test_expect_success 'ref name should be checked' '
 	git tag tag-2 &&
 	git tag multi_hierarchy/tag-2 &&
 
+	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/@ &&
+	git refs verify 2>err &&
+	cat >expect <<-EOF &&
+	EOF
+	test_must_be_empty err &&
+	rm $branch_dir_prefix/@ &&
+
 	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/.branch-1 &&
 	test_must_fail git refs verify 2>err &&
 	cat >expect <<-EOF &&
@@ -33,20 +40,20 @@ test_expect_success 'ref name should be checked' '
 	rm $branch_dir_prefix/.branch-1 &&
 	test_cmp expect err &&
 
-	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/@ &&
+	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/'\'' branch-1'\'' &&
 	test_must_fail git refs verify 2>err &&
 	cat >expect <<-EOF &&
-	error: refs/heads/@: badRefName: invalid refname format
+	error: refs/heads/ branch-1: badRefName: invalid refname format
 	EOF
-	rm $branch_dir_prefix/@ &&
+	rm $branch_dir_prefix/'\'' branch-1'\'' &&
 	test_cmp expect err &&
 
-	cp $tag_dir_prefix/multi_hierarchy/tag-2 $tag_dir_prefix/multi_hierarchy/@ &&
+	cp $tag_dir_prefix/multi_hierarchy/tag-2 $tag_dir_prefix/multi_hierarchy/'\''~tag-2'\'' &&
 	test_must_fail git refs verify 2>err &&
 	cat >expect <<-EOF &&
-	error: refs/tags/multi_hierarchy/@: badRefName: invalid refname format
+	error: refs/tags/multi_hierarchy/~tag-2: badRefName: invalid refname format
 	EOF
-	rm $tag_dir_prefix/multi_hierarchy/@ &&
+	rm $tag_dir_prefix/multi_hierarchy/'\''~tag-2'\'' &&
 	test_cmp expect err &&
 
 	cp $tag_dir_prefix/tag-1 $tag_dir_prefix/tag-1.lock &&
@@ -60,6 +67,15 @@ test_expect_success 'ref name should be checked' '
 	error: refs/tags/.lock: badRefName: invalid refname format
 	EOF
 	rm $tag_dir_prefix/.lock &&
+	test_cmp expect err &&
+
+	mkdir $tag_dir_prefix/'\''~new-feature'\'' &&
+	cp $tag_dir_prefix/tag-1 $tag_dir_prefix/'\''~new-feature'\''/tag-1 &&
+	test_must_fail git refs verify 2>err &&
+	cat >expect <<-EOF &&
+	error: refs/tags/~new-feature/tag-1: badRefName: invalid refname format
+	EOF
+	rm -rf $tag_dir_prefix/'\''~new-feature'\'' &&
 	test_cmp expect err
 '
 
@@ -84,7 +100,7 @@ test_expect_success 'ref name check should be adapted into fsck messages' '
 	rm $branch_dir_prefix/.branch-1 &&
 	test_cmp expect err &&
 
-	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/@ &&
+	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/'\''~branch-1'\'' &&
 	git -c fsck.badRefName=ignore refs verify 2>err &&
 	test_must_be_empty err
 '
-- 
2.47.0