patch, 10 partsadd more ref consistency checks

refs/files-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 64f51f0da9..0a4912c009 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -20,6 +20,7 @@
 #include "../lockfile.h"
 #include "../object.h"
 #include "../object-file.h"
+#include "../packfile.h"
 #include "../path.h"
 #include "../dir.h"
 #include "../chdir-notify.h"
@@ -3589,6 +3590,34 @@ static int files_fsck_symref_target(struct fsck_options *o,
 	return ret;
 }
 
+static int files_fsck_refs_oid(struct fsck_options *o,
+			       struct ref_store *ref_store,
+			       struct fsck_ref_report report,
+			       const char *target_name,
+			       struct object_id *oid)
+{
+	struct object *obj;
+	int ret = 0;
+
+	if (is_promisor_object(ref_store->repo, oid))
+		return 0;
+
+	obj = parse_object(ref_store->repo, oid);
+	if (!obj) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_REF_CONTENT,
+				       "points to non-existing object %s",
+				       oid_to_hex(oid));
+	} else if (obj->type != OBJ_COMMIT && is_branch(target_name)) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_REF_CONTENT,
+				       "points to non-commit object %s",
+				       oid_to_hex(oid));
+	}
+
+	return ret;
+}
+
 static int files_fsck_refs_content(struct ref_store *ref_store,
 				   struct fsck_options *o,
 				   const char *target_name,
@@ -3654,18 +3683,19 @@ static int files_fsck_refs_content(struct ref_store *ref_store,
 	}
 
 	if (!(type & REF_ISSYMREF)) {
+		ret |= files_fsck_refs_oid(o, ref_store, report, target_name, &oid);
+
 		if (!*trailing) {
-			ret = fsck_report_ref(o, &report,
-					      FSCK_MSG_REF_MISSING_NEWLINE,
-					      "misses LF at the end");
-			goto cleanup;
-		}
-		if (*trailing != '\n' || *(trailing + 1)) {
-			ret = fsck_report_ref(o, &report,
-					      FSCK_MSG_TRAILING_REF_CONTENT,
-					      "has trailing garbage: '%s'", trailing);
-			goto cleanup;
+			ret |= fsck_report_ref(o, &report,
+					       FSCK_MSG_REF_MISSING_NEWLINE,
+					       "misses LF at the end");
+		} else if (*trailing != '\n' || *(trailing + 1)) {
+			ret |= fsck_report_ref(o, &report,
+					       FSCK_MSG_TRAILING_REF_CONTENT,
+					       "has trailing garbage: '%s'", trailing);
 		}
+
+		goto cleanup;
 	} else {
 		ret = files_fsck_symref_target(o, &report, &referent, 0);
 		goto cleanup;
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index d4a08b823b..75f234a94a 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -161,8 +161,10 @@ test_expect_success 'regular ref content should be checked (individual)' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
+	tag_dir_prefix=.git/refs/tags &&
 	cd repo &&
 	test_commit default &&
+	git branch branch-1 &&
 	mkdir -p "$branch_dir_prefix/a/b" &&
 
 	git refs verify 2>err &&
@@ -198,6 +200,28 @@ test_expect_success 'regular ref content should be checked (individual)' '
 	rm $branch_dir_prefix/branch-no-newline &&
 	test_cmp expect err &&
 
+	for non_existing_oid in "$(test_oid 001)" "$(test_oid 002)"
+	do
+		printf "%s\n" $non_existing_oid >$branch_dir_prefix/invalid-commit &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: refs/heads/invalid-commit: badRefContent: points to non-existing object $non_existing_oid
+		EOF
+		rm $branch_dir_prefix/invalid-commit &&
+		test_cmp expect err || return 1
+	done &&
+
+	for tree_oid in "$(git rev-parse main^{tree})" "$(git rev-parse branch-1^{tree})"
+	do
+		printf "%s\n" $tree_oid >$branch_dir_prefix/branch-tree &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: refs/heads/branch-tree: badRefContent: points to non-commit object $tree_oid
+		EOF
+		rm $branch_dir_prefix/branch-tree &&
+		test_cmp expect err || return 1
+	done &&
+
 	for trailing_content in " garbage" "    more garbage"
 	do
 		printf "%s" "$(git rev-parse main)$trailing_content" >$branch_dir_prefix/branch-garbage &&
@@ -244,15 +268,21 @@ test_expect_success 'regular ref content should be checked (aggregate)' '
 	bad_content_1=$(git rev-parse main)x &&
 	bad_content_2=xfsazqfxcadas &&
 	bad_content_3=Xfsazqfxcadas &&
+	non_existing_oid=$(test_oid 001) &&
+	tree_oid=$(git rev-parse main^{tree}) &&
 	printf "%s" $bad_content_1 >$tag_dir_prefix/tag-bad-1 &&
 	printf "%s" $bad_content_2 >$tag_dir_prefix/tag-bad-2 &&
 	printf "%s" $bad_content_3 >$branch_dir_prefix/a/b/branch-bad &&
 	printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
 	printf "%s garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage &&
+	printf "%s\n" $non_existing_oid >$branch_dir_prefix/branch-non-existing-oid &&
+	printf "%s\n" $tree_oid >$branch_dir_prefix/branch-tree &&
 
 	test_must_fail git refs verify 2>err &&
 	cat >expect <<-EOF &&
 	error: refs/heads/a/b/branch-bad: badRefContent: $bad_content_3
+	error: refs/heads/branch-non-existing-oid: badRefContent: points to non-existing object $non_existing_oid
+	error: refs/heads/branch-tree: badRefContent: points to non-commit object $tree_oid
 	error: refs/tags/tag-bad-1: badRefContent: $bad_content_1
 	error: refs/tags/tag-bad-2: badRefContent: $bad_content_2
 	warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''

builtin/refs.c, worktree.c, worktree.h

diff --git a/builtin/refs.c b/builtin/refs.c
index a29f195834..55ff5dae11 100644
--- a/builtin/refs.c
+++ b/builtin/refs.c
@@ -88,7 +88,7 @@ static int cmd_refs_verify(int argc, const char **argv, const char *prefix,
 	git_config(git_fsck_config, &fsck_refs_options);
 	prepare_repo_settings(the_repository);
 
-	worktrees = get_worktrees();
+	worktrees = get_worktrees_without_reading_head();
 	for (size_t i = 0; worktrees[i]; i++)
 		ret |= refs_fsck(get_worktree_ref_store(worktrees[i]),
 				 &fsck_refs_options, worktrees[i]);
diff --git a/worktree.c b/worktree.c
index af68b24f9d..74cb463e51 100644
--- a/worktree.c
+++ b/worktree.c
@@ -174,6 +174,11 @@ struct worktree **get_worktrees(void)
 	return get_worktrees_internal(0);
 }
 
+struct worktree **get_worktrees_without_reading_head(void)
+{
+	return get_worktrees_internal(1);
+}
+
 const char *get_worktree_git_dir(const struct worktree *wt)
 {
 	if (!wt)
diff --git a/worktree.h b/worktree.h
index 38145df80f..1ba4a161a0 100644
--- a/worktree.h
+++ b/worktree.h
@@ -30,6 +30,12 @@ struct worktree {
  */
 struct worktree **get_worktrees(void);
 
+/*
+ * Like `get_worktrees`, but does not read HEAD. This is useful when checking
+ * the consistency, as reading HEAD may not be necessary.
+ */
+struct worktree **get_worktrees_without_reading_head(void);
+
 /*
  * Returns 1 if linked worktrees exist, 0 otherwise.
  */

refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 3406f1e71d..d9eb2f8b71 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -4,6 +4,7 @@
 #include "../config.h"
 #include "../dir.h"
 #include "../gettext.h"
+#include "../fsck.h"
 #include "../hash.h"
 #include "../hex.h"
 #include "../refs.h"
@@ -1747,15 +1748,39 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
-static int packed_fsck(struct ref_store *ref_store UNUSED,
-		       struct fsck_options *o UNUSED,
+static int packed_fsck(struct ref_store *ref_store,
+		       struct fsck_options *o,
 		       struct worktree *wt)
 {
+	struct packed_ref_store *refs = packed_downcast(ref_store,
+							REF_STORE_READ, "fsck");
+	struct stat st;
+	int ret = 0;
 
 	if (!is_main_worktree(wt))
-		return 0;
+		goto cleanup;
 
-	return 0;
+	/*
+	 * If the packed-refs file doesn't exist, there's nothing to
+	 * check.
+	 */
+	if (lstat(refs->path, &st) < 0)
+		goto cleanup;
+
+	if (o->verbose)
+		fprintf_ln(stderr, "Checking packed-refs file %s", refs->path);
+
+	if (!S_ISREG(st.st_mode)) {
+		struct fsck_ref_report report = { 0 };
+		report.path = "packed-refs";
+
+		ret = fsck_report_ref(o, &report, FSCK_MSG_BAD_REF_FILETYPE,
+				      "not a regular file");
+		goto cleanup;
+	}
+
+cleanup:
+	return ret;
 }
 
 struct ref_storage_be refs_be_packed = {
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 75f234a94a..307f94a3ca 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -626,4 +626,24 @@ test_expect_success 'ref content checks should work with worktrees' '
 	test_cmp expect err
 '
 
+test_expect_success SYMLINKS 'the filetype of packed-refs should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	cd repo &&
+	test_commit default &&
+	git branch branch-1 &&
+	git branch branch-2 &&
+	git branch branch-3 &&
+	git pack-refs --all &&
+
+	mv .git/packed-refs .git/packed-refs-back &&
+	ln -sf packed-refs-bak .git/packed-refs &&
+	test_must_fail git refs verify 2>err &&
+	cat >expect <<-EOF &&
+	error: packed-refs: badRefFiletype: not a regular file
+	EOF
+	rm .git/packed-refs &&
+	test_cmp expect err
+'
+
 test_done

Documentation/fsck-msgids.txt, fsck.h, refs/files-backend.c, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index b14bc44ca4..34375a3143 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -16,6 +16,10 @@
 `badObjectSha1`::
 	(ERROR) An object has a bad sha1.
 
+`badPackedRefHeader`::
+	(ERROR) The "packed-refs" file contains an invalid
+	header.
+
 `badParentSha1`::
 	(ERROR) A commit object has a bad parent sha1.
 
@@ -176,6 +180,13 @@
 `nullSha1`::
 	(WARN) Tree contains entries pointing to a null sha1.
 
+`packedRefEntryNotTerminated`::
+	(ERROR) The "packed-refs" file contains an entry that is
+	not terminated by a newline.
+
+`packedRefMissingHeader`::
+	(INFO) The "packed-refs" file does not contain the header.
+
 `refMissingNewline`::
 	(INFO) A loose ref that does not end with newline(LF). As
 	valid implementations of Git never created such a loose ref
@@ -208,6 +219,11 @@
 `treeNotSorted`::
 	(ERROR) A tree is not properly sorted.
 
+`unknownPackedRefHeader`::
+	(INFO) The "packed-refs" header starts with "# pack-refs with:"
+	but the remaining content is not the same as what `git pack-refs`
+	would write.
+
 `unknownType`::
 	(ERROR) Found an unknown object type.
 
diff --git a/fsck.h b/fsck.h
index a44c231a5f..026ad1d537 100644
--- a/fsck.h
+++ b/fsck.h
@@ -30,6 +30,7 @@ enum fsck_msg_type {
 	FUNC(BAD_EMAIL, ERROR) \
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
+	FUNC(BAD_PACKED_REF_HEADER, ERROR) \
 	FUNC(BAD_PARENT_SHA1, ERROR) \
 	FUNC(BAD_REF_CONTENT, ERROR) \
 	FUNC(BAD_REF_FILETYPE, ERROR) \
@@ -53,6 +54,7 @@ enum fsck_msg_type {
 	FUNC(MISSING_TYPE, ERROR) \
 	FUNC(MISSING_TYPE_ENTRY, ERROR) \
 	FUNC(MULTIPLE_AUTHORS, ERROR) \
+	FUNC(PACKED_REF_ENTRY_NOT_TERMINATED, ERROR) \
 	FUNC(TREE_NOT_SORTED, ERROR) \
 	FUNC(UNKNOWN_TYPE, ERROR) \
 	FUNC(ZERO_PADDED_DATE, ERROR) \
@@ -90,6 +92,8 @@ enum fsck_msg_type {
 	FUNC(REF_MISSING_NEWLINE, INFO) \
 	FUNC(SYMREF_TARGET_IS_NOT_A_REF, INFO) \
 	FUNC(TRAILING_REF_CONTENT, INFO) \
+	FUNC(UNKNOWN_PACKED_REF_HEADER, INFO) \
+	FUNC(PACKED_REF_MISSING_HEADER, INFO) \
 	/* ignored (elevated when requested) */ \
 	FUNC(EXTRA_HEADER_ENTRY, IGNORE)
 
@@ -163,6 +167,7 @@ struct fsck_options {
 	fsck_error error_func;
 	unsigned strict;
 	unsigned verbose;
+	int safe_object_check;
 	enum fsck_msg_type *msg_type;
 	struct oidset skip_oids;
 	struct oidset gitmodules_found;
@@ -198,6 +203,7 @@ struct fsck_options {
 }
 #define FSCK_REFS_OPTIONS_DEFAULT { \
 	.error_func = fsck_refs_error_function, \
+	.safe_object_check = 1, \
 }
 
 /* descend in all linked child objects
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 0a4912c009..66eae36184 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -3599,7 +3599,7 @@ static int files_fsck_refs_oid(struct fsck_options *o,
 	struct object *obj;
 	int ret = 0;
 
-	if (is_promisor_object(ref_store->repo, oid))
+	if (!o->safe_object_check || is_promisor_object(ref_store->repo, oid))
 		return 0;
 
 	obj = parse_object(ref_store->repo, oid);
@@ -3819,8 +3819,8 @@ static int files_fsck(struct ref_store *ref_store,
 	struct files_ref_store *refs =
 		files_downcast(ref_store, REF_STORE_READ, "fsck");
 
-	return files_fsck_refs(ref_store, o, wt) |
-	       refs->packed_ref_store->be->fsck(refs->packed_ref_store, o, wt);
+	return refs->packed_ref_store->be->fsck(refs->packed_ref_store, o, wt) |
+	       files_fsck_refs(ref_store, o, wt);
 }
 
 struct ref_storage_be refs_be_files = {
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index d9eb2f8b71..3b11abe5f8 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1748,12 +1748,100 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
+static int packed_fsck_ref_next_line(struct fsck_options *o,
+				     int line_number, const char *start,
+				     const char *eof, const char **eol)
+{
+	int ret = 0;
+
+	*eol = memchr(start, '\n', eof - start);
+	if (!*eol) {
+		struct strbuf packed_entry = STRBUF_INIT;
+		struct fsck_ref_report report = { 0 };
+
+		strbuf_addf(&packed_entry, "packed-refs line %d", line_number);
+		report.path = packed_entry.buf;
+		ret = fsck_report_ref(o, &report,
+				      FSCK_MSG_PACKED_REF_ENTRY_NOT_TERMINATED,
+				      "'%.*s' is not terminated with a newline",
+				      (int)(eof - start), start);
+
+		/*
+		 * There is no newline but we still want to parse it to the end of
+		 * the buffer.
+		 */
+		*eol = eof;
+		strbuf_release(&packed_entry);
+	}
+
+	return ret;
+}
+
+static int packed_fsck_ref_header(struct fsck_options *o, const char *start, const char *eol)
+{
+	const char *err_fmt = NULL;
+	int fsck_msg_id = -1;
+
+	if (!starts_with(start, "# pack-refs with:")) {
+		err_fmt = "'%.*s' does not start with '# pack-refs with:'";
+		fsck_msg_id = FSCK_MSG_BAD_PACKED_REF_HEADER;
+	} else if (strncmp(start, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER))) {
+		err_fmt = "'%.*s' is not the official packed-refs header";
+		fsck_msg_id = FSCK_MSG_UNKNOWN_PACKED_REF_HEADER;
+	}
+
+	if (err_fmt && fsck_msg_id >= 0) {
+		struct fsck_ref_report report = { 0 };
+		report.path = "packed-refs.header";
+
+		return fsck_report_ref(o, &report, fsck_msg_id, err_fmt,
+				       (int)(eol - start), start);
+
+	}
+
+	return 0;
+}
+
+static int packed_fsck_ref_content(struct fsck_options *o,
+				   const char *start, const char *eof)
+{
+	int line_number = 1;
+	const char *eol;
+	int ret = 0;
+
+	ret |= packed_fsck_ref_next_line(o, line_number, start, eof, &eol);
+	if (*start == '#') {
+		ret |= packed_fsck_ref_header(o, start, eol);
+
+		start = eol + 1;
+		line_number++;
+	} else {
+		struct fsck_ref_report report = { 0 };
+		report.path = "packed-refs";
+
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_PACKED_REF_MISSING_HEADER,
+				       "missing header line");
+	}
+
+	/*
+	 * If there is anything wrong during the parsing of the "packed-refs"
+	 * file, we should not check the object of the refs.
+	 */
+	if (ret)
+		o->safe_object_check = 0;
+
+
+	return ret;
+}
+
 static int packed_fsck(struct ref_store *ref_store,
 		       struct fsck_options *o,
 		       struct worktree *wt)
 {
 	struct packed_ref_store *refs = packed_downcast(ref_store,
 							REF_STORE_READ, "fsck");
+	struct strbuf packed_ref_content = STRBUF_INIT;
 	struct stat st;
 	int ret = 0;
 
@@ -1779,7 +1867,24 @@ static int packed_fsck(struct ref_store *ref_store,
 		goto cleanup;
 	}
 
+	if (strbuf_read_file(&packed_ref_content, refs->path, 0) < 0) {
+		/*
+		 * Although we have checked that the file exists, there is a possibility
+		 * that it has been removed between the lstat() and the read attempt by
+		 * another process. In that case, we should not report an error.
+		 */
+		if (errno == ENOENT)
+			goto cleanup;
+
+		ret = error_errno("could not read %s", refs->path);
+		goto cleanup;
+	}
+
+	ret = packed_fsck_ref_content(o, packed_ref_content.buf,
+				      packed_ref_content.buf + packed_ref_content.len);
+
 cleanup:
+	strbuf_release(&packed_ref_content);
 	return ret;
 }
 
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 307f94a3ca..6c729e749a 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -646,4 +646,48 @@ test_expect_success SYMLINKS 'the filetype of packed-refs should be checked' '
 	test_cmp expect err
 '
 
+test_expect_success 'packed-refs header should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	cd repo &&
+	test_commit default &&
+
+	git refs verify 2>err &&
+	test_must_be_empty err &&
+
+	printf "$(git rev-parse main) refs/heads/main\n" >.git/packed-refs &&
+	git refs verify 2>err &&
+	cat >expect <<-EOF &&
+	warning: packed-refs: packedRefMissingHeader: missing header line
+	EOF
+	rm .git/packed-refs &&
+	test_cmp expect err &&
+
+	for bad_header in "# pack-refs wit: peeled fully-peeled sorted " \
+			  "# pack-refs with traits: peeled fully-peeled sorted " \
+			  "# pack-refs with a: peeled fully-peeled"
+	do
+		printf "%s\n" "$bad_header" >.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs.header: badPackedRefHeader: '\''$bad_header'\'' does not start with '\''# pack-refs with:'\''
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err || return 1
+	done &&
+
+	for unknown_header in "# pack-refs with: peeled fully-peeled sorted garbage" \
+			      "# pack-refs with: peeled" \
+			      "# pack-refs with: peeled peeled-fully sort"
+	do
+		printf "%s\n" "$unknown_header" >.git/packed-refs &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: packed-refs.header: unknownPackedRefHeader: '\''$unknown_header'\'' is not the official packed-refs header
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err || return 1
+	done
+'
+
 test_done

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 3b11abe5f8..f6142a4402 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -493,6 +493,23 @@ static void verify_buffer_safe(struct snapshot *snapshot)
 				 last_line, eof - last_line);
 }
 
+/*
+ * When parsing the "packed-refs" file, we will parse it line by line.
+ * Because we know the start pointer of the refname and the next
+ * newline pointer, we could calculate the length of the refname by
+ * subtracting the two pointers. However, there is a corner case where
+ * the refname contains corrupted embedded NULL binaries. And
+ * `check_refname_format()` will not catch this when the truncated
+ * refname is still a valid refname. To prevent this, we need to check
+ * whether the refname contains the NULL binaries.
+ */
+static int refname_contains_null(struct strbuf refname)
+{
+	if (refname.len != strlen(refname.buf))
+		return 1;
+	return 0;
+}
+
 #define SMALL_FILE_SIZE (32*1024)
 
 /*
@@ -894,6 +911,9 @@ static int next_record(struct packed_ref_iterator *iter)
 	strbuf_add(&iter->refname_buf, p, eol - p);
 	iter->base.refname = iter->refname_buf.buf;
 
+	if (refname_contains_null(iter->refname_buf))
+		die("packed refname contains embedded NULL: %s", iter->base.refname);
+
 	if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) {
 		if (!refname_is_safe(iter->base.refname))
 			die("packed refname is dangerous: %s",

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index 34375a3143..2a7ec7592e 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -16,6 +16,9 @@
 `badObjectSha1`::
 	(ERROR) An object has a bad sha1.
 
+`badPackedRefEntry`::
+	(ERROR) The "packed-refs" file contains an invalid entry.
+
 `badPackedRefHeader`::
 	(ERROR) The "packed-refs" file contains an invalid
 	header.
diff --git a/fsck.h b/fsck.h
index 026ad1d537..4fca304b72 100644
--- a/fsck.h
+++ b/fsck.h
@@ -30,6 +30,7 @@ enum fsck_msg_type {
 	FUNC(BAD_EMAIL, ERROR) \
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
+	FUNC(BAD_PACKED_REF_ENTRY, ERROR) \
 	FUNC(BAD_PACKED_REF_HEADER, ERROR) \
 	FUNC(BAD_PARENT_SHA1, ERROR) \
 	FUNC(BAD_REF_CONTENT, ERROR) \
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index f6142a4402..6e521a9f87 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1822,7 +1822,96 @@ static int packed_fsck_ref_header(struct fsck_options *o, const char *start, con
 	return 0;
 }
 
+static int packed_fsck_ref_peeled_line(struct fsck_options *o,
+				       struct ref_store *ref_store, int line_number,
+				       const char *start, const char *eol)
+{
+	struct strbuf peeled_entry = STRBUF_INIT;
+	struct fsck_ref_report report = { 0 };
+	struct object_id peeled;
+	const char *p;
+	int ret = 0;
+
+	strbuf_addf(&peeled_entry, "packed-refs line %d", line_number);
+	report.path = peeled_entry.buf;
+
+	start++;
+	if (parse_oid_hex_algop(start, &peeled, &p, ref_store->repo->hash_algo)) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "'%.*s' has invalid peeled oid",
+				       (int)(eol - start), start);
+		goto cleanup;
+	}
+
+	if (p != eol) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "has trailing garbage after peeled oid '%.*s'",
+				       (int)(eol - p), p);
+		goto cleanup;
+	}
+
+cleanup:
+	strbuf_release(&peeled_entry);
+	return ret;
+}
+
+static int packed_fsck_ref_main_line(struct fsck_options *o,
+				     struct ref_store *ref_store, int line_number,
+				     const char *start, const char *eol)
+{
+	struct strbuf packed_entry = STRBUF_INIT;
+	struct fsck_ref_report report = { 0 };
+	struct strbuf refname = STRBUF_INIT;
+	struct object_id oid;
+	const char *p;
+	int ret = 0;
+
+	strbuf_addf(&packed_entry, "packed-refs line %d", line_number);
+	report.path = packed_entry.buf;
+
+	if (parse_oid_hex_algop(start, &oid, &p, ref_store->repo->hash_algo)) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "'%.*s' has invalid oid",
+				       (int)(eol - start), start);
+		goto cleanup;
+	}
+
+	if (p == eol || !isspace(*p)) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "has no space after oid '%s' but with '%.*s'",
+				       oid_to_hex(&oid), (int)(eol - p), p);
+		goto cleanup;
+	}
+
+	p++;
+	strbuf_add(&refname, p, eol - p);
+	if (refname_contains_null(refname)) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "refname '%s' contains NULL binaries",
+				       refname.buf);
+		goto cleanup;
+	}
+
+	if (check_refname_format(refname.buf, 0)) {
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_REF_NAME,
+				       "has bad refname '%s'", refname.buf);
+		goto cleanup;
+	}
+
+cleanup:
+	strbuf_release(&packed_entry);
+	strbuf_release(&refname);
+	return ret;
+}
+
 static int packed_fsck_ref_content(struct fsck_options *o,
+				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
 {
 	int line_number = 1;
@@ -1844,6 +1933,20 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 				       "missing header line");
 	}
 
+	while (start < eof) {
+		ret |= packed_fsck_ref_next_line(o, line_number, start, eof, &eol);
+		ret |= packed_fsck_ref_main_line(o, ref_store, line_number, start, eol);
+		start = eol + 1;
+		line_number++;
+		if (start < eof && *start == '^') {
+			ret |= packed_fsck_ref_next_line(o, line_number, start, eof, &eol);
+			ret |= packed_fsck_ref_peeled_line(o, ref_store, line_number,
+							   start, eol);
+			start = eol + 1;
+			line_number++;
+		}
+	}
+
 	/*
 	 * If there is anything wrong during the parsing of the "packed-refs"
 	 * file, we should not check the object of the refs.
@@ -1900,7 +2003,7 @@ static int packed_fsck(struct ref_store *ref_store,
 		goto cleanup;
 	}
 
-	ret = packed_fsck_ref_content(o, packed_ref_content.buf,
+	ret = packed_fsck_ref_content(o, ref_store, packed_ref_content.buf,
 				      packed_ref_content.buf + packed_ref_content.len);
 
 cleanup:
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 6c729e749a..7e8b329425 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -690,4 +690,44 @@ test_expect_success 'packed-refs header should be checked' '
 	done
 '
 
+test_expect_success 'packed-refs content should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	cd repo &&
+	test_commit default &&
+	git branch branch-1 &&
+	git branch branch-2 &&
+	git tag -a annotated-tag-1 -m tag-1 &&
+	git tag -a annotated-tag-2 -m tag-2 &&
+
+	branch_1_oid=$(git rev-parse branch-1) &&
+	branch_2_oid=$(git rev-parse branch-2) &&
+	tag_1_oid=$(git rev-parse annotated-tag-1) &&
+	tag_2_oid=$(git rev-parse annotated-tag-2) &&
+	tag_1_peeled_oid=$(git rev-parse annotated-tag-1^{}) &&
+	tag_2_peeled_oid=$(git rev-parse annotated-tag-2^{}) &&
+	short_oid=$(printf "%s" $tag_1_peeled_oid | cut -c 1-4) &&
+
+	printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+	printf "%s\n" "$short_oid refs/heads/branch-1" >>.git/packed-refs &&
+	printf "%sx\n" "$branch_1_oid" >>.git/packed-refs &&
+	printf "%s   refs/heads/bad-branch\n" "$branch_2_oid" >>.git/packed-refs &&
+	printf "%s refs/heads/branch.\n" "$branch_2_oid" >>.git/packed-refs &&
+	printf "%s refs/tags/annotated-tag-3\n" "$tag_1_oid" >>.git/packed-refs &&
+	printf "^%s\n" "$short_oid" >>.git/packed-refs &&
+	printf "%s refs/tags/annotated-tag-4.\n" "$tag_2_oid" >>.git/packed-refs &&
+	printf "^%s garbage\n" "$tag_2_peeled_oid" >>.git/packed-refs &&
+	test_must_fail git refs verify 2>err &&
+	cat >expect <<-EOF &&
+	error: packed-refs line 2: badPackedRefEntry: '\''$short_oid refs/heads/branch-1'\'' has invalid oid
+	error: packed-refs line 3: badPackedRefEntry: has no space after oid '\''$branch_1_oid'\'' but with '\''x'\''
+	error: packed-refs line 4: badRefName: has bad refname '\''  refs/heads/bad-branch'\''
+	error: packed-refs line 5: badRefName: has bad refname '\''refs/heads/branch.'\''
+	error: packed-refs line 7: badPackedRefEntry: '\''$short_oid'\'' has invalid peeled oid
+	error: packed-refs line 8: badRefName: has bad refname '\''refs/tags/annotated-tag-4.'\''
+	error: packed-refs line 9: badPackedRefEntry: has trailing garbage after peeled oid '\'' garbage'\''
+	EOF
+	test_cmp expect err
+'
+
 test_done

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 6e521a9f87..7386e6bfce 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1768,6 +1768,29 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
+struct fsck_packed_ref_entry {
+	int line_number;
+
+	int has_peeled;
+	struct object_id oid;
+	struct object_id peeled;
+};
+
+static struct fsck_packed_ref_entry *create_fsck_packed_ref_entry(int line_number)
+{
+	struct fsck_packed_ref_entry *entry = xcalloc(1, sizeof(*entry));
+	entry->line_number = line_number;
+	entry->has_peeled = 0;
+	return entry;
+}
+
+static void free_fsck_packed_ref_entries(struct fsck_packed_ref_entry **entries, int nr)
+{
+	for (int i = 0; i < nr; i++)
+		free(entries[i]);
+	free(entries);
+}
+
 static int packed_fsck_ref_next_line(struct fsck_options *o,
 				     int line_number, const char *start,
 				     const char *eof, const char **eol)
@@ -1823,20 +1846,20 @@ static int packed_fsck_ref_header(struct fsck_options *o, const char *start, con
 }
 
 static int packed_fsck_ref_peeled_line(struct fsck_options *o,
-				       struct ref_store *ref_store, int line_number,
+				       struct ref_store *ref_store,
+				       struct fsck_packed_ref_entry *entry,
 				       const char *start, const char *eol)
 {
 	struct strbuf peeled_entry = STRBUF_INIT;
 	struct fsck_ref_report report = { 0 };
-	struct object_id peeled;
 	const char *p;
 	int ret = 0;
 
-	strbuf_addf(&peeled_entry, "packed-refs line %d", line_number);
+	strbuf_addf(&peeled_entry, "packed-refs line %d", entry->line_number + 1);
 	report.path = peeled_entry.buf;
 
 	start++;
-	if (parse_oid_hex_algop(start, &peeled, &p, ref_store->repo->hash_algo)) {
+	if (parse_oid_hex_algop(start, &entry->peeled, &p, ref_store->repo->hash_algo)) {
 		ret |= fsck_report_ref(o, &report,
 				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
 				       "'%.*s' has invalid peeled oid",
@@ -1858,20 +1881,20 @@ static int packed_fsck_ref_peeled_line(struct fsck_options *o,
 }
 
 static int packed_fsck_ref_main_line(struct fsck_options *o,
-				     struct ref_store *ref_store, int line_number,
+				     struct ref_store *ref_store,
+				     struct fsck_packed_ref_entry *entry,
 				     const char *start, const char *eol)
 {
 	struct strbuf packed_entry = STRBUF_INIT;
 	struct fsck_ref_report report = { 0 };
 	struct strbuf refname = STRBUF_INIT;
-	struct object_id oid;
 	const char *p;
 	int ret = 0;
 
-	strbuf_addf(&packed_entry, "packed-refs line %d", line_number);
+	strbuf_addf(&packed_entry, "packed-refs line %d", entry->line_number);
 	report.path = packed_entry.buf;
 
-	if (parse_oid_hex_algop(start, &oid, &p, ref_store->repo->hash_algo)) {
+	if (parse_oid_hex_algop(start, &entry->oid, &p, ref_store->repo->hash_algo)) {
 		ret |= fsck_report_ref(o, &report,
 				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
 				       "'%.*s' has invalid oid",
@@ -1883,7 +1906,7 @@ static int packed_fsck_ref_main_line(struct fsck_options *o,
 		ret |= fsck_report_ref(o, &report,
 				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
 				       "has no space after oid '%s' but with '%.*s'",
-				       oid_to_hex(&oid), (int)(eol - p), p);
+				       oid_to_hex(&entry->oid), (int)(eol - p), p);
 		goto cleanup;
 	}
 
@@ -1914,7 +1937,10 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
 {
+	struct fsck_packed_ref_entry **entries;
+	int entry_alloc = 20;
 	int line_number = 1;
+	int entry_nr = 0;
 	const char *eol;
 	int ret = 0;
 
@@ -1933,14 +1959,21 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 				       "missing header line");
 	}
 
+	ALLOC_ARRAY(entries, entry_alloc);
 	while (start < eof) {
+		struct fsck_packed_ref_entry *entry
+			= create_fsck_packed_ref_entry(line_number);
+		ALLOC_GROW(entries, entry_nr + 1, entry_alloc);
+		entries[entry_nr++] = entry;
+
 		ret |= packed_fsck_ref_next_line(o, line_number, start, eof, &eol);
-		ret |= packed_fsck_ref_main_line(o, ref_store, line_number, start, eol);
+		ret |= packed_fsck_ref_main_line(o, ref_store, entry, start, eol);
 		start = eol + 1;
 		line_number++;
 		if (start < eof && *start == '^') {
+			entry->has_peeled = 1;
 			ret |= packed_fsck_ref_next_line(o, line_number, start, eof, &eol);
-			ret |= packed_fsck_ref_peeled_line(o, ref_store, line_number,
+			ret |= packed_fsck_ref_peeled_line(o, ref_store, entry,
 							   start, eol);
 			start = eol + 1;
 			line_number++;
@@ -1955,6 +1988,7 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 		o->safe_object_check = 0;
 
 
+	free_fsck_packed_ref_entries(entries, entry_nr);
 	return ret;
 }
 

refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 7386e6bfce..d83ce2838f 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -13,6 +13,7 @@
 #include "../iterator.h"
 #include "../lockfile.h"
 #include "../chdir-notify.h"
+#include "../packfile.h"
 #include "../statinfo.h"
 #include "../worktree.h"
 #include "../wrapper.h"
@@ -1933,6 +1934,52 @@ static int packed_fsck_ref_main_line(struct fsck_options *o,
 	return ret;
 }
 
+static int packed_fsck_ref_oid(struct fsck_options *o, struct ref_store *ref_store,
+			       struct fsck_packed_ref_entry **entries, int nr)
+{
+	struct strbuf packed_entry = STRBUF_INIT;
+	struct fsck_ref_report report = { 0 };
+	struct object *obj;
+	int ret = 0;
+
+	for (int i = 0; i < nr; i++) {
+		struct fsck_packed_ref_entry *entry = entries[i];
+
+		strbuf_release(&packed_entry);
+		strbuf_addf(&packed_entry, "packed-refs line %d", entry->line_number);
+		report.path = packed_entry.buf;
+
+		if (is_promisor_object(ref_store->repo, &entry->oid))
+			continue;
+
+		obj = parse_object(ref_store->repo, &entry->oid);
+		if (!obj) {
+			ret |= fsck_report_ref(o, &report,
+					       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+					       "'%s' is not a valid object",
+					       oid_to_hex(&entry->oid));
+		}
+		if (entry->has_peeled) {
+			strbuf_reset(&packed_entry);
+			strbuf_addf(&packed_entry, "packed-refs line %d",
+				    entry->line_number + 1);
+			report.path = packed_entry.buf;
+
+			obj = parse_object(ref_store->repo, &entry->peeled);
+			if (!obj) {
+				ret |= fsck_report_ref(o, &report,
+						       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+						       "'%s' is not a valid object",
+						       oid_to_hex(&entry->peeled));
+			}
+		}
+
+	}
+
+	strbuf_release(&packed_entry);
+	return ret;
+}
+
 static int packed_fsck_ref_content(struct fsck_options *o,
 				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
@@ -1986,7 +2033,8 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 	 */
 	if (ret)
 		o->safe_object_check = 0;
-
+	else
+		ret |= packed_fsck_ref_oid(o, ref_store, entries, entry_nr);
 
 	free_fsck_packed_ref_entries(entries, entry_nr);
 	return ret;
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 7e8b329425..faa7c80356 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -730,4 +730,39 @@ test_expect_success 'packed-refs content should be checked' '
 	test_cmp expect err
 '
 
+test_expect_success 'packed-refs objects should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	cd repo &&
+	test_commit default &&
+	git tag -a annotated-tag-1 -m tag-1 &&
+
+	tag_1_oid=$(git rev-parse annotated-tag-1) &&
+
+	for non_existing_oid in "$(test_oid 001)" "$(test_oid 002)"
+	do
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s refs/heads/foo\n" "$non_existing_oid" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 2: badPackedRefEntry: '\''$non_existing_oid'\'' is not a valid object
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err || return 1
+	done &&
+
+	for non_existing_oid in "$(test_oid 001)" "$(test_oid 002)"
+	do
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s refs/tags/foo\n" "$tag_1_oid" >>.git/packed-refs &&
+		printf "^$non_existing_oid\n" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 3: badPackedRefEntry: '\''$non_existing_oid'\'' is not a valid object
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err || return 1
+	done
+'
+
 test_done

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index 2a7ec7592e..7a11d35c5e 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -190,6 +190,9 @@
 `packedRefMissingHeader`::
 	(INFO) The "packed-refs" file does not contain the header.
 
+`packedRefUnsorted`::
+	(ERROR) The "packed-refs" file is not sorted.
+
 `refMissingNewline`::
 	(INFO) A loose ref that does not end with newline(LF). As
 	valid implementations of Git never created such a loose ref
diff --git a/fsck.h b/fsck.h
index 4fca304b72..1be7402eb9 100644
--- a/fsck.h
+++ b/fsck.h
@@ -56,6 +56,7 @@ enum fsck_msg_type {
 	FUNC(MISSING_TYPE_ENTRY, ERROR) \
 	FUNC(MULTIPLE_AUTHORS, ERROR) \
 	FUNC(PACKED_REF_ENTRY_NOT_TERMINATED, ERROR) \
+	FUNC(PACKED_REF_UNSORTED, ERROR) \
 	FUNC(TREE_NOT_SORTED, ERROR) \
 	FUNC(UNKNOWN_TYPE, ERROR) \
 	FUNC(ZERO_PADDED_DATE, ERROR) \
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index d83ce2838f..df65fec5a5 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -300,14 +300,8 @@ struct snapshot_record {
 	size_t len;
 };
 
-static int cmp_packed_ref_records(const void *v1, const void *v2,
-				  void *cb_data)
+static int cmp_packed_refname(const char *r1, const char *r2)
 {
-	const struct snapshot *snapshot = cb_data;
-	const struct snapshot_record *e1 = v1, *e2 = v2;
-	const char *r1 = e1->start + snapshot_hexsz(snapshot) + 1;
-	const char *r2 = e2->start + snapshot_hexsz(snapshot) + 1;
-
 	while (1) {
 		if (*r1 == '\n')
 			return *r2 == '\n' ? 0 : -1;
@@ -322,6 +316,17 @@ static int cmp_packed_ref_records(const void *v1, const void *v2,
 	}
 }
 
+static int cmp_packed_ref_records(const void *v1, const void *v2,
+				  void *cb_data)
+{
+	const struct snapshot *snapshot = cb_data;
+	const struct snapshot_record *e1 = v1, *e2 = v2;
+	const char *r1 = e1->start + snapshot_hexsz(snapshot) + 1;
+	const char *r2 = e2->start + snapshot_hexsz(snapshot) + 1;
+
+	return cmp_packed_refname(r1, r2);
+}
+
 /*
  * Compare a snapshot record at `rec` to the specified NUL-terminated
  * refname.
@@ -1775,13 +1780,17 @@ struct fsck_packed_ref_entry {
 	int has_peeled;
 	struct object_id oid;
 	struct object_id peeled;
+
+	struct snapshot_record record;
 };
 
-static struct fsck_packed_ref_entry *create_fsck_packed_ref_entry(int line_number)
+static struct fsck_packed_ref_entry *create_fsck_packed_ref_entry(int line_number,
+								  const char *start)
 {
 	struct fsck_packed_ref_entry *entry = xcalloc(1, sizeof(*entry));
 	entry->line_number = line_number;
 	entry->has_peeled = 0;
+	entry->record.start = start;
 	return entry;
 }
 
@@ -1980,6 +1989,50 @@ static int packed_fsck_ref_oid(struct fsck_options *o, struct ref_store *ref_sto
 	return ret;
 }
 
+static int packed_fsck_ref_sorted(struct fsck_options *o,
+				  struct ref_store *ref_store,
+				  struct fsck_packed_ref_entry **entries,
+				  int nr)
+{
+	size_t hexsz = ref_store->repo->hash_algo->hexsz;
+	struct strbuf packed_entry = STRBUF_INIT;
+	struct fsck_ref_report report = { 0 };
+	struct strbuf refname1 = STRBUF_INIT;
+	struct strbuf refname2 = STRBUF_INIT;
+	int ret = 0;
+
+	for (int i = 1; i < nr; i++) {
+		const char *r1 = entries[i - 1]->record.start + hexsz + 1;
+		const char *r2 = entries[i]->record.start + hexsz + 1;
+
+		if (cmp_packed_refname(r1, r2) >= 0) {
+			const char *err_fmt =
+				"refname '%s' is not less than next refname '%s'";
+			const char *eol;
+			eol = memchr(entries[i - 1]->record.start, '\n',
+				     entries[i - 1]->record.len);
+			strbuf_add(&refname1, r1, eol - r1);
+			eol = memchr(entries[i]->record.start, '\n',
+				     entries[i]->record.len);
+			strbuf_add(&refname2, r2, eol - r2);
+
+			strbuf_addf(&packed_entry, "packed-refs line %d",
+				    entries[i - 1]->line_number);
+			report.path = packed_entry.buf;
+			ret = fsck_report_ref(o, &report,
+					      FSCK_MSG_PACKED_REF_UNSORTED,
+					      err_fmt, refname1.buf, refname2.buf);
+			goto cleanup;
+		}
+	}
+
+cleanup:
+	strbuf_release(&packed_entry);
+	strbuf_release(&refname1);
+	strbuf_release(&refname2);
+	return ret;
+}
+
 static int packed_fsck_ref_content(struct fsck_options *o,
 				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
@@ -2009,7 +2062,7 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 	ALLOC_ARRAY(entries, entry_alloc);
 	while (start < eof) {
 		struct fsck_packed_ref_entry *entry
-			= create_fsck_packed_ref_entry(line_number);
+			= create_fsck_packed_ref_entry(line_number, start);
 		ALLOC_GROW(entries, entry_nr + 1, entry_alloc);
 		entries[entry_nr++] = entry;
 
@@ -2025,16 +2078,19 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 			start = eol + 1;
 			line_number++;
 		}
+		entry->record.len = start - entry->record.start;
 	}
 
 	/*
 	 * If there is anything wrong during the parsing of the "packed-refs"
 	 * file, we should not check the object of the refs.
 	 */
-	if (ret)
+	if (ret) {
 		o->safe_object_check = 0;
-	else
+	} else {
 		ret |= packed_fsck_ref_oid(o, ref_store, entries, entry_nr);
+		ret |= packed_fsck_ref_sorted(o, ref_store, entries, entry_nr);
+	}
 
 	free_fsck_packed_ref_entries(entries, entry_nr);
 	return ret;
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index faa7c80356..800a19e4e6 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -765,4 +765,44 @@ test_expect_success 'packed-refs objects should be checked' '
 	done
 '
 
+test_expect_success 'packed-ref sorted should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	cd repo &&
+	test_commit default &&
+	git branch branch-1 &&
+	git branch branch-2 &&
+	git tag -a annotated-tag-1 -m tag-1 &&
+
+	branch_1_oid=$(git rev-parse branch-1) &&
+	branch_2_oid=$(git rev-parse branch-2) &&
+	tag_1_oid=$(git rev-parse annotated-tag-1) &&
+	tag_1_peeled_oid=$(git rev-parse annotated-tag-1^{}) &&
+
+	refname1="refs/heads/main" &&
+	refname2="refs/heads/foo" &&
+	refname3="refs/tags/foo" &&
+
+	printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+	printf "%s %s\n" "$branch_2_oid" "$refname1" >>.git/packed-refs &&
+	printf "%s %s\n" "$branch_1_oid" "$refname2" >>.git/packed-refs &&
+	test_must_fail git refs verify 2>err &&
+	cat >expect <<-EOF &&
+	error: packed-refs line 2: packedRefUnsorted: refname '\''$refname1'\'' is not less than next refname '\''$refname2'\''
+	EOF
+	rm .git/packed-refs &&
+	test_cmp expect err &&
+
+	printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+	printf "%s %s\n" "$tag_1_oid" "$refname3" >>.git/packed-refs &&
+	printf "^%s\n" "$tag_1_peeled_oid" >>.git/packed-refs &&
+	printf "%s %s\n" "$branch_2_oid" "$refname2" >>.git/packed-refs &&
+	test_must_fail git refs verify 2>err &&
+	cat >expect <<-EOF &&
+	error: packed-refs line 2: packedRefUnsorted: refname '\''$refname3'\'' is not less than next refname '\''$refname2'\''
+	EOF
+	rm .git/packed-refs &&
+	test_cmp expect err
+'
+
 test_done

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 0196c54eb6..a10e52b601 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -902,6 +902,32 @@ static int check_pack_rev_indexes(struct repository *r, int show_progress)
 	return res;
 }
 
+static void fsck_refs(void)
+{
+	struct child_process refs_verify = CHILD_PROCESS_INIT;
+	struct progress *progress = NULL;
+
+	if (show_progress)
+		progress = start_progress(_("Checking ref database"), 1);
+
+	if (verbose)
+		fprintf_ln(stderr, _("Checking ref database"));
+
+	child_process_init(&refs_verify);
+	refs_verify.git_cmd = 1;
+	strvec_pushl(&refs_verify.args, "refs", "verify", NULL);
+	if (verbose)
+		strvec_push(&refs_verify.args, "--verbose");
+	if (check_strict)
+		strvec_push(&refs_verify.args, "--strict");
+
+	if (run_command(&refs_verify))
+		errors_found |= ERROR_REFS;
+
+	display_progress(progress, 1);
+	stop_progress(&progress);
+}
+
 static char const * const fsck_usage[] = {
 	N_("git fsck [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]\n"
 	   "         [--[no-]full] [--strict] [--verbose] [--lost-found]\n"
@@ -967,6 +993,8 @@ int cmd_fsck(int argc,
 	git_config(git_fsck_config, &fsck_obj_options);
 	prepare_repo_settings(the_repository);
 
+	fsck_refs();
+
 	if (connectivity_only) {
 		for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
 		for_each_packed_object(the_repository,

diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index d4a08b823b..cf7a202d0d 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -14,222 +14,229 @@ test_expect_success 'ref name should be checked' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-
-	git commit --allow-empty -m initial &&
-	git checkout -b default-branch &&
-	git tag default-tag &&
-	git tag multi_hierarchy/default-tag &&
-
-	cp $branch_dir_prefix/default-branch $branch_dir_prefix/@ &&
-	git refs verify 2>err &&
-	test_must_be_empty err &&
-	rm $branch_dir_prefix/@ &&
-
-	cp $tag_dir_prefix/default-tag $tag_dir_prefix/tag-1.lock &&
-	git refs verify 2>err &&
-	rm $tag_dir_prefix/tag-1.lock &&
-	test_must_be_empty err &&
-
-	cp $tag_dir_prefix/default-tag $tag_dir_prefix/.lock &&
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: refs/tags/.lock: badRefName: invalid refname format
-	EOF
-	rm $tag_dir_prefix/.lock &&
-	test_cmp expect err &&
-
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname" &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/heads/$refname: badRefName: invalid refname format
-		EOF
-		rm "$branch_dir_prefix/$refname" &&
-		test_cmp expect err || return 1
-	done &&
+	(
+		cd repo &&
 
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		cp $tag_dir_prefix/default-tag "$tag_dir_prefix/$refname" &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/tags/$refname: badRefName: invalid refname format
-		EOF
-		rm "$tag_dir_prefix/$refname" &&
-		test_cmp expect err || return 1
-	done &&
+		git commit --allow-empty -m initial &&
+		git checkout -b default-branch &&
+		git tag default-tag &&
+		git tag multi_hierarchy/default-tag &&
 
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		cp $tag_dir_prefix/multi_hierarchy/default-tag "$tag_dir_prefix/multi_hierarchy/$refname" &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/tags/multi_hierarchy/$refname: badRefName: invalid refname format
-		EOF
-		rm "$tag_dir_prefix/multi_hierarchy/$refname" &&
-		test_cmp expect err || return 1
-	done &&
-
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		mkdir "$branch_dir_prefix/$refname" &&
-		cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname/default-branch" &&
+		cp $branch_dir_prefix/default-branch $branch_dir_prefix/@ &&
+		git refs verify 2>err &&
+		test_must_be_empty err &&
+		rm $branch_dir_prefix/@ &&
+
+		cp $tag_dir_prefix/default-tag $tag_dir_prefix/tag-1.lock &&
+		git refs verify 2>err &&
+		rm $tag_dir_prefix/tag-1.lock &&
+		test_must_be_empty err &&
+
+		cp $tag_dir_prefix/default-tag $tag_dir_prefix/.lock &&
 		test_must_fail git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: refs/heads/$refname/default-branch: badRefName: invalid refname format
+		error: refs/tags/.lock: badRefName: invalid refname format
 		EOF
-		rm -r "$branch_dir_prefix/$refname" &&
-		test_cmp expect err || return 1
-	done
+		rm $tag_dir_prefix/.lock &&
+		test_cmp expect err &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/$refname: badRefName: invalid refname format
+			EOF
+			rm "$branch_dir_prefix/$refname" &&
+			test_cmp expect err || return 1
+		done &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			cp $tag_dir_prefix/default-tag "$tag_dir_prefix/$refname" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/tags/$refname: badRefName: invalid refname format
+			EOF
+			rm "$tag_dir_prefix/$refname" &&
+			test_cmp expect err || return 1
+		done &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			cp $tag_dir_prefix/multi_hierarchy/default-tag "$tag_dir_prefix/multi_hierarchy/$refname" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/tags/multi_hierarchy/$refname: badRefName: invalid refname format
+			EOF
+			rm "$tag_dir_prefix/multi_hierarchy/$refname" &&
+			test_cmp expect err || return 1
+		done &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			mkdir "$branch_dir_prefix/$refname" &&
+			cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname/default-branch" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/$refname/default-branch: badRefName: invalid refname format
+			EOF
+			rm -r "$branch_dir_prefix/$refname" &&
+			test_cmp expect err || return 1
+		done
+	)
 '
 
 test_expect_success 'ref name check should be adapted into fsck messages' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
-	cd repo &&
-	git commit --allow-empty -m initial &&
-	git checkout -b branch-1 &&
-
-	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/.branch-1 &&
-	git -c fsck.badRefName=warn refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/.branch-1: badRefName: invalid refname format
-	EOF
-	rm $branch_dir_prefix/.branch-1 &&
-	test_cmp expect err &&
-
-	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
+	(
+		cd repo &&
+		git commit --allow-empty -m initial &&
+		git checkout -b branch-1 &&
+
+		cp $branch_dir_prefix/branch-1 $branch_dir_prefix/.branch-1 &&
+		git -c fsck.badRefName=warn refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/.branch-1: badRefName: invalid refname format
+		EOF
+		rm $branch_dir_prefix/.branch-1 &&
+		test_cmp expect err &&
+
+		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
+	)
 '
 
 test_expect_success 'ref name check should work for multiple worktrees' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-
-	cd repo &&
-	test_commit initial &&
-	git checkout -b branch-1 &&
-	test_commit second &&
-	git checkout -b branch-2 &&
-	test_commit third &&
-	git checkout -b branch-3 &&
-	git worktree add ./worktree-1 branch-1 &&
-	git worktree add ./worktree-2 branch-2 &&
-	worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
-	worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
-
-	(
-		cd worktree-1 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-3
-	) &&
 	(
-		cd worktree-2 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-3
-	) &&
-
-	cp $worktree1_refdir_prefix/branch-4 $worktree1_refdir_prefix/'\'' branch-5'\'' &&
-	cp $worktree2_refdir_prefix/branch-4 $worktree2_refdir_prefix/'\''~branch-6'\'' &&
-
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
-	error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
-	EOF
-	sort err >sorted_err &&
-	test_cmp expect sorted_err &&
-
-	for worktree in "worktree-1" "worktree-2"
-	do
+		cd repo &&
+		test_commit initial &&
+		git checkout -b branch-1 &&
+		test_commit second &&
+		git checkout -b branch-2 &&
+		test_commit third &&
+		git checkout -b branch-3 &&
+		git worktree add ./worktree-1 branch-1 &&
+		git worktree add ./worktree-2 branch-2 &&
+		worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
+		worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
+
 		(
-			cd $worktree &&
-			test_must_fail git refs verify 2>err &&
-			cat >expect <<-EOF &&
-			error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
-			error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
-			EOF
-			sort err >sorted_err &&
-			test_cmp expect sorted_err || return 1
-		)
-	done
+			cd worktree-1 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-3
+		) &&
+		(
+			cd worktree-2 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-3
+		) &&
+
+		cp $worktree1_refdir_prefix/branch-4 $worktree1_refdir_prefix/'\'' branch-5'\'' &&
+		cp $worktree2_refdir_prefix/branch-4 $worktree2_refdir_prefix/'\''~branch-6'\'' &&
+
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
+		error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
+		EOF
+		sort err >sorted_err &&
+		test_cmp expect sorted_err &&
+
+		for worktree in "worktree-1" "worktree-2"
+		do
+			(
+				cd $worktree &&
+				test_must_fail git refs verify 2>err &&
+				cat >expect <<-EOF &&
+				error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
+				error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
+				EOF
+				sort err >sorted_err &&
+				test_cmp expect sorted_err || return 1
+			)
+		done
+	)
 '
 
 test_expect_success 'regular ref content should be checked (individual)' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
 
-	git refs verify 2>err &&
-	test_must_be_empty err &&
+		git refs verify 2>err &&
+		test_must_be_empty err &&
 
-	for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$branch_dir_prefix/branch-bad &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/heads/branch-bad: badRefContent: $bad_content
-		EOF
-		rm $branch_dir_prefix/branch-bad &&
-		test_cmp expect err || return 1
-	done &&
+		for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$branch_dir_prefix/branch-bad &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/branch-bad: badRefContent: $bad_content
+			EOF
+			rm $branch_dir_prefix/branch-bad &&
+			test_cmp expect err || return 1
+		done &&
 
-	for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$branch_dir_prefix/a/b/branch-bad &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/heads/a/b/branch-bad: badRefContent: $bad_content
-		EOF
-		rm $branch_dir_prefix/a/b/branch-bad &&
-		test_cmp expect err || return 1
-	done &&
-
-	printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	rm $branch_dir_prefix/branch-no-newline &&
-	test_cmp expect err &&
-
-	for trailing_content in " garbage" "    more garbage"
-	do
-		printf "%s" "$(git rev-parse main)$trailing_content" >$branch_dir_prefix/branch-garbage &&
+		for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$branch_dir_prefix/a/b/branch-bad &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/a/b/branch-bad: badRefContent: $bad_content
+			EOF
+			rm $branch_dir_prefix/a/b/branch-bad &&
+			test_cmp expect err || return 1
+		done &&
+
+		printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
 		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\''$trailing_content'\''
+		warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
 		EOF
-		rm $branch_dir_prefix/branch-garbage &&
-		test_cmp expect err || return 1
-	done &&
+		rm $branch_dir_prefix/branch-no-newline &&
+		test_cmp expect err &&
 
-	printf "%s\n\n\n" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
+		for trailing_content in " garbage" "    more garbage"
+		do
+			printf "%s" "$(git rev-parse main)$trailing_content" >$branch_dir_prefix/branch-garbage &&
+			git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\''$trailing_content'\''
+			EOF
+			rm $branch_dir_prefix/branch-garbage &&
+			test_cmp expect err || return 1
+		done &&
 
+		printf "%s\n\n\n" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
 
-	'\''
-	EOF
-	rm $branch_dir_prefix/branch-garbage-special &&
-	test_cmp expect err &&
 
-	printf "%s\n\n\n  garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
+		'\''
+		EOF
+		rm $branch_dir_prefix/branch-garbage-special &&
+		test_cmp expect err &&
+
+		printf "%s\n\n\n  garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
 
 
-	  garbage'\''
-	EOF
-	rm $branch_dir_prefix/branch-garbage-special &&
-	test_cmp expect err
+		  garbage'\''
+		EOF
+		rm $branch_dir_prefix/branch-garbage-special &&
+		test_cmp expect err
+	)
 '
 
 test_expect_success 'regular ref content should be checked (aggregate)' '
@@ -237,99 +244,103 @@ test_expect_success 'regular ref content should be checked (aggregate)' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	bad_content_1=$(git rev-parse main)x &&
-	bad_content_2=xfsazqfxcadas &&
-	bad_content_3=Xfsazqfxcadas &&
-	printf "%s" $bad_content_1 >$tag_dir_prefix/tag-bad-1 &&
-	printf "%s" $bad_content_2 >$tag_dir_prefix/tag-bad-2 &&
-	printf "%s" $bad_content_3 >$branch_dir_prefix/a/b/branch-bad &&
-	printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
-	printf "%s garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage &&
-
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: refs/heads/a/b/branch-bad: badRefContent: $bad_content_3
-	error: refs/tags/tag-bad-1: badRefContent: $bad_content_1
-	error: refs/tags/tag-bad-2: badRefContent: $bad_content_2
-	warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
-	warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	sort err >sorted_err &&
-	test_cmp expect sorted_err
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		bad_content_1=$(git rev-parse main)x &&
+		bad_content_2=xfsazqfxcadas &&
+		bad_content_3=Xfsazqfxcadas &&
+		printf "%s" $bad_content_1 >$tag_dir_prefix/tag-bad-1 &&
+		printf "%s" $bad_content_2 >$tag_dir_prefix/tag-bad-2 &&
+		printf "%s" $bad_content_3 >$branch_dir_prefix/a/b/branch-bad &&
+		printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
+		printf "%s garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage &&
+
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: refs/heads/a/b/branch-bad: badRefContent: $bad_content_3
+		error: refs/tags/tag-bad-1: badRefContent: $bad_content_1
+		error: refs/tags/tag-bad-2: badRefContent: $bad_content_2
+		warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
+		warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
+		EOF
+		sort err >sorted_err &&
+		test_cmp expect sorted_err
+	)
 '
 
 test_expect_success 'textual symref content should be checked (individual)' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		for good_referent in "refs/heads/branch" "HEAD"
+		do
+			printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
+			git refs verify 2>err &&
+			rm $branch_dir_prefix/branch-good &&
+			test_must_be_empty err || return 1
+		done &&
+
+		for bad_referent in "refs/heads/.branch" "refs/heads/~branch" "refs/heads/?branch"
+		do
+			printf "ref: %s\n" $bad_referent >$branch_dir_prefix/branch-bad &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/branch-bad: badReferentName: points to invalid refname '\''$bad_referent'\''
+			EOF
+			rm $branch_dir_prefix/branch-bad &&
+			test_cmp expect err || return 1
+		done &&
 
-	for good_referent in "refs/heads/branch" "HEAD"
-	do
-		printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
+		printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline &&
 		git refs verify 2>err &&
-		rm $branch_dir_prefix/branch-good &&
-		test_must_be_empty err || return 1
-	done &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
+		EOF
+		rm $branch_dir_prefix/branch-no-newline &&
+		test_cmp expect err &&
 
-	for bad_referent in "refs/heads/.branch" "refs/heads/~branch" "refs/heads/?branch"
-	do
-		printf "ref: %s\n" $bad_referent >$branch_dir_prefix/branch-bad &&
-		test_must_fail git refs verify 2>err &&
+		printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
+		EOF
+		rm $branch_dir_prefix/a/b/branch-trailing-1 &&
+		test_cmp expect err &&
+
+		printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: refs/heads/branch-bad: badReferentName: points to invalid refname '\''$bad_referent'\''
+		warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
 		EOF
-		rm $branch_dir_prefix/branch-bad &&
-		test_cmp expect err || return 1
-	done &&
-
-	printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	rm $branch_dir_prefix/branch-no-newline &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-trailing-1 &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-trailing-2 &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-trailing-3 &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-complicated &&
-	test_cmp expect err
+		rm $branch_dir_prefix/a/b/branch-trailing-2 &&
+		test_cmp expect err &&
+
+		printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
+		EOF
+		rm $branch_dir_prefix/a/b/branch-trailing-3 &&
+		test_cmp expect err &&
+
+		printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
+		EOF
+		rm $branch_dir_prefix/a/b/branch-complicated &&
+		test_cmp expect err
+	)
 '
 
 test_expect_success 'textual symref content should be checked (aggregate)' '
@@ -337,32 +348,34 @@ test_expect_success 'textual symref content should be checked (aggregate)' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	printf "ref: refs/heads/branch\n" >$branch_dir_prefix/branch-good &&
-	printf "ref: HEAD\n" >$branch_dir_prefix/branch-head &&
-	printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline-1 &&
-	printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
-	printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
-	printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
-	printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
-	printf "ref: refs/heads/.branch\n" >$branch_dir_prefix/branch-bad-1 &&
-
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: refs/heads/branch-bad-1: badReferentName: points to invalid refname '\''refs/heads/.branch'\''
-	warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/branch-no-newline-1: refMissingNewline: misses LF at the end
-	EOF
-	sort err >sorted_err &&
-	test_cmp expect sorted_err
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		printf "ref: refs/heads/branch\n" >$branch_dir_prefix/branch-good &&
+		printf "ref: HEAD\n" >$branch_dir_prefix/branch-head &&
+		printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline-1 &&
+		printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
+		printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
+		printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
+		printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
+		printf "ref: refs/heads/.branch\n" >$branch_dir_prefix/branch-bad-1 &&
+
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: refs/heads/branch-bad-1: badReferentName: points to invalid refname '\''refs/heads/.branch'\''
+		warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/branch-no-newline-1: refMissingNewline: misses LF at the end
+		EOF
+		sort err >sorted_err &&
+		test_cmp expect sorted_err
+	)
 '
 
 test_expect_success 'the target of the textual symref should be checked' '
@@ -370,28 +383,30 @@ test_expect_success 'the target of the textual symref should be checked' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	for good_referent in "refs/heads/branch" "HEAD" "refs/tags/tag"
-	do
-		printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
-		git refs verify 2>err &&
-		rm $branch_dir_prefix/branch-good &&
-		test_must_be_empty err || return 1
-	done &&
-
-	for nonref_referent in "refs-back/heads/branch" "refs-back/tags/tag" "reflogs/refs/heads/branch"
-	do
-		printf "ref: %s\n" $nonref_referent >$branch_dir_prefix/branch-bad-1 &&
-		git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		warning: refs/heads/branch-bad-1: symrefTargetIsNotARef: points to non-ref target '\''$nonref_referent'\''
-		EOF
-		rm $branch_dir_prefix/branch-bad-1 &&
-		test_cmp expect err || return 1
-	done
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		for good_referent in "refs/heads/branch" "HEAD" "refs/tags/tag"
+		do
+			printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
+			git refs verify 2>err &&
+			rm $branch_dir_prefix/branch-good &&
+			test_must_be_empty err || return 1
+		done &&
+
+		for nonref_referent in "refs-back/heads/branch" "refs-back/tags/tag" "reflogs/refs/heads/branch"
+		do
+			printf "ref: %s\n" $nonref_referent >$branch_dir_prefix/branch-bad-1 &&
+			git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: refs/heads/branch-bad-1: symrefTargetIsNotARef: points to non-ref target '\''$nonref_referent'\''
+			EOF
+			rm $branch_dir_prefix/branch-bad-1 &&
+			test_cmp expect err || return 1
+		done
+	)
 '
 
 test_expect_success SYMLINKS 'symlink symref content should be checked' '
@@ -399,201 +414,207 @@ test_expect_success SYMLINKS 'symlink symref content should be checked' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	ln -sf ./main $branch_dir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $branch_dir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../logs/branch-escape $branch_dir_prefix/branch-symbolic &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
-	warning: refs/heads/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
-	EOF
-	rm $branch_dir_prefix/branch-symbolic &&
-	test_cmp expect err &&
-
-	ln -sf ./"branch   " $branch_dir_prefix/branch-symbolic-bad &&
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic-bad: symlinkRef: use deprecated symbolic link for symref
-	error: refs/heads/branch-symbolic-bad: badReferentName: points to invalid refname '\''refs/heads/branch   '\''
-	EOF
-	rm $branch_dir_prefix/branch-symbolic-bad &&
-	test_cmp expect err &&
-
-	ln -sf ./".tag" $tag_dir_prefix/tag-symbolic-1 &&
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/tags/tag-symbolic-1: symlinkRef: use deprecated symbolic link for symref
-	error: refs/tags/tag-symbolic-1: badReferentName: points to invalid refname '\''refs/tags/.tag'\''
-	EOF
-	rm $tag_dir_prefix/tag-symbolic-1 &&
-	test_cmp expect err
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		ln -sf ./main $branch_dir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
+		EOF
+		rm $branch_dir_prefix/branch-symbolic-good &&
+		test_cmp expect err &&
+
+		ln -sf ../../logs/branch-escape $branch_dir_prefix/branch-symbolic &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
+		warning: refs/heads/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
+		EOF
+		rm $branch_dir_prefix/branch-symbolic &&
+		test_cmp expect err &&
+
+		ln -sf ./"branch   " $branch_dir_prefix/branch-symbolic-bad &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-symbolic-bad: symlinkRef: use deprecated symbolic link for symref
+		error: refs/heads/branch-symbolic-bad: badReferentName: points to invalid refname '\''refs/heads/branch   '\''
+		EOF
+		rm $branch_dir_prefix/branch-symbolic-bad &&
+		test_cmp expect err &&
+
+		ln -sf ./".tag" $tag_dir_prefix/tag-symbolic-1 &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/tags/tag-symbolic-1: symlinkRef: use deprecated symbolic link for symref
+		error: refs/tags/tag-symbolic-1: badReferentName: points to invalid refname '\''refs/tags/.tag'\''
+		EOF
+		rm $tag_dir_prefix/tag-symbolic-1 &&
+		test_cmp expect err
+	)
 '
 
 test_expect_success SYMLINKS 'symlink symref content should be checked (worktree)' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-	cd repo &&
-	test_commit default &&
-	git branch branch-1 &&
-	git branch branch-2 &&
-	git branch branch-3 &&
-	git worktree add ./worktree-1 branch-2 &&
-	git worktree add ./worktree-2 branch-3 &&
-	main_worktree_refdir_prefix=.git/refs/heads &&
-	worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
-	worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
-
 	(
-		cd worktree-1 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
-	(
-		cd worktree-2 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
-
-	ln -sf ../../../../refs/heads/good-branch $worktree1_refdir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $worktree1_refdir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../../../worktrees/worktree-1/good-branch $worktree2_refdir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-2/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $worktree2_refdir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../worktrees/worktree-2/good-branch $main_worktree_refdir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $main_worktree_refdir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../../../logs/branch-escape $worktree1_refdir_prefix/branch-symbolic &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
-	warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
-	EOF
-	rm $worktree1_refdir_prefix/branch-symbolic &&
-	test_cmp expect err &&
-
-	for bad_referent_name in ".tag" "branch   "
-	do
-		ln -sf ./"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git branch branch-3 &&
+		git worktree add ./worktree-1 branch-2 &&
+		git worktree add ./worktree-2 branch-3 &&
+		main_worktree_refdir_prefix=.git/refs/heads &&
+		worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
+		worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
+
+		(
+			cd worktree-1 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+		(
+			cd worktree-2 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+
+		ln -sf ../../../../refs/heads/good-branch $worktree1_refdir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-1/refs/worktree/$bad_referent_name'\''
+		warning: worktrees/worktree-1/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
 		EOF
-		rm $worktree1_refdir_prefix/bad-symbolic &&
+		rm $worktree1_refdir_prefix/branch-symbolic-good &&
 		test_cmp expect err &&
 
-		ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		ln -sf ../../../../worktrees/worktree-1/good-branch $worktree2_refdir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+		warning: worktrees/worktree-2/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
 		EOF
-		rm $worktree1_refdir_prefix/bad-symbolic &&
+		rm $worktree2_refdir_prefix/branch-symbolic-good &&
 		test_cmp expect err &&
 
-		ln -sf ./"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		ln -sf ../../worktrees/worktree-2/good-branch $main_worktree_refdir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-2/refs/worktree/$bad_referent_name'\''
+		warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
 		EOF
-		rm $worktree2_refdir_prefix/bad-symbolic &&
+		rm $main_worktree_refdir_prefix/branch-symbolic-good &&
 		test_cmp expect err &&
 
-		ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		ln -sf ../../../../logs/branch-escape $worktree1_refdir_prefix/branch-symbolic &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+		warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
+		warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
 		EOF
-		rm $worktree2_refdir_prefix/bad-symbolic &&
-		test_cmp expect err || return 1
-	done
+		rm $worktree1_refdir_prefix/branch-symbolic &&
+		test_cmp expect err &&
+
+		for bad_referent_name in ".tag" "branch   "
+		do
+			ln -sf ./"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-1/refs/worktree/$bad_referent_name'\''
+			EOF
+			rm $worktree1_refdir_prefix/bad-symbolic &&
+			test_cmp expect err &&
+
+			ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+			EOF
+			rm $worktree1_refdir_prefix/bad-symbolic &&
+			test_cmp expect err &&
+
+			ln -sf ./"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-2/refs/worktree/$bad_referent_name'\''
+			EOF
+			rm $worktree2_refdir_prefix/bad-symbolic &&
+			test_cmp expect err &&
+
+			ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+			EOF
+			rm $worktree2_refdir_prefix/bad-symbolic &&
+			test_cmp expect err || return 1
+		done
+	)
 '
 
 test_expect_success 'ref content checks should work with worktrees' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-	cd repo &&
-	test_commit default &&
-	git branch branch-1 &&
-	git branch branch-2 &&
-	git branch branch-3 &&
-	git worktree add ./worktree-1 branch-2 &&
-	git worktree add ./worktree-2 branch-3 &&
-	worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
-	worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
-
 	(
-		cd worktree-1 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
-	(
-		cd worktree-2 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git branch branch-3 &&
+		git worktree add ./worktree-1 branch-2 &&
+		git worktree add ./worktree-2 branch-3 &&
+		worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
+		worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
 
-	for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$worktree1_refdir_prefix/bad-branch-1 &&
-		test_must_fail git refs verify 2>err &&
+		(
+			cd worktree-1 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+		(
+			cd worktree-2 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+
+		for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$worktree1_refdir_prefix/bad-branch-1 &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: worktrees/worktree-1/refs/worktree/bad-branch-1: badRefContent: $bad_content
+			EOF
+			rm $worktree1_refdir_prefix/bad-branch-1 &&
+			test_cmp expect err || return 1
+		done &&
+
+		for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$worktree2_refdir_prefix/bad-branch-2 &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: worktrees/worktree-2/refs/worktree/bad-branch-2: badRefContent: $bad_content
+			EOF
+			rm $worktree2_refdir_prefix/bad-branch-2 &&
+			test_cmp expect err || return 1
+		done &&
+
+		printf "%s" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-no-newline &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: worktrees/worktree-1/refs/worktree/bad-branch-1: badRefContent: $bad_content
+		warning: worktrees/worktree-1/refs/worktree/branch-no-newline: refMissingNewline: misses LF at the end
 		EOF
-		rm $worktree1_refdir_prefix/bad-branch-1 &&
-		test_cmp expect err || return 1
-	done &&
+		rm $worktree1_refdir_prefix/branch-no-newline &&
+		test_cmp expect err &&
 
-	for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$worktree2_refdir_prefix/bad-branch-2 &&
-		test_must_fail git refs verify 2>err &&
+		printf "%s garbage" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-garbage &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: worktrees/worktree-2/refs/worktree/bad-branch-2: badRefContent: $bad_content
+		warning: worktrees/worktree-1/refs/worktree/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
 		EOF
-		rm $worktree2_refdir_prefix/bad-branch-2 &&
-		test_cmp expect err || return 1
-	done &&
-
-	printf "%s" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-no-newline &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	rm $worktree1_refdir_prefix/branch-no-newline &&
-	test_cmp expect err &&
-
-	printf "%s garbage" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-garbage &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
-	EOF
-	rm $worktree1_refdir_prefix/branch-garbage &&
-	test_cmp expect err
+		rm $worktree1_refdir_prefix/branch-garbage &&
+		test_cmp expect err
+	)
 '
 
 test_done

builtin/refs.c, worktree.c, worktree.h

diff --git a/builtin/refs.c b/builtin/refs.c
index a29f195834..55ff5dae11 100644
--- a/builtin/refs.c
+++ b/builtin/refs.c
@@ -88,7 +88,7 @@ static int cmd_refs_verify(int argc, const char **argv, const char *prefix,
 	git_config(git_fsck_config, &fsck_refs_options);
 	prepare_repo_settings(the_repository);
 
-	worktrees = get_worktrees();
+	worktrees = get_worktrees_without_reading_head();
 	for (size_t i = 0; worktrees[i]; i++)
 		ret |= refs_fsck(get_worktree_ref_store(worktrees[i]),
 				 &fsck_refs_options, worktrees[i]);
diff --git a/worktree.c b/worktree.c
index 248bbb39d4..89b7d86cef 100644
--- a/worktree.c
+++ b/worktree.c
@@ -175,6 +175,11 @@ struct worktree **get_worktrees(void)
 	return get_worktrees_internal(0);
 }
 
+struct worktree **get_worktrees_without_reading_head(void)
+{
+	return get_worktrees_internal(1);
+}
+
 const char *get_worktree_git_dir(const struct worktree *wt)
 {
 	if (!wt)
diff --git a/worktree.h b/worktree.h
index 38145df80f..1ba4a161a0 100644
--- a/worktree.h
+++ b/worktree.h
@@ -30,6 +30,12 @@ struct worktree {
  */
 struct worktree **get_worktrees(void);
 
+/*
+ * Like `get_worktrees`, but does not read HEAD. This is useful when checking
+ * the consistency, as reading HEAD may not be necessary.
+ */
+struct worktree **get_worktrees_without_reading_head(void);
+
 /*
  * Returns 1 if linked worktrees exist, 0 otherwise.
  */

refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index a7b6f74b6e..6401cecd5f 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -4,6 +4,7 @@
 #include "../git-compat-util.h"
 #include "../config.h"
 #include "../dir.h"
+#include "../fsck.h"
 #include "../gettext.h"
 #include "../hash.h"
 #include "../hex.h"
@@ -1748,15 +1749,45 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
-static int packed_fsck(struct ref_store *ref_store UNUSED,
-		       struct fsck_options *o UNUSED,
+static int packed_fsck(struct ref_store *ref_store,
+		       struct fsck_options *o,
 		       struct worktree *wt)
 {
+	struct packed_ref_store *refs = packed_downcast(ref_store,
+							REF_STORE_READ, "fsck");
+	int ret = 0;
+	int fd;
 
 	if (!is_main_worktree(wt))
-		return 0;
+		goto cleanup;
 
-	return 0;
+	if (o->verbose)
+		fprintf_ln(stderr, "Checking packed-refs file %s", refs->path);
+
+	fd = open_nofollow(refs->path, O_RDONLY);
+	if (fd < 0) {
+		/*
+		 * If the packed-refs file doesn't exist, there's nothing
+		 * to check.
+		 */
+		if (errno == ENOENT)
+			goto cleanup;
+
+		if (errno == ELOOP) {
+			struct fsck_ref_report report = { 0 };
+			report.path = "packed-refs";
+			ret = fsck_report_ref(o, &report,
+					      FSCK_MSG_BAD_REF_FILETYPE,
+					      "not a regular file");
+			goto cleanup;
+		}
+
+		ret = error_errno(_("unable to open %s"), refs->path);
+		goto cleanup;
+	}
+
+cleanup:
+	return ret;
 }
 
 struct ref_storage_be refs_be_packed = {
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index cf7a202d0d..42c8d4ca1e 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -617,4 +617,26 @@ test_expect_success 'ref content checks should work with worktrees' '
 	)
 '
 
+test_expect_success SYMLINKS 'the filetype of packed-refs should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git branch branch-3 &&
+		git pack-refs --all &&
+
+		mv .git/packed-refs .git/packed-refs-back &&
+		ln -sf packed-refs-bak .git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs: badRefFiletype: not a regular file
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err
+	)
+'
+
 test_done

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index b14bc44ca4..34375a3143 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -16,6 +16,10 @@
 `badObjectSha1`::
 	(ERROR) An object has a bad sha1.
 
+`badPackedRefHeader`::
+	(ERROR) The "packed-refs" file contains an invalid
+	header.
+
 `badParentSha1`::
 	(ERROR) A commit object has a bad parent sha1.
 
@@ -176,6 +180,13 @@
 `nullSha1`::
 	(WARN) Tree contains entries pointing to a null sha1.
 
+`packedRefEntryNotTerminated`::
+	(ERROR) The "packed-refs" file contains an entry that is
+	not terminated by a newline.
+
+`packedRefMissingHeader`::
+	(INFO) The "packed-refs" file does not contain the header.
+
 `refMissingNewline`::
 	(INFO) A loose ref that does not end with newline(LF). As
 	valid implementations of Git never created such a loose ref
@@ -208,6 +219,11 @@
 `treeNotSorted`::
 	(ERROR) A tree is not properly sorted.
 
+`unknownPackedRefHeader`::
+	(INFO) The "packed-refs" header starts with "# pack-refs with:"
+	but the remaining content is not the same as what `git pack-refs`
+	would write.
+
 `unknownType`::
 	(ERROR) Found an unknown object type.
 
diff --git a/fsck.h b/fsck.h
index a44c231a5f..3107a0093d 100644
--- a/fsck.h
+++ b/fsck.h
@@ -30,6 +30,7 @@ enum fsck_msg_type {
 	FUNC(BAD_EMAIL, ERROR) \
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
+	FUNC(BAD_PACKED_REF_HEADER, ERROR) \
 	FUNC(BAD_PARENT_SHA1, ERROR) \
 	FUNC(BAD_REF_CONTENT, ERROR) \
 	FUNC(BAD_REF_FILETYPE, ERROR) \
@@ -53,6 +54,7 @@ enum fsck_msg_type {
 	FUNC(MISSING_TYPE, ERROR) \
 	FUNC(MISSING_TYPE_ENTRY, ERROR) \
 	FUNC(MULTIPLE_AUTHORS, ERROR) \
+	FUNC(PACKED_REF_ENTRY_NOT_TERMINATED, ERROR) \
 	FUNC(TREE_NOT_SORTED, ERROR) \
 	FUNC(UNKNOWN_TYPE, ERROR) \
 	FUNC(ZERO_PADDED_DATE, ERROR) \
@@ -90,6 +92,8 @@ enum fsck_msg_type {
 	FUNC(REF_MISSING_NEWLINE, INFO) \
 	FUNC(SYMREF_TARGET_IS_NOT_A_REF, INFO) \
 	FUNC(TRAILING_REF_CONTENT, INFO) \
+	FUNC(UNKNOWN_PACKED_REF_HEADER, INFO) \
+	FUNC(PACKED_REF_MISSING_HEADER, INFO) \
 	/* ignored (elevated when requested) */ \
 	FUNC(EXTRA_HEADER_ENTRY, IGNORE)
 
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 6401cecd5f..883189f3a1 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1749,12 +1749,92 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
+static int packed_fsck_ref_next_line(struct fsck_options *o,
+				     struct strbuf *packed_entry, const char *start,
+				     const char *eof, const char **eol)
+{
+	int ret = 0;
+
+	*eol = memchr(start, '\n', eof - start);
+	if (!*eol) {
+		struct fsck_ref_report report = { 0 };
+
+		report.path = packed_entry->buf;
+		ret = fsck_report_ref(o, &report,
+				      FSCK_MSG_PACKED_REF_ENTRY_NOT_TERMINATED,
+				      "'%.*s' is not terminated with a newline",
+				      (int)(eof - start), start);
+
+		/*
+		 * There is no newline but we still want to parse it to the end of
+		 * the buffer.
+		 */
+		*eol = eof;
+	}
+
+	return ret;
+}
+
+static int packed_fsck_ref_header(struct fsck_options *o, const char *start, const char *eol)
+{
+	const char *err_fmt = NULL;
+	int fsck_msg_id = -1;
+
+	if (!starts_with(start, "# pack-refs with:")) {
+		err_fmt = "'%.*s' does not start with '# pack-refs with:'";
+		fsck_msg_id = FSCK_MSG_BAD_PACKED_REF_HEADER;
+	} else if (strncmp(start, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER))) {
+		err_fmt = "'%.*s' is an unknown packed-refs header";
+		fsck_msg_id = FSCK_MSG_UNKNOWN_PACKED_REF_HEADER;
+	}
+
+	if (err_fmt && fsck_msg_id >= 0) {
+		struct fsck_ref_report report = { 0 };
+		report.path = "packed-refs.header";
+
+		return fsck_report_ref(o, &report, fsck_msg_id, err_fmt,
+				       (int)(eol - start), start);
+
+	}
+
+	return 0;
+}
+
+static int packed_fsck_ref_content(struct fsck_options *o,
+				   const char *start, const char *eof)
+{
+	struct strbuf packed_entry = STRBUF_INIT;
+	int line_number = 1;
+	const char *eol;
+	int ret = 0;
+
+	strbuf_addf(&packed_entry, "packed-refs line %d", line_number);
+	ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
+	if (*start == '#') {
+		ret |= packed_fsck_ref_header(o, start, eol);
+
+		start = eol + 1;
+		line_number++;
+	} else {
+		struct fsck_ref_report report = { 0 };
+		report.path = "packed-refs";
+
+		ret |= fsck_report_ref(o, &report,
+				       FSCK_MSG_PACKED_REF_MISSING_HEADER,
+				       "missing header line");
+	}
+
+	strbuf_release(&packed_entry);
+	return ret;
+}
+
 static int packed_fsck(struct ref_store *ref_store,
 		       struct fsck_options *o,
 		       struct worktree *wt)
 {
 	struct packed_ref_store *refs = packed_downcast(ref_store,
 							REF_STORE_READ, "fsck");
+	struct strbuf packed_ref_content = STRBUF_INIT;
 	int ret = 0;
 	int fd;
 
@@ -1786,7 +1866,16 @@ static int packed_fsck(struct ref_store *ref_store,
 		goto cleanup;
 	}
 
+	if (strbuf_read(&packed_ref_content, fd, 0) < 0) {
+		ret = error_errno(_("unable to read %s"), refs->path);
+		goto cleanup;
+	}
+
+	ret = packed_fsck_ref_content(o, packed_ref_content.buf,
+				      packed_ref_content.buf + packed_ref_content.len);
+
 cleanup:
+	strbuf_release(&packed_ref_content);
 	return ret;
 }
 
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 42c8d4ca1e..a7b46b6cb9 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -639,4 +639,50 @@ test_expect_success SYMLINKS 'the filetype of packed-refs should be checked' '
 	)
 '
 
+test_expect_success 'packed-refs header should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+
+		git refs verify 2>err &&
+		test_must_be_empty err &&
+
+		printf "$(git rev-parse main) refs/heads/main\n" >.git/packed-refs &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: packed-refs: packedRefMissingHeader: missing header line
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err &&
+
+		for bad_header in "# pack-refs wit: peeled fully-peeled sorted " \
+				"# pack-refs with traits: peeled fully-peeled sorted " \
+				"# pack-refs with a: peeled fully-peeled"
+		do
+			printf "%s\n" "$bad_header" >.git/packed-refs &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: packed-refs.header: badPackedRefHeader: '\''$bad_header'\'' does not start with '\''# pack-refs with:'\''
+			EOF
+			rm .git/packed-refs &&
+			test_cmp expect err || return 1
+		done &&
+
+		for unknown_header in "# pack-refs with: peeled fully-peeled sorted garbage" \
+				"# pack-refs with: peeled" \
+				"# pack-refs with: peeled peeled-fully sort"
+		do
+			printf "%s\n" "$unknown_header" >.git/packed-refs &&
+			git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: packed-refs.header: unknownPackedRefHeader: '\''$unknown_header'\'' is an unknown packed-refs header
+			EOF
+			rm .git/packed-refs &&
+			test_cmp expect err || return 1
+		done
+	)
+'
+
 test_done

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 883189f3a1..870c8e7aaa 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -494,6 +494,22 @@ static void verify_buffer_safe(struct snapshot *snapshot)
 				 last_line, eof - last_line);
 }
 
+/*
+ * When parsing the "packed-refs" file, we will parse it line by line.
+ * Because we know the start pointer of the refname and the next
+ * newline pointer, we could calculate the length of the refname by
+ * subtracting the two pointers. However, there is a corner case where
+ * the refname contains corrupted embedded NUL characters. And
+ * `check_refname_format()` will not catch this when the truncated
+ * refname is still a valid refname. To prevent this, we need to check
+ * whether the refname contains the NUL characters.
+ */
+static int refname_contains_nul(struct strbuf *refname)
+{
+	const char *pos = memchr(refname->buf, '\0', refname->len + 1);
+	return pos < refname->buf + refname->len;
+}
+
 #define SMALL_FILE_SIZE (32*1024)
 
 /*
@@ -895,6 +911,9 @@ static int next_record(struct packed_ref_iterator *iter)
 	strbuf_add(&iter->refname_buf, p, eol - p);
 	iter->base.refname = iter->refname_buf.buf;
 
+	if (refname_contains_nul(&iter->refname_buf))
+		die("packed refname contains embedded NULL: %s", iter->base.refname);
+
 	if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) {
 		if (!refname_is_safe(iter->base.refname))
 			die("packed refname is dangerous: %s",

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index 34375a3143..2a7ec7592e 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -16,6 +16,9 @@
 `badObjectSha1`::
 	(ERROR) An object has a bad sha1.
 
+`badPackedRefEntry`::
+	(ERROR) The "packed-refs" file contains an invalid entry.
+
 `badPackedRefHeader`::
 	(ERROR) The "packed-refs" file contains an invalid
 	header.
diff --git a/fsck.h b/fsck.h
index 3107a0093d..40126242a4 100644
--- a/fsck.h
+++ b/fsck.h
@@ -30,6 +30,7 @@ enum fsck_msg_type {
 	FUNC(BAD_EMAIL, ERROR) \
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
+	FUNC(BAD_PACKED_REF_ENTRY, ERROR) \
 	FUNC(BAD_PACKED_REF_HEADER, ERROR) \
 	FUNC(BAD_PARENT_SHA1, ERROR) \
 	FUNC(BAD_REF_CONTENT, ERROR) \
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 870c8e7aaa..271c740728 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1819,10 +1819,86 @@ static int packed_fsck_ref_header(struct fsck_options *o, const char *start, con
 	return 0;
 }
 
+static int packed_fsck_ref_peeled_line(struct fsck_options *o,
+				       struct ref_store *ref_store,
+				       struct strbuf *packed_entry,
+				       const char *start, const char *eol)
+{
+	struct fsck_ref_report report = { 0 };
+	struct object_id peeled;
+	const char *p;
+
+	report.path = packed_entry->buf;
+
+	start++;
+	if (parse_oid_hex_algop(start, &peeled, &p, ref_store->repo->hash_algo)) {
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "'%.*s' has invalid peeled oid",
+				       (int)(eol - start), start);
+	}
+
+	if (p != eol) {
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "has trailing garbage after peeled oid '%.*s'",
+				       (int)(eol - p), p);
+	}
+
+	return 0;
+}
+
+static int packed_fsck_ref_main_line(struct fsck_options *o,
+				     struct ref_store *ref_store,
+				     struct strbuf *packed_entry,
+				     struct strbuf *refname,
+				     const char *start, const char *eol)
+{
+	struct fsck_ref_report report = { 0 };
+	struct object_id oid;
+	const char *p;
+
+	report.path = packed_entry->buf;
+
+	if (parse_oid_hex_algop(start, &oid, &p, ref_store->repo->hash_algo)) {
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "'%.*s' has invalid oid",
+				       (int)(eol - start), start);
+	}
+
+	if (p == eol || !isspace(*p)) {
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "has no space after oid '%s' but with '%.*s'",
+				       oid_to_hex(&oid), (int)(eol - p), p);
+	}
+
+	p++;
+	strbuf_reset(refname);
+	strbuf_add(refname, p, eol - p);
+	if (refname_contains_nul(refname)) {
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "refname '%s' contains NULL binaries",
+				       refname->buf);
+	}
+
+	if (check_refname_format(refname->buf, 0)) {
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_REF_NAME,
+				       "has bad refname '%s'", refname->buf);
+	}
+
+	return 0;
+}
+
 static int packed_fsck_ref_content(struct fsck_options *o,
+				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
 {
 	struct strbuf packed_entry = STRBUF_INIT;
+	struct strbuf refname = STRBUF_INIT;
 	int line_number = 1;
 	const char *eol;
 	int ret = 0;
@@ -1843,6 +1919,26 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 				       "missing header line");
 	}
 
+	while (start < eof) {
+		strbuf_reset(&packed_entry);
+		strbuf_addf(&packed_entry, "packed-refs line %d", line_number);
+		ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
+		ret |= packed_fsck_ref_main_line(o, ref_store, &packed_entry, &refname, start, eol);
+		start = eol + 1;
+		line_number++;
+		if (start < eof && *start == '^') {
+			strbuf_reset(&packed_entry);
+			strbuf_addf(&packed_entry, "packed-refs line %d", line_number);
+			ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
+			ret |= packed_fsck_ref_peeled_line(o, ref_store, &packed_entry,
+							   start, eol);
+			start = eol + 1;
+			line_number++;
+		}
+	}
+
+	strbuf_release(&packed_entry);
+	strbuf_release(&refname);
 	strbuf_release(&packed_entry);
 	return ret;
 }
@@ -1890,7 +1986,7 @@ static int packed_fsck(struct ref_store *ref_store,
 		goto cleanup;
 	}
 
-	ret = packed_fsck_ref_content(o, packed_ref_content.buf,
+	ret = packed_fsck_ref_content(o, ref_store, packed_ref_content.buf,
 				      packed_ref_content.buf + packed_ref_content.len);
 
 cleanup:
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index a7b46b6cb9..e4b4a58684 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -685,4 +685,46 @@ test_expect_success 'packed-refs header should be checked' '
 	)
 '
 
+test_expect_success 'packed-refs content should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git tag -a annotated-tag-1 -m tag-1 &&
+		git tag -a annotated-tag-2 -m tag-2 &&
+
+		branch_1_oid=$(git rev-parse branch-1) &&
+		branch_2_oid=$(git rev-parse branch-2) &&
+		tag_1_oid=$(git rev-parse annotated-tag-1) &&
+		tag_2_oid=$(git rev-parse annotated-tag-2) &&
+		tag_1_peeled_oid=$(git rev-parse annotated-tag-1^{}) &&
+		tag_2_peeled_oid=$(git rev-parse annotated-tag-2^{}) &&
+		short_oid=$(printf "%s" $tag_1_peeled_oid | cut -c 1-4) &&
+
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s\n" "$short_oid refs/heads/branch-1" >>.git/packed-refs &&
+		printf "%sx\n" "$branch_1_oid" >>.git/packed-refs &&
+		printf "%s   refs/heads/bad-branch\n" "$branch_2_oid" >>.git/packed-refs &&
+		printf "%s refs/heads/branch.\n" "$branch_2_oid" >>.git/packed-refs &&
+		printf "%s refs/tags/annotated-tag-3\n" "$tag_1_oid" >>.git/packed-refs &&
+		printf "^%s\n" "$short_oid" >>.git/packed-refs &&
+		printf "%s refs/tags/annotated-tag-4.\n" "$tag_2_oid" >>.git/packed-refs &&
+		printf "^%s garbage\n" "$tag_2_peeled_oid" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 2: badPackedRefEntry: '\''$short_oid refs/heads/branch-1'\'' has invalid oid
+		error: packed-refs line 3: badPackedRefEntry: has no space after oid '\''$branch_1_oid'\'' but with '\''x'\''
+		error: packed-refs line 4: badRefName: has bad refname '\''  refs/heads/bad-branch'\''
+		error: packed-refs line 5: badRefName: has bad refname '\''refs/heads/branch.'\''
+		error: packed-refs line 7: badPackedRefEntry: '\''$short_oid'\'' has invalid peeled oid
+		error: packed-refs line 8: badRefName: has bad refname '\''refs/tags/annotated-tag-4.'\''
+		error: packed-refs line 9: badPackedRefEntry: has trailing garbage after peeled oid '\'' garbage'\''
+		EOF
+		test_cmp expect err
+	)
+'
+
 test_done

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index 2a7ec7592e..7a11d35c5e 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -190,6 +190,9 @@
 `packedRefMissingHeader`::
 	(INFO) The "packed-refs" file does not contain the header.
 
+`packedRefUnsorted`::
+	(ERROR) The "packed-refs" file is not sorted.
+
 `refMissingNewline`::
 	(INFO) A loose ref that does not end with newline(LF). As
 	valid implementations of Git never created such a loose ref
diff --git a/fsck.h b/fsck.h
index 40126242a4..0d3d1045ae 100644
--- a/fsck.h
+++ b/fsck.h
@@ -56,6 +56,7 @@ enum fsck_msg_type {
 	FUNC(MISSING_TYPE_ENTRY, ERROR) \
 	FUNC(MULTIPLE_AUTHORS, ERROR) \
 	FUNC(PACKED_REF_ENTRY_NOT_TERMINATED, ERROR) \
+	FUNC(PACKED_REF_UNSORTED, ERROR) \
 	FUNC(TREE_NOT_SORTED, ERROR) \
 	FUNC(UNKNOWN_TYPE, ERROR) \
 	FUNC(ZERO_PADDED_DATE, ERROR) \
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 271c740728..b250f987b2 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -300,14 +300,9 @@ struct snapshot_record {
 	size_t len;
 };
 
-static int cmp_packed_ref_records(const void *v1, const void *v2,
-				  void *cb_data)
-{
-	const struct snapshot *snapshot = cb_data;
-	const struct snapshot_record *e1 = v1, *e2 = v2;
-	const char *r1 = e1->start + snapshot_hexsz(snapshot) + 1;
-	const char *r2 = e2->start + snapshot_hexsz(snapshot) + 1;
 
+static int cmp_packed_refname(const char *r1, const char *r2)
+{
 	while (1) {
 		if (*r1 == '\n')
 			return *r2 == '\n' ? 0 : -1;
@@ -322,6 +317,17 @@ static int cmp_packed_ref_records(const void *v1, const void *v2,
 	}
 }
 
+static int cmp_packed_ref_records(const void *v1, const void *v2,
+				  void *cb_data)
+{
+	const struct snapshot *snapshot = cb_data;
+	const struct snapshot_record *e1 = v1, *e2 = v2;
+	const char *r1 = e1->start + snapshot_hexsz(snapshot) + 1;
+	const char *r2 = e2->start + snapshot_hexsz(snapshot) + 1;
+
+	return cmp_packed_refname(r1, r2);
+}
+
 /*
  * Compare a snapshot record at `rec` to the specified NUL-terminated
  * refname.
@@ -1768,6 +1774,28 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
+struct fsck_packed_ref_entry {
+	int line_number;
+
+	struct snapshot_record record;
+};
+
+static struct fsck_packed_ref_entry *create_fsck_packed_ref_entry(int line_number,
+								  const char *start)
+{
+	struct fsck_packed_ref_entry *entry = xcalloc(1, sizeof(*entry));
+	entry->line_number = line_number;
+	entry->record.start = start;
+	return entry;
+}
+
+static void free_fsck_packed_ref_entries(struct fsck_packed_ref_entry **entries, int nr)
+{
+	for (int i = 0; i < nr; i++)
+		free(entries[i]);
+	free(entries);
+}
+
 static int packed_fsck_ref_next_line(struct fsck_options *o,
 				     struct strbuf *packed_entry, const char *start,
 				     const char *eof, const char **eol)
@@ -1893,13 +1921,60 @@ static int packed_fsck_ref_main_line(struct fsck_options *o,
 	return 0;
 }
 
+static int packed_fsck_ref_sorted(struct fsck_options *o,
+				  struct ref_store *ref_store,
+				  struct fsck_packed_ref_entry **entries,
+				  int nr)
+{
+	size_t hexsz = ref_store->repo->hash_algo->hexsz;
+	struct strbuf packed_entry = STRBUF_INIT;
+	struct fsck_ref_report report = { 0 };
+	struct strbuf refname1 = STRBUF_INIT;
+	struct strbuf refname2 = STRBUF_INIT;
+	int ret = 0;
+
+	for (int i = 1; i < nr; i++) {
+		const char *r1 = entries[i - 1]->record.start + hexsz + 1;
+		const char *r2 = entries[i]->record.start + hexsz + 1;
+
+		if (cmp_packed_refname(r1, r2) >= 0) {
+			const char *err_fmt =
+				"refname '%s' is not less than next refname '%s'";
+			const char *eol;
+			eol = memchr(entries[i - 1]->record.start, '\n',
+				     entries[i - 1]->record.len);
+			strbuf_add(&refname1, r1, eol - r1);
+			eol = memchr(entries[i]->record.start, '\n',
+				     entries[i]->record.len);
+			strbuf_add(&refname2, r2, eol - r2);
+
+			strbuf_addf(&packed_entry, "packed-refs line %d",
+				    entries[i - 1]->line_number);
+			report.path = packed_entry.buf;
+			ret = fsck_report_ref(o, &report,
+					      FSCK_MSG_PACKED_REF_UNSORTED,
+					      err_fmt, refname1.buf, refname2.buf);
+			goto cleanup;
+		}
+	}
+
+cleanup:
+	strbuf_release(&packed_entry);
+	strbuf_release(&refname1);
+	strbuf_release(&refname2);
+	return ret;
+}
+
 static int packed_fsck_ref_content(struct fsck_options *o,
 				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
 {
 	struct strbuf packed_entry = STRBUF_INIT;
+	struct fsck_packed_ref_entry **entries;
 	struct strbuf refname = STRBUF_INIT;
+	int entry_alloc = 20;
 	int line_number = 1;
+	int entry_nr = 0;
 	const char *eol;
 	int ret = 0;
 
@@ -1919,7 +1994,13 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 				       "missing header line");
 	}
 
+	ALLOC_ARRAY(entries, entry_alloc);
 	while (start < eof) {
+		struct fsck_packed_ref_entry *entry
+			= create_fsck_packed_ref_entry(line_number, start);
+
+		ALLOC_GROW(entries, entry_nr + 1, entry_alloc);
+		entries[entry_nr++] = entry;
 		strbuf_reset(&packed_entry);
 		strbuf_addf(&packed_entry, "packed-refs line %d", line_number);
 		ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
@@ -1935,11 +2016,16 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 			start = eol + 1;
 			line_number++;
 		}
+		entry->record.len = start - entry->record.start;
 	}
 
+	if (!ret)
+		ret |= packed_fsck_ref_sorted(o, ref_store, entries, entry_nr);
+
 	strbuf_release(&packed_entry);
 	strbuf_release(&refname);
 	strbuf_release(&packed_entry);
+	free_fsck_packed_ref_entries(entries, entry_nr);
 	return ret;
 }
 
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index e4b4a58684..9d802d71a9 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -727,4 +727,42 @@ test_expect_success 'packed-refs content should be checked' '
 	)
 '
 
+test_expect_success 'packed-ref sorted should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git tag -a annotated-tag-1 -m tag-1 &&
+		branch_1_oid=$(git rev-parse branch-1) &&
+		branch_2_oid=$(git rev-parse branch-2) &&
+		tag_1_oid=$(git rev-parse annotated-tag-1) &&
+		tag_1_peeled_oid=$(git rev-parse annotated-tag-1^{}) &&
+		refname1="refs/heads/main" &&
+		refname2="refs/heads/foo" &&
+		refname3="refs/tags/foo" &&
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s %s\n" "$branch_2_oid" "$refname1" >>.git/packed-refs &&
+		printf "%s %s\n" "$branch_1_oid" "$refname2" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 2: packedRefUnsorted: refname '\''$refname1'\'' is not less than next refname '\''$refname2'\''
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err &&
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s %s\n" "$tag_1_oid" "$refname3" >>.git/packed-refs &&
+		printf "^%s\n" "$tag_1_peeled_oid" >>.git/packed-refs &&
+		printf "%s %s\n" "$branch_2_oid" "$refname2" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 2: packedRefUnsorted: refname '\''$refname3'\'' is not less than next refname '\''$refname2'\''
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err
+	)
+'
+
 test_done

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 7a4dcb0716..9a8613d07f 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -905,6 +905,34 @@ static int check_pack_rev_indexes(struct repository *r, int show_progress)
 	return res;
 }
 
+static void fsck_refs(struct repository *r)
+{
+	struct child_process refs_verify = CHILD_PROCESS_INIT;
+	struct progress *progress = NULL;
+	uint64_t progress_num = 1;
+
+	if (show_progress)
+		progress = start_progress(r, _("Checking ref database"),
+					  progress_num);
+
+	if (verbose)
+		fprintf_ln(stderr, _("Checking ref database"));
+
+	child_process_init(&refs_verify);
+	refs_verify.git_cmd = 1;
+	strvec_pushl(&refs_verify.args, "refs", "verify", NULL);
+	if (verbose)
+		strvec_push(&refs_verify.args, "--verbose");
+	if (check_strict)
+		strvec_push(&refs_verify.args, "--strict");
+
+	if (run_command(&refs_verify))
+		errors_found |= ERROR_REFS;
+
+	display_progress(progress, 1);
+	stop_progress(&progress);
+}
+
 static char const * const fsck_usage[] = {
 	N_("git fsck [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]\n"
 	   "         [--[no-]full] [--strict] [--verbose] [--lost-found]\n"
@@ -970,6 +998,8 @@ int cmd_fsck(int argc,
 	git_config(git_fsck_config, &fsck_obj_options);
 	prepare_repo_settings(the_repository);
 
+	fsck_refs(the_repository);
+
 	if (connectivity_only) {
 		for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
 		for_each_packed_object(the_repository,

diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index d4a08b823b..cf7a202d0d 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -14,222 +14,229 @@ test_expect_success 'ref name should be checked' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-
-	git commit --allow-empty -m initial &&
-	git checkout -b default-branch &&
-	git tag default-tag &&
-	git tag multi_hierarchy/default-tag &&
-
-	cp $branch_dir_prefix/default-branch $branch_dir_prefix/@ &&
-	git refs verify 2>err &&
-	test_must_be_empty err &&
-	rm $branch_dir_prefix/@ &&
-
-	cp $tag_dir_prefix/default-tag $tag_dir_prefix/tag-1.lock &&
-	git refs verify 2>err &&
-	rm $tag_dir_prefix/tag-1.lock &&
-	test_must_be_empty err &&
-
-	cp $tag_dir_prefix/default-tag $tag_dir_prefix/.lock &&
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: refs/tags/.lock: badRefName: invalid refname format
-	EOF
-	rm $tag_dir_prefix/.lock &&
-	test_cmp expect err &&
-
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname" &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/heads/$refname: badRefName: invalid refname format
-		EOF
-		rm "$branch_dir_prefix/$refname" &&
-		test_cmp expect err || return 1
-	done &&
+	(
+		cd repo &&
 
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		cp $tag_dir_prefix/default-tag "$tag_dir_prefix/$refname" &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/tags/$refname: badRefName: invalid refname format
-		EOF
-		rm "$tag_dir_prefix/$refname" &&
-		test_cmp expect err || return 1
-	done &&
+		git commit --allow-empty -m initial &&
+		git checkout -b default-branch &&
+		git tag default-tag &&
+		git tag multi_hierarchy/default-tag &&
 
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		cp $tag_dir_prefix/multi_hierarchy/default-tag "$tag_dir_prefix/multi_hierarchy/$refname" &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/tags/multi_hierarchy/$refname: badRefName: invalid refname format
-		EOF
-		rm "$tag_dir_prefix/multi_hierarchy/$refname" &&
-		test_cmp expect err || return 1
-	done &&
-
-	for refname in ".refname-starts-with-dot" "~refname-has-stride"
-	do
-		mkdir "$branch_dir_prefix/$refname" &&
-		cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname/default-branch" &&
+		cp $branch_dir_prefix/default-branch $branch_dir_prefix/@ &&
+		git refs verify 2>err &&
+		test_must_be_empty err &&
+		rm $branch_dir_prefix/@ &&
+
+		cp $tag_dir_prefix/default-tag $tag_dir_prefix/tag-1.lock &&
+		git refs verify 2>err &&
+		rm $tag_dir_prefix/tag-1.lock &&
+		test_must_be_empty err &&
+
+		cp $tag_dir_prefix/default-tag $tag_dir_prefix/.lock &&
 		test_must_fail git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: refs/heads/$refname/default-branch: badRefName: invalid refname format
+		error: refs/tags/.lock: badRefName: invalid refname format
 		EOF
-		rm -r "$branch_dir_prefix/$refname" &&
-		test_cmp expect err || return 1
-	done
+		rm $tag_dir_prefix/.lock &&
+		test_cmp expect err &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/$refname: badRefName: invalid refname format
+			EOF
+			rm "$branch_dir_prefix/$refname" &&
+			test_cmp expect err || return 1
+		done &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			cp $tag_dir_prefix/default-tag "$tag_dir_prefix/$refname" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/tags/$refname: badRefName: invalid refname format
+			EOF
+			rm "$tag_dir_prefix/$refname" &&
+			test_cmp expect err || return 1
+		done &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			cp $tag_dir_prefix/multi_hierarchy/default-tag "$tag_dir_prefix/multi_hierarchy/$refname" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/tags/multi_hierarchy/$refname: badRefName: invalid refname format
+			EOF
+			rm "$tag_dir_prefix/multi_hierarchy/$refname" &&
+			test_cmp expect err || return 1
+		done &&
+
+		for refname in ".refname-starts-with-dot" "~refname-has-stride"
+		do
+			mkdir "$branch_dir_prefix/$refname" &&
+			cp $branch_dir_prefix/default-branch "$branch_dir_prefix/$refname/default-branch" &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/$refname/default-branch: badRefName: invalid refname format
+			EOF
+			rm -r "$branch_dir_prefix/$refname" &&
+			test_cmp expect err || return 1
+		done
+	)
 '
 
 test_expect_success 'ref name check should be adapted into fsck messages' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
-	cd repo &&
-	git commit --allow-empty -m initial &&
-	git checkout -b branch-1 &&
-
-	cp $branch_dir_prefix/branch-1 $branch_dir_prefix/.branch-1 &&
-	git -c fsck.badRefName=warn refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/.branch-1: badRefName: invalid refname format
-	EOF
-	rm $branch_dir_prefix/.branch-1 &&
-	test_cmp expect err &&
-
-	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
+	(
+		cd repo &&
+		git commit --allow-empty -m initial &&
+		git checkout -b branch-1 &&
+
+		cp $branch_dir_prefix/branch-1 $branch_dir_prefix/.branch-1 &&
+		git -c fsck.badRefName=warn refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/.branch-1: badRefName: invalid refname format
+		EOF
+		rm $branch_dir_prefix/.branch-1 &&
+		test_cmp expect err &&
+
+		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
+	)
 '
 
 test_expect_success 'ref name check should work for multiple worktrees' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-
-	cd repo &&
-	test_commit initial &&
-	git checkout -b branch-1 &&
-	test_commit second &&
-	git checkout -b branch-2 &&
-	test_commit third &&
-	git checkout -b branch-3 &&
-	git worktree add ./worktree-1 branch-1 &&
-	git worktree add ./worktree-2 branch-2 &&
-	worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
-	worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
-
-	(
-		cd worktree-1 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-3
-	) &&
 	(
-		cd worktree-2 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-3
-	) &&
-
-	cp $worktree1_refdir_prefix/branch-4 $worktree1_refdir_prefix/'\'' branch-5'\'' &&
-	cp $worktree2_refdir_prefix/branch-4 $worktree2_refdir_prefix/'\''~branch-6'\'' &&
-
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
-	error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
-	EOF
-	sort err >sorted_err &&
-	test_cmp expect sorted_err &&
-
-	for worktree in "worktree-1" "worktree-2"
-	do
+		cd repo &&
+		test_commit initial &&
+		git checkout -b branch-1 &&
+		test_commit second &&
+		git checkout -b branch-2 &&
+		test_commit third &&
+		git checkout -b branch-3 &&
+		git worktree add ./worktree-1 branch-1 &&
+		git worktree add ./worktree-2 branch-2 &&
+		worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
+		worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
+
 		(
-			cd $worktree &&
-			test_must_fail git refs verify 2>err &&
-			cat >expect <<-EOF &&
-			error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
-			error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
-			EOF
-			sort err >sorted_err &&
-			test_cmp expect sorted_err || return 1
-		)
-	done
+			cd worktree-1 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-3
+		) &&
+		(
+			cd worktree-2 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-3
+		) &&
+
+		cp $worktree1_refdir_prefix/branch-4 $worktree1_refdir_prefix/'\'' branch-5'\'' &&
+		cp $worktree2_refdir_prefix/branch-4 $worktree2_refdir_prefix/'\''~branch-6'\'' &&
+
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
+		error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
+		EOF
+		sort err >sorted_err &&
+		test_cmp expect sorted_err &&
+
+		for worktree in "worktree-1" "worktree-2"
+		do
+			(
+				cd $worktree &&
+				test_must_fail git refs verify 2>err &&
+				cat >expect <<-EOF &&
+				error: worktrees/worktree-1/refs/worktree/ branch-5: badRefName: invalid refname format
+				error: worktrees/worktree-2/refs/worktree/~branch-6: badRefName: invalid refname format
+				EOF
+				sort err >sorted_err &&
+				test_cmp expect sorted_err || return 1
+			)
+		done
+	)
 '
 
 test_expect_success 'regular ref content should be checked (individual)' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
 
-	git refs verify 2>err &&
-	test_must_be_empty err &&
+		git refs verify 2>err &&
+		test_must_be_empty err &&
 
-	for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$branch_dir_prefix/branch-bad &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/heads/branch-bad: badRefContent: $bad_content
-		EOF
-		rm $branch_dir_prefix/branch-bad &&
-		test_cmp expect err || return 1
-	done &&
+		for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$branch_dir_prefix/branch-bad &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/branch-bad: badRefContent: $bad_content
+			EOF
+			rm $branch_dir_prefix/branch-bad &&
+			test_cmp expect err || return 1
+		done &&
 
-	for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$branch_dir_prefix/a/b/branch-bad &&
-		test_must_fail git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		error: refs/heads/a/b/branch-bad: badRefContent: $bad_content
-		EOF
-		rm $branch_dir_prefix/a/b/branch-bad &&
-		test_cmp expect err || return 1
-	done &&
-
-	printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	rm $branch_dir_prefix/branch-no-newline &&
-	test_cmp expect err &&
-
-	for trailing_content in " garbage" "    more garbage"
-	do
-		printf "%s" "$(git rev-parse main)$trailing_content" >$branch_dir_prefix/branch-garbage &&
+		for bad_content in "$(git rev-parse main)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$branch_dir_prefix/a/b/branch-bad &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/a/b/branch-bad: badRefContent: $bad_content
+			EOF
+			rm $branch_dir_prefix/a/b/branch-bad &&
+			test_cmp expect err || return 1
+		done &&
+
+		printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
 		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\''$trailing_content'\''
+		warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
 		EOF
-		rm $branch_dir_prefix/branch-garbage &&
-		test_cmp expect err || return 1
-	done &&
+		rm $branch_dir_prefix/branch-no-newline &&
+		test_cmp expect err &&
 
-	printf "%s\n\n\n" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
+		for trailing_content in " garbage" "    more garbage"
+		do
+			printf "%s" "$(git rev-parse main)$trailing_content" >$branch_dir_prefix/branch-garbage &&
+			git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\''$trailing_content'\''
+			EOF
+			rm $branch_dir_prefix/branch-garbage &&
+			test_cmp expect err || return 1
+		done &&
 
+		printf "%s\n\n\n" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
 
-	'\''
-	EOF
-	rm $branch_dir_prefix/branch-garbage-special &&
-	test_cmp expect err &&
 
-	printf "%s\n\n\n  garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
+		'\''
+		EOF
+		rm $branch_dir_prefix/branch-garbage-special &&
+		test_cmp expect err &&
+
+		printf "%s\n\n\n  garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage-special &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-garbage-special: trailingRefContent: has trailing garbage: '\''
 
 
-	  garbage'\''
-	EOF
-	rm $branch_dir_prefix/branch-garbage-special &&
-	test_cmp expect err
+		  garbage'\''
+		EOF
+		rm $branch_dir_prefix/branch-garbage-special &&
+		test_cmp expect err
+	)
 '
 
 test_expect_success 'regular ref content should be checked (aggregate)' '
@@ -237,99 +244,103 @@ test_expect_success 'regular ref content should be checked (aggregate)' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	bad_content_1=$(git rev-parse main)x &&
-	bad_content_2=xfsazqfxcadas &&
-	bad_content_3=Xfsazqfxcadas &&
-	printf "%s" $bad_content_1 >$tag_dir_prefix/tag-bad-1 &&
-	printf "%s" $bad_content_2 >$tag_dir_prefix/tag-bad-2 &&
-	printf "%s" $bad_content_3 >$branch_dir_prefix/a/b/branch-bad &&
-	printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
-	printf "%s garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage &&
-
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: refs/heads/a/b/branch-bad: badRefContent: $bad_content_3
-	error: refs/tags/tag-bad-1: badRefContent: $bad_content_1
-	error: refs/tags/tag-bad-2: badRefContent: $bad_content_2
-	warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
-	warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	sort err >sorted_err &&
-	test_cmp expect sorted_err
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		bad_content_1=$(git rev-parse main)x &&
+		bad_content_2=xfsazqfxcadas &&
+		bad_content_3=Xfsazqfxcadas &&
+		printf "%s" $bad_content_1 >$tag_dir_prefix/tag-bad-1 &&
+		printf "%s" $bad_content_2 >$tag_dir_prefix/tag-bad-2 &&
+		printf "%s" $bad_content_3 >$branch_dir_prefix/a/b/branch-bad &&
+		printf "%s" "$(git rev-parse main)" >$branch_dir_prefix/branch-no-newline &&
+		printf "%s garbage" "$(git rev-parse main)" >$branch_dir_prefix/branch-garbage &&
+
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: refs/heads/a/b/branch-bad: badRefContent: $bad_content_3
+		error: refs/tags/tag-bad-1: badRefContent: $bad_content_1
+		error: refs/tags/tag-bad-2: badRefContent: $bad_content_2
+		warning: refs/heads/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
+		warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
+		EOF
+		sort err >sorted_err &&
+		test_cmp expect sorted_err
+	)
 '
 
 test_expect_success 'textual symref content should be checked (individual)' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		for good_referent in "refs/heads/branch" "HEAD"
+		do
+			printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
+			git refs verify 2>err &&
+			rm $branch_dir_prefix/branch-good &&
+			test_must_be_empty err || return 1
+		done &&
+
+		for bad_referent in "refs/heads/.branch" "refs/heads/~branch" "refs/heads/?branch"
+		do
+			printf "ref: %s\n" $bad_referent >$branch_dir_prefix/branch-bad &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: refs/heads/branch-bad: badReferentName: points to invalid refname '\''$bad_referent'\''
+			EOF
+			rm $branch_dir_prefix/branch-bad &&
+			test_cmp expect err || return 1
+		done &&
 
-	for good_referent in "refs/heads/branch" "HEAD"
-	do
-		printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
+		printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline &&
 		git refs verify 2>err &&
-		rm $branch_dir_prefix/branch-good &&
-		test_must_be_empty err || return 1
-	done &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
+		EOF
+		rm $branch_dir_prefix/branch-no-newline &&
+		test_cmp expect err &&
 
-	for bad_referent in "refs/heads/.branch" "refs/heads/~branch" "refs/heads/?branch"
-	do
-		printf "ref: %s\n" $bad_referent >$branch_dir_prefix/branch-bad &&
-		test_must_fail git refs verify 2>err &&
+		printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
+		EOF
+		rm $branch_dir_prefix/a/b/branch-trailing-1 &&
+		test_cmp expect err &&
+
+		printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: refs/heads/branch-bad: badReferentName: points to invalid refname '\''$bad_referent'\''
+		warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
 		EOF
-		rm $branch_dir_prefix/branch-bad &&
-		test_cmp expect err || return 1
-	done &&
-
-	printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	rm $branch_dir_prefix/branch-no-newline &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-trailing-1 &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-trailing-2 &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-trailing-3 &&
-	test_cmp expect err &&
-
-	printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
-	EOF
-	rm $branch_dir_prefix/a/b/branch-complicated &&
-	test_cmp expect err
+		rm $branch_dir_prefix/a/b/branch-trailing-2 &&
+		test_cmp expect err &&
+
+		printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
+		EOF
+		rm $branch_dir_prefix/a/b/branch-trailing-3 &&
+		test_cmp expect err &&
+
+		printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
+		EOF
+		rm $branch_dir_prefix/a/b/branch-complicated &&
+		test_cmp expect err
+	)
 '
 
 test_expect_success 'textual symref content should be checked (aggregate)' '
@@ -337,32 +348,34 @@ test_expect_success 'textual symref content should be checked (aggregate)' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	printf "ref: refs/heads/branch\n" >$branch_dir_prefix/branch-good &&
-	printf "ref: HEAD\n" >$branch_dir_prefix/branch-head &&
-	printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline-1 &&
-	printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
-	printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
-	printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
-	printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
-	printf "ref: refs/heads/.branch\n" >$branch_dir_prefix/branch-bad-1 &&
-
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	error: refs/heads/branch-bad-1: badReferentName: points to invalid refname '\''refs/heads/.branch'\''
-	warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
-	warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
-	warning: refs/heads/branch-no-newline-1: refMissingNewline: misses LF at the end
-	EOF
-	sort err >sorted_err &&
-	test_cmp expect sorted_err
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		printf "ref: refs/heads/branch\n" >$branch_dir_prefix/branch-good &&
+		printf "ref: HEAD\n" >$branch_dir_prefix/branch-head &&
+		printf "ref: refs/heads/branch" >$branch_dir_prefix/branch-no-newline-1 &&
+		printf "ref: refs/heads/branch     " >$branch_dir_prefix/a/b/branch-trailing-1 &&
+		printf "ref: refs/heads/branch\n\n" >$branch_dir_prefix/a/b/branch-trailing-2 &&
+		printf "ref: refs/heads/branch \n" >$branch_dir_prefix/a/b/branch-trailing-3 &&
+		printf "ref: refs/heads/branch \n  " >$branch_dir_prefix/a/b/branch-complicated &&
+		printf "ref: refs/heads/.branch\n" >$branch_dir_prefix/branch-bad-1 &&
+
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: refs/heads/branch-bad-1: badReferentName: points to invalid refname '\''refs/heads/.branch'\''
+		warning: refs/heads/a/b/branch-complicated: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-complicated: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/a/b/branch-trailing-1: refMissingNewline: misses LF at the end
+		warning: refs/heads/a/b/branch-trailing-1: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/a/b/branch-trailing-2: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/a/b/branch-trailing-3: trailingRefContent: has trailing whitespaces or newlines
+		warning: refs/heads/branch-no-newline-1: refMissingNewline: misses LF at the end
+		EOF
+		sort err >sorted_err &&
+		test_cmp expect sorted_err
+	)
 '
 
 test_expect_success 'the target of the textual symref should be checked' '
@@ -370,28 +383,30 @@ test_expect_success 'the target of the textual symref should be checked' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	for good_referent in "refs/heads/branch" "HEAD" "refs/tags/tag"
-	do
-		printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
-		git refs verify 2>err &&
-		rm $branch_dir_prefix/branch-good &&
-		test_must_be_empty err || return 1
-	done &&
-
-	for nonref_referent in "refs-back/heads/branch" "refs-back/tags/tag" "reflogs/refs/heads/branch"
-	do
-		printf "ref: %s\n" $nonref_referent >$branch_dir_prefix/branch-bad-1 &&
-		git refs verify 2>err &&
-		cat >expect <<-EOF &&
-		warning: refs/heads/branch-bad-1: symrefTargetIsNotARef: points to non-ref target '\''$nonref_referent'\''
-		EOF
-		rm $branch_dir_prefix/branch-bad-1 &&
-		test_cmp expect err || return 1
-	done
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		for good_referent in "refs/heads/branch" "HEAD" "refs/tags/tag"
+		do
+			printf "ref: %s\n" $good_referent >$branch_dir_prefix/branch-good &&
+			git refs verify 2>err &&
+			rm $branch_dir_prefix/branch-good &&
+			test_must_be_empty err || return 1
+		done &&
+
+		for nonref_referent in "refs-back/heads/branch" "refs-back/tags/tag" "reflogs/refs/heads/branch"
+		do
+			printf "ref: %s\n" $nonref_referent >$branch_dir_prefix/branch-bad-1 &&
+			git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: refs/heads/branch-bad-1: symrefTargetIsNotARef: points to non-ref target '\''$nonref_referent'\''
+			EOF
+			rm $branch_dir_prefix/branch-bad-1 &&
+			test_cmp expect err || return 1
+		done
+	)
 '
 
 test_expect_success SYMLINKS 'symlink symref content should be checked' '
@@ -399,201 +414,207 @@ test_expect_success SYMLINKS 'symlink symref content should be checked' '
 	git init repo &&
 	branch_dir_prefix=.git/refs/heads &&
 	tag_dir_prefix=.git/refs/tags &&
-	cd repo &&
-	test_commit default &&
-	mkdir -p "$branch_dir_prefix/a/b" &&
-
-	ln -sf ./main $branch_dir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $branch_dir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../logs/branch-escape $branch_dir_prefix/branch-symbolic &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
-	warning: refs/heads/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
-	EOF
-	rm $branch_dir_prefix/branch-symbolic &&
-	test_cmp expect err &&
-
-	ln -sf ./"branch   " $branch_dir_prefix/branch-symbolic-bad &&
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic-bad: symlinkRef: use deprecated symbolic link for symref
-	error: refs/heads/branch-symbolic-bad: badReferentName: points to invalid refname '\''refs/heads/branch   '\''
-	EOF
-	rm $branch_dir_prefix/branch-symbolic-bad &&
-	test_cmp expect err &&
-
-	ln -sf ./".tag" $tag_dir_prefix/tag-symbolic-1 &&
-	test_must_fail git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/tags/tag-symbolic-1: symlinkRef: use deprecated symbolic link for symref
-	error: refs/tags/tag-symbolic-1: badReferentName: points to invalid refname '\''refs/tags/.tag'\''
-	EOF
-	rm $tag_dir_prefix/tag-symbolic-1 &&
-	test_cmp expect err
+	(
+		cd repo &&
+		test_commit default &&
+		mkdir -p "$branch_dir_prefix/a/b" &&
+
+		ln -sf ./main $branch_dir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
+		EOF
+		rm $branch_dir_prefix/branch-symbolic-good &&
+		test_cmp expect err &&
+
+		ln -sf ../../logs/branch-escape $branch_dir_prefix/branch-symbolic &&
+		git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
+		warning: refs/heads/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
+		EOF
+		rm $branch_dir_prefix/branch-symbolic &&
+		test_cmp expect err &&
+
+		ln -sf ./"branch   " $branch_dir_prefix/branch-symbolic-bad &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/heads/branch-symbolic-bad: symlinkRef: use deprecated symbolic link for symref
+		error: refs/heads/branch-symbolic-bad: badReferentName: points to invalid refname '\''refs/heads/branch   '\''
+		EOF
+		rm $branch_dir_prefix/branch-symbolic-bad &&
+		test_cmp expect err &&
+
+		ln -sf ./".tag" $tag_dir_prefix/tag-symbolic-1 &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		warning: refs/tags/tag-symbolic-1: symlinkRef: use deprecated symbolic link for symref
+		error: refs/tags/tag-symbolic-1: badReferentName: points to invalid refname '\''refs/tags/.tag'\''
+		EOF
+		rm $tag_dir_prefix/tag-symbolic-1 &&
+		test_cmp expect err
+	)
 '
 
 test_expect_success SYMLINKS 'symlink symref content should be checked (worktree)' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-	cd repo &&
-	test_commit default &&
-	git branch branch-1 &&
-	git branch branch-2 &&
-	git branch branch-3 &&
-	git worktree add ./worktree-1 branch-2 &&
-	git worktree add ./worktree-2 branch-3 &&
-	main_worktree_refdir_prefix=.git/refs/heads &&
-	worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
-	worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
-
 	(
-		cd worktree-1 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
-	(
-		cd worktree-2 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
-
-	ln -sf ../../../../refs/heads/good-branch $worktree1_refdir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $worktree1_refdir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../../../worktrees/worktree-1/good-branch $worktree2_refdir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-2/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $worktree2_refdir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../worktrees/worktree-2/good-branch $main_worktree_refdir_prefix/branch-symbolic-good &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
-	EOF
-	rm $main_worktree_refdir_prefix/branch-symbolic-good &&
-	test_cmp expect err &&
-
-	ln -sf ../../../../logs/branch-escape $worktree1_refdir_prefix/branch-symbolic &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
-	warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
-	EOF
-	rm $worktree1_refdir_prefix/branch-symbolic &&
-	test_cmp expect err &&
-
-	for bad_referent_name in ".tag" "branch   "
-	do
-		ln -sf ./"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git branch branch-3 &&
+		git worktree add ./worktree-1 branch-2 &&
+		git worktree add ./worktree-2 branch-3 &&
+		main_worktree_refdir_prefix=.git/refs/heads &&
+		worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
+		worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
+
+		(
+			cd worktree-1 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+		(
+			cd worktree-2 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+
+		ln -sf ../../../../refs/heads/good-branch $worktree1_refdir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-1/refs/worktree/$bad_referent_name'\''
+		warning: worktrees/worktree-1/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
 		EOF
-		rm $worktree1_refdir_prefix/bad-symbolic &&
+		rm $worktree1_refdir_prefix/branch-symbolic-good &&
 		test_cmp expect err &&
 
-		ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		ln -sf ../../../../worktrees/worktree-1/good-branch $worktree2_refdir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+		warning: worktrees/worktree-2/refs/worktree/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
 		EOF
-		rm $worktree1_refdir_prefix/bad-symbolic &&
+		rm $worktree2_refdir_prefix/branch-symbolic-good &&
 		test_cmp expect err &&
 
-		ln -sf ./"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		ln -sf ../../worktrees/worktree-2/good-branch $main_worktree_refdir_prefix/branch-symbolic-good &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-2/refs/worktree/$bad_referent_name'\''
+		warning: refs/heads/branch-symbolic-good: symlinkRef: use deprecated symbolic link for symref
 		EOF
-		rm $worktree2_refdir_prefix/bad-symbolic &&
+		rm $main_worktree_refdir_prefix/branch-symbolic-good &&
 		test_cmp expect err &&
 
-		ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
-		test_must_fail git refs verify 2>err &&
+		ln -sf ../../../../logs/branch-escape $worktree1_refdir_prefix/branch-symbolic &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
-		error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+		warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symlinkRef: use deprecated symbolic link for symref
+		warning: worktrees/worktree-1/refs/worktree/branch-symbolic: symrefTargetIsNotARef: points to non-ref target '\''logs/branch-escape'\''
 		EOF
-		rm $worktree2_refdir_prefix/bad-symbolic &&
-		test_cmp expect err || return 1
-	done
+		rm $worktree1_refdir_prefix/branch-symbolic &&
+		test_cmp expect err &&
+
+		for bad_referent_name in ".tag" "branch   "
+		do
+			ln -sf ./"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-1/refs/worktree/$bad_referent_name'\''
+			EOF
+			rm $worktree1_refdir_prefix/bad-symbolic &&
+			test_cmp expect err &&
+
+			ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree1_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-1/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-1/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+			EOF
+			rm $worktree1_refdir_prefix/bad-symbolic &&
+			test_cmp expect err &&
+
+			ln -sf ./"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''worktrees/worktree-2/refs/worktree/$bad_referent_name'\''
+			EOF
+			rm $worktree2_refdir_prefix/bad-symbolic &&
+			test_cmp expect err &&
+
+			ln -sf ../../../../refs/heads/"$bad_referent_name" $worktree2_refdir_prefix/bad-symbolic &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			warning: worktrees/worktree-2/refs/worktree/bad-symbolic: symlinkRef: use deprecated symbolic link for symref
+			error: worktrees/worktree-2/refs/worktree/bad-symbolic: badReferentName: points to invalid refname '\''refs/heads/$bad_referent_name'\''
+			EOF
+			rm $worktree2_refdir_prefix/bad-symbolic &&
+			test_cmp expect err || return 1
+		done
+	)
 '
 
 test_expect_success 'ref content checks should work with worktrees' '
 	test_when_finished "rm -rf repo" &&
 	git init repo &&
-	cd repo &&
-	test_commit default &&
-	git branch branch-1 &&
-	git branch branch-2 &&
-	git branch branch-3 &&
-	git worktree add ./worktree-1 branch-2 &&
-	git worktree add ./worktree-2 branch-3 &&
-	worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
-	worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
-
 	(
-		cd worktree-1 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
-	(
-		cd worktree-2 &&
-		git update-ref refs/worktree/branch-4 refs/heads/branch-1
-	) &&
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git branch branch-3 &&
+		git worktree add ./worktree-1 branch-2 &&
+		git worktree add ./worktree-2 branch-3 &&
+		worktree1_refdir_prefix=.git/worktrees/worktree-1/refs/worktree &&
+		worktree2_refdir_prefix=.git/worktrees/worktree-2/refs/worktree &&
 
-	for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$worktree1_refdir_prefix/bad-branch-1 &&
-		test_must_fail git refs verify 2>err &&
+		(
+			cd worktree-1 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+		(
+			cd worktree-2 &&
+			git update-ref refs/worktree/branch-4 refs/heads/branch-1
+		) &&
+
+		for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$worktree1_refdir_prefix/bad-branch-1 &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: worktrees/worktree-1/refs/worktree/bad-branch-1: badRefContent: $bad_content
+			EOF
+			rm $worktree1_refdir_prefix/bad-branch-1 &&
+			test_cmp expect err || return 1
+		done &&
+
+		for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
+		do
+			printf "%s" $bad_content >$worktree2_refdir_prefix/bad-branch-2 &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: worktrees/worktree-2/refs/worktree/bad-branch-2: badRefContent: $bad_content
+			EOF
+			rm $worktree2_refdir_prefix/bad-branch-2 &&
+			test_cmp expect err || return 1
+		done &&
+
+		printf "%s" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-no-newline &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: worktrees/worktree-1/refs/worktree/bad-branch-1: badRefContent: $bad_content
+		warning: worktrees/worktree-1/refs/worktree/branch-no-newline: refMissingNewline: misses LF at the end
 		EOF
-		rm $worktree1_refdir_prefix/bad-branch-1 &&
-		test_cmp expect err || return 1
-	done &&
+		rm $worktree1_refdir_prefix/branch-no-newline &&
+		test_cmp expect err &&
 
-	for bad_content in "$(git rev-parse HEAD)x" "xfsazqfxcadas" "Xfsazqfxcadas"
-	do
-		printf "%s" $bad_content >$worktree2_refdir_prefix/bad-branch-2 &&
-		test_must_fail git refs verify 2>err &&
+		printf "%s garbage" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-garbage &&
+		git refs verify 2>err &&
 		cat >expect <<-EOF &&
-		error: worktrees/worktree-2/refs/worktree/bad-branch-2: badRefContent: $bad_content
+		warning: worktrees/worktree-1/refs/worktree/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
 		EOF
-		rm $worktree2_refdir_prefix/bad-branch-2 &&
-		test_cmp expect err || return 1
-	done &&
-
-	printf "%s" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-no-newline &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-no-newline: refMissingNewline: misses LF at the end
-	EOF
-	rm $worktree1_refdir_prefix/branch-no-newline &&
-	test_cmp expect err &&
-
-	printf "%s garbage" "$(git rev-parse HEAD)" >$worktree1_refdir_prefix/branch-garbage &&
-	git refs verify 2>err &&
-	cat >expect <<-EOF &&
-	warning: worktrees/worktree-1/refs/worktree/branch-garbage: trailingRefContent: has trailing garbage: '\'' garbage'\''
-	EOF
-	rm $worktree1_refdir_prefix/branch-garbage &&
-	test_cmp expect err
+		rm $worktree1_refdir_prefix/branch-garbage &&
+		test_cmp expect err
+	)
 '
 
 test_done

builtin/refs.c, worktree.c, worktree.h

diff --git a/builtin/refs.c b/builtin/refs.c
index a29f195834..55ff5dae11 100644
--- a/builtin/refs.c
+++ b/builtin/refs.c
@@ -88,7 +88,7 @@ static int cmd_refs_verify(int argc, const char **argv, const char *prefix,
 	git_config(git_fsck_config, &fsck_refs_options);
 	prepare_repo_settings(the_repository);
 
-	worktrees = get_worktrees();
+	worktrees = get_worktrees_without_reading_head();
 	for (size_t i = 0; worktrees[i]; i++)
 		ret |= refs_fsck(get_worktree_ref_store(worktrees[i]),
 				 &fsck_refs_options, worktrees[i]);
diff --git a/worktree.c b/worktree.c
index 248bbb39d4..89b7d86cef 100644
--- a/worktree.c
+++ b/worktree.c
@@ -175,6 +175,11 @@ struct worktree **get_worktrees(void)
 	return get_worktrees_internal(0);
 }
 
+struct worktree **get_worktrees_without_reading_head(void)
+{
+	return get_worktrees_internal(1);
+}
+
 const char *get_worktree_git_dir(const struct worktree *wt)
 {
 	if (!wt)
diff --git a/worktree.h b/worktree.h
index 38145df80f..1ba4a161a0 100644
--- a/worktree.h
+++ b/worktree.h
@@ -30,6 +30,12 @@ struct worktree {
  */
 struct worktree **get_worktrees(void);
 
+/*
+ * Like `get_worktrees`, but does not read HEAD. This is useful when checking
+ * the consistency, as reading HEAD may not be necessary.
+ */
+struct worktree **get_worktrees_without_reading_head(void);
+
 /*
  * Returns 1 if linked worktrees exist, 0 otherwise.
  */

refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index a7b6f74b6e..6401cecd5f 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -4,6 +4,7 @@
 #include "../git-compat-util.h"
 #include "../config.h"
 #include "../dir.h"
+#include "../fsck.h"
 #include "../gettext.h"
 #include "../hash.h"
 #include "../hex.h"
@@ -1748,15 +1749,45 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
-static int packed_fsck(struct ref_store *ref_store UNUSED,
-		       struct fsck_options *o UNUSED,
+static int packed_fsck(struct ref_store *ref_store,
+		       struct fsck_options *o,
 		       struct worktree *wt)
 {
+	struct packed_ref_store *refs = packed_downcast(ref_store,
+							REF_STORE_READ, "fsck");
+	int ret = 0;
+	int fd;
 
 	if (!is_main_worktree(wt))
-		return 0;
+		goto cleanup;
 
-	return 0;
+	if (o->verbose)
+		fprintf_ln(stderr, "Checking packed-refs file %s", refs->path);
+
+	fd = open_nofollow(refs->path, O_RDONLY);
+	if (fd < 0) {
+		/*
+		 * If the packed-refs file doesn't exist, there's nothing
+		 * to check.
+		 */
+		if (errno == ENOENT)
+			goto cleanup;
+
+		if (errno == ELOOP) {
+			struct fsck_ref_report report = { 0 };
+			report.path = "packed-refs";
+			ret = fsck_report_ref(o, &report,
+					      FSCK_MSG_BAD_REF_FILETYPE,
+					      "not a regular file");
+			goto cleanup;
+		}
+
+		ret = error_errno(_("unable to open %s"), refs->path);
+		goto cleanup;
+	}
+
+cleanup:
+	return ret;
 }
 
 struct ref_storage_be refs_be_packed = {
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index cf7a202d0d..42c8d4ca1e 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -617,4 +617,26 @@ test_expect_success 'ref content checks should work with worktrees' '
 	)
 '
 
+test_expect_success SYMLINKS 'the filetype of packed-refs should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git branch branch-3 &&
+		git pack-refs --all &&
+
+		mv .git/packed-refs .git/packed-refs-back &&
+		ln -sf packed-refs-bak .git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs: badRefFiletype: not a regular file
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err
+	)
+'
+
 test_done

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index b14bc44ca4..11906f90fd 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -16,6 +16,10 @@
 `badObjectSha1`::
 	(ERROR) An object has a bad sha1.
 
+`badPackedRefHeader`::
+	(ERROR) The "packed-refs" file contains an invalid
+	header.
+
 `badParentSha1`::
 	(ERROR) A commit object has a bad parent sha1.
 
@@ -176,6 +180,10 @@
 `nullSha1`::
 	(WARN) Tree contains entries pointing to a null sha1.
 
+`packedRefEntryNotTerminated`::
+	(ERROR) The "packed-refs" file contains an entry that is
+	not terminated by a newline.
+
 `refMissingNewline`::
 	(INFO) A loose ref that does not end with newline(LF). As
 	valid implementations of Git never created such a loose ref
diff --git a/fsck.h b/fsck.h
index a44c231a5f..67e3c97bc0 100644
--- a/fsck.h
+++ b/fsck.h
@@ -30,6 +30,7 @@ enum fsck_msg_type {
 	FUNC(BAD_EMAIL, ERROR) \
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
+	FUNC(BAD_PACKED_REF_HEADER, ERROR) \
 	FUNC(BAD_PARENT_SHA1, ERROR) \
 	FUNC(BAD_REF_CONTENT, ERROR) \
 	FUNC(BAD_REF_FILETYPE, ERROR) \
@@ -53,6 +54,7 @@ enum fsck_msg_type {
 	FUNC(MISSING_TYPE, ERROR) \
 	FUNC(MISSING_TYPE_ENTRY, ERROR) \
 	FUNC(MULTIPLE_AUTHORS, ERROR) \
+	FUNC(PACKED_REF_ENTRY_NOT_TERMINATED, ERROR) \
 	FUNC(TREE_NOT_SORTED, ERROR) \
 	FUNC(UNKNOWN_TYPE, ERROR) \
 	FUNC(ZERO_PADDED_DATE, ERROR) \
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 6401cecd5f..683cfe78dc 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1749,12 +1749,76 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
+static int packed_fsck_ref_next_line(struct fsck_options *o,
+				     struct strbuf *packed_entry, const char *start,
+				     const char *eof, const char **eol)
+{
+	int ret = 0;
+
+	*eol = memchr(start, '\n', eof - start);
+	if (!*eol) {
+		struct fsck_ref_report report = { 0 };
+
+		report.path = packed_entry->buf;
+		ret = fsck_report_ref(o, &report,
+				      FSCK_MSG_PACKED_REF_ENTRY_NOT_TERMINATED,
+				      "'%.*s' is not terminated with a newline",
+				      (int)(eof - start), start);
+
+		/*
+		 * There is no newline but we still want to parse it to the end of
+		 * the buffer.
+		 */
+		*eol = eof;
+	}
+
+	return ret;
+}
+
+static int packed_fsck_ref_header(struct fsck_options *o,
+				  const char *start, const char *eol)
+{
+	if (!starts_with(start, "# pack-refs with:")) {
+		struct fsck_ref_report report = { 0 };
+		report.path = "packed-refs.header";
+
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_HEADER,
+				       "'%.*s' does not start with '# pack-refs with:'",
+				       (int)(eol - start), start);
+	}
+
+	return 0;
+}
+
+static int packed_fsck_ref_content(struct fsck_options *o,
+				   const char *start, const char *eof)
+{
+	struct strbuf packed_entry = STRBUF_INIT;
+	unsigned long line_number = 1;
+	const char *eol;
+	int ret = 0;
+
+	strbuf_addf(&packed_entry, "packed-refs line %lu", line_number);
+	ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
+	if (*start == '#') {
+		ret |= packed_fsck_ref_header(o, start, eol);
+
+		start = eol + 1;
+		line_number++;
+	}
+
+	strbuf_release(&packed_entry);
+	return ret;
+}
+
 static int packed_fsck(struct ref_store *ref_store,
 		       struct fsck_options *o,
 		       struct worktree *wt)
 {
 	struct packed_ref_store *refs = packed_downcast(ref_store,
 							REF_STORE_READ, "fsck");
+	struct strbuf packed_ref_content = STRBUF_INIT;
 	int ret = 0;
 	int fd;
 
@@ -1786,7 +1850,16 @@ static int packed_fsck(struct ref_store *ref_store,
 		goto cleanup;
 	}
 
+	if (strbuf_read(&packed_ref_content, fd, 0) < 0) {
+		ret = error_errno(_("unable to read %s"), refs->path);
+		goto cleanup;
+	}
+
+	ret = packed_fsck_ref_content(o, packed_ref_content.buf,
+				      packed_ref_content.buf + packed_ref_content.len);
+
 cleanup:
+	strbuf_release(&packed_ref_content);
 	return ret;
 }
 
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 42c8d4ca1e..da321f16c6 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -639,4 +639,29 @@ test_expect_success SYMLINKS 'the filetype of packed-refs should be checked' '
 	)
 '
 
+test_expect_success 'packed-refs header should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+
+		git refs verify 2>err &&
+		test_must_be_empty err &&
+
+		for bad_header in "# pack-refs wit: peeled fully-peeled sorted " \
+				  "# pack-refs with traits: peeled fully-peeled sorted " \
+				  "# pack-refs with a: peeled fully-peeled"
+		do
+			printf "%s\n" "$bad_header" >.git/packed-refs &&
+			test_must_fail git refs verify 2>err &&
+			cat >expect <<-EOF &&
+			error: packed-refs.header: badPackedRefHeader: '\''$bad_header'\'' does not start with '\''# pack-refs with:'\''
+			EOF
+			rm .git/packed-refs &&
+			test_cmp expect err || return 1
+		done
+	)
+'
+
 test_done

diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 683cfe78dc..c8bb93bb18 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -494,6 +494,21 @@ static void verify_buffer_safe(struct snapshot *snapshot)
 				 last_line, eof - last_line);
 }
 
+/*
+ * When parsing the "packed-refs" file, we will parse it line by line.
+ * Because we know the start pointer of the refname and the next
+ * newline pointer, we could calculate the length of the refname by
+ * subtracting the two pointers. However, there is a corner case where
+ * the refname contains corrupted embedded NUL characters. And
+ * `check_refname_format()` will not catch this when the truncated
+ * refname is still a valid refname. To prevent this, we need to check
+ * whether the refname contains the NUL characters.
+ */
+static int refname_contains_nul(struct strbuf *refname)
+{
+	return !!memchr(refname->buf, '\0', refname->len);
+}
+
 #define SMALL_FILE_SIZE (32*1024)
 
 /*
@@ -895,6 +910,9 @@ static int next_record(struct packed_ref_iterator *iter)
 	strbuf_add(&iter->refname_buf, p, eol - p);
 	iter->base.refname = iter->refname_buf.buf;
 
+	if (refname_contains_nul(&iter->refname_buf))
+		die("packed refname contains embedded NULL: %s", iter->base.refname);
+
 	if (check_refname_format(iter->base.refname, REFNAME_ALLOW_ONELEVEL)) {
 		if (!refname_is_safe(iter->base.refname))
 			die("packed refname is dangerous: %s",

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index 11906f90fd..02a7bf0503 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -16,6 +16,9 @@
 `badObjectSha1`::
 	(ERROR) An object has a bad sha1.
 
+`badPackedRefEntry`::
+	(ERROR) The "packed-refs" file contains an invalid entry.
+
 `badPackedRefHeader`::
 	(ERROR) The "packed-refs" file contains an invalid
 	header.
diff --git a/fsck.h b/fsck.h
index 67e3c97bc0..14d70f6653 100644
--- a/fsck.h
+++ b/fsck.h
@@ -30,6 +30,7 @@ enum fsck_msg_type {
 	FUNC(BAD_EMAIL, ERROR) \
 	FUNC(BAD_NAME, ERROR) \
 	FUNC(BAD_OBJECT_SHA1, ERROR) \
+	FUNC(BAD_PACKED_REF_ENTRY, ERROR) \
 	FUNC(BAD_PACKED_REF_HEADER, ERROR) \
 	FUNC(BAD_PARENT_SHA1, ERROR) \
 	FUNC(BAD_REF_CONTENT, ERROR) \
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index c8bb93bb18..658f6bc7da 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1809,10 +1809,83 @@ static int packed_fsck_ref_header(struct fsck_options *o,
 	return 0;
 }
 
+static int packed_fsck_ref_peeled_line(struct fsck_options *o,
+				       struct ref_store *ref_store,
+				       struct strbuf *packed_entry,
+				       const char *start, const char *eol)
+{
+	struct fsck_ref_report report = { 0 };
+	struct object_id peeled;
+	const char *p;
+
+	report.path = packed_entry->buf;
+
+	/*
+	 * Skip the '^' and parse the peeled oid.
+	 */
+	start++;
+	if (parse_oid_hex_algop(start, &peeled, &p, ref_store->repo->hash_algo))
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "'%.*s' has invalid peeled oid",
+				       (int)(eol - start), start);
+
+	if (p != eol)
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "has trailing garbage after peeled oid '%.*s'",
+				       (int)(eol - p), p);
+
+	return 0;
+}
+
+static int packed_fsck_ref_main_line(struct fsck_options *o,
+				     struct ref_store *ref_store,
+				     struct strbuf *packed_entry,
+				     struct strbuf *refname,
+				     const char *start, const char *eol)
+{
+	struct fsck_ref_report report = { 0 };
+	struct object_id oid;
+	const char *p;
+
+	report.path = packed_entry->buf;
+
+	if (parse_oid_hex_algop(start, &oid, &p, ref_store->repo->hash_algo))
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "'%.*s' has invalid oid",
+				       (int)(eol - start), start);
+
+	if (p == eol || !isspace(*p))
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "has no space after oid '%s' but with '%.*s'",
+				       oid_to_hex(&oid), (int)(eol - p), p);
+
+	p++;
+	strbuf_reset(refname);
+	strbuf_add(refname, p, eol - p);
+	if (refname_contains_nul(refname))
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_PACKED_REF_ENTRY,
+				       "refname '%s' contains NULL binaries",
+				       refname->buf);
+
+	if (check_refname_format(refname->buf, 0))
+		return fsck_report_ref(o, &report,
+				       FSCK_MSG_BAD_REF_NAME,
+				       "has bad refname '%s'", refname->buf);
+
+	return 0;
+}
+
 static int packed_fsck_ref_content(struct fsck_options *o,
+				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
 {
 	struct strbuf packed_entry = STRBUF_INIT;
+	struct strbuf refname = STRBUF_INIT;
 	unsigned long line_number = 1;
 	const char *eol;
 	int ret = 0;
@@ -1826,6 +1899,26 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 		line_number++;
 	}
 
+	while (start < eof) {
+		strbuf_reset(&packed_entry);
+		strbuf_addf(&packed_entry, "packed-refs line %lu", line_number);
+		ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
+		ret |= packed_fsck_ref_main_line(o, ref_store, &packed_entry, &refname, start, eol);
+		start = eol + 1;
+		line_number++;
+		if (start < eof && *start == '^') {
+			strbuf_reset(&packed_entry);
+			strbuf_addf(&packed_entry, "packed-refs line %lu", line_number);
+			ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
+			ret |= packed_fsck_ref_peeled_line(o, ref_store, &packed_entry,
+							   start, eol);
+			start = eol + 1;
+			line_number++;
+		}
+	}
+
+	strbuf_release(&packed_entry);
+	strbuf_release(&refname);
 	strbuf_release(&packed_entry);
 	return ret;
 }
@@ -1873,7 +1966,7 @@ static int packed_fsck(struct ref_store *ref_store,
 		goto cleanup;
 	}
 
-	ret = packed_fsck_ref_content(o, packed_ref_content.buf,
+	ret = packed_fsck_ref_content(o, ref_store, packed_ref_content.buf,
 				      packed_ref_content.buf + packed_ref_content.len);
 
 cleanup:
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index da321f16c6..3ab6b5bba5 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -664,4 +664,46 @@ test_expect_success 'packed-refs header should be checked' '
 	)
 '
 
+test_expect_success 'packed-refs content should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git tag -a annotated-tag-1 -m tag-1 &&
+		git tag -a annotated-tag-2 -m tag-2 &&
+
+		branch_1_oid=$(git rev-parse branch-1) &&
+		branch_2_oid=$(git rev-parse branch-2) &&
+		tag_1_oid=$(git rev-parse annotated-tag-1) &&
+		tag_2_oid=$(git rev-parse annotated-tag-2) &&
+		tag_1_peeled_oid=$(git rev-parse annotated-tag-1^{}) &&
+		tag_2_peeled_oid=$(git rev-parse annotated-tag-2^{}) &&
+		short_oid=$(printf "%s" $tag_1_peeled_oid | cut -c 1-4) &&
+
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s\n" "$short_oid refs/heads/branch-1" >>.git/packed-refs &&
+		printf "%sx\n" "$branch_1_oid" >>.git/packed-refs &&
+		printf "%s   refs/heads/bad-branch\n" "$branch_2_oid" >>.git/packed-refs &&
+		printf "%s refs/heads/branch.\n" "$branch_2_oid" >>.git/packed-refs &&
+		printf "%s refs/tags/annotated-tag-3\n" "$tag_1_oid" >>.git/packed-refs &&
+		printf "^%s\n" "$short_oid" >>.git/packed-refs &&
+		printf "%s refs/tags/annotated-tag-4.\n" "$tag_2_oid" >>.git/packed-refs &&
+		printf "^%s garbage\n" "$tag_2_peeled_oid" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 2: badPackedRefEntry: '\''$short_oid refs/heads/branch-1'\'' has invalid oid
+		error: packed-refs line 3: badPackedRefEntry: has no space after oid '\''$branch_1_oid'\'' but with '\''x'\''
+		error: packed-refs line 4: badRefName: has bad refname '\''  refs/heads/bad-branch'\''
+		error: packed-refs line 5: badRefName: has bad refname '\''refs/heads/branch.'\''
+		error: packed-refs line 7: badPackedRefEntry: '\''$short_oid'\'' has invalid peeled oid
+		error: packed-refs line 8: badRefName: has bad refname '\''refs/tags/annotated-tag-4.'\''
+		error: packed-refs line 9: badPackedRefEntry: has trailing garbage after peeled oid '\'' garbage'\''
+		EOF
+		test_cmp expect err
+	)
+'
+
 test_done

Documentation/fsck-msgids.txt, fsck.h, refs/packed-backend.c, t/t0602-reffiles-fsck.sh

diff --git a/Documentation/fsck-msgids.txt b/Documentation/fsck-msgids.txt
index 02a7bf0503..9601fff228 100644
--- a/Documentation/fsck-msgids.txt
+++ b/Documentation/fsck-msgids.txt
@@ -187,6 +187,9 @@
 	(ERROR) The "packed-refs" file contains an entry that is
 	not terminated by a newline.
 
+`packedRefUnsorted`::
+	(ERROR) The "packed-refs" file is not sorted.
+
 `refMissingNewline`::
 	(INFO) A loose ref that does not end with newline(LF). As
 	valid implementations of Git never created such a loose ref
diff --git a/fsck.h b/fsck.h
index 14d70f6653..19f3cb2773 100644
--- a/fsck.h
+++ b/fsck.h
@@ -56,6 +56,7 @@ enum fsck_msg_type {
 	FUNC(MISSING_TYPE_ENTRY, ERROR) \
 	FUNC(MULTIPLE_AUTHORS, ERROR) \
 	FUNC(PACKED_REF_ENTRY_NOT_TERMINATED, ERROR) \
+	FUNC(PACKED_REF_UNSORTED, ERROR) \
 	FUNC(TREE_NOT_SORTED, ERROR) \
 	FUNC(UNKNOWN_TYPE, ERROR) \
 	FUNC(ZERO_PADDED_DATE, ERROR) \
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 658f6bc7da..0fbdc5c3fa 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -300,14 +300,9 @@ struct snapshot_record {
 	size_t len;
 };
 
-static int cmp_packed_ref_records(const void *v1, const void *v2,
-				  void *cb_data)
-{
-	const struct snapshot *snapshot = cb_data;
-	const struct snapshot_record *e1 = v1, *e2 = v2;
-	const char *r1 = e1->start + snapshot_hexsz(snapshot) + 1;
-	const char *r2 = e2->start + snapshot_hexsz(snapshot) + 1;
 
+static int cmp_packed_refname(const char *r1, const char *r2)
+{
 	while (1) {
 		if (*r1 == '\n')
 			return *r2 == '\n' ? 0 : -1;
@@ -322,6 +317,17 @@ static int cmp_packed_ref_records(const void *v1, const void *v2,
 	}
 }
 
+static int cmp_packed_ref_records(const void *v1, const void *v2,
+				  void *cb_data)
+{
+	const struct snapshot *snapshot = cb_data;
+	const struct snapshot_record *e1 = v1, *e2 = v2;
+	const char *r1 = e1->start + snapshot_hexsz(snapshot) + 1;
+	const char *r2 = e2->start + snapshot_hexsz(snapshot) + 1;
+
+	return cmp_packed_refname(r1, r2);
+}
+
 /*
  * Compare a snapshot record at `rec` to the specified NUL-terminated
  * refname.
@@ -1767,6 +1773,28 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
 	return empty_ref_iterator_begin();
 }
 
+struct fsck_packed_ref_entry {
+	unsigned long line_number;
+
+	struct snapshot_record record;
+};
+
+static struct fsck_packed_ref_entry *create_fsck_packed_ref_entry(unsigned long line_number,
+								  const char *start)
+{
+	struct fsck_packed_ref_entry *entry = xcalloc(1, sizeof(*entry));
+	entry->line_number = line_number;
+	entry->record.start = start;
+	return entry;
+}
+
+static void free_fsck_packed_ref_entries(struct fsck_packed_ref_entry **entries, size_t nr)
+{
+	for (size_t i = 0; i < nr; i++)
+		free(entries[i]);
+	free(entries);
+}
+
 static int packed_fsck_ref_next_line(struct fsck_options *o,
 				     struct strbuf *packed_entry, const char *start,
 				     const char *eof, const char **eol)
@@ -1794,19 +1822,33 @@ static int packed_fsck_ref_next_line(struct fsck_options *o,
 }
 
 static int packed_fsck_ref_header(struct fsck_options *o,
-				  const char *start, const char *eol)
+				  const char *start, const char *eol,
+				  unsigned int *sorted)
 {
-	if (!starts_with(start, "# pack-refs with:")) {
+	struct string_list traits = STRING_LIST_INIT_NODUP;
+	char *tmp_line;
+	int ret = 0;
+	char *p;
+
+	tmp_line = xmemdupz(start, eol - start);
+	if (!skip_prefix(tmp_line, "# pack-refs with:", (const char **)&p)) {
 		struct fsck_ref_report report = { 0 };
 		report.path = "packed-refs.header";
 
-		return fsck_report_ref(o, &report,
-				       FSCK_MSG_BAD_PACKED_REF_HEADER,
-				       "'%.*s' does not start with '# pack-refs with:'",
-				       (int)(eol - start), start);
+		ret = fsck_report_ref(o, &report,
+				      FSCK_MSG_BAD_PACKED_REF_HEADER,
+				      "'%.*s' does not start with '# pack-refs with:'",
+				      (int)(eol - start), start);
+		goto cleanup;
 	}
 
-	return 0;
+	string_list_split_in_place(&traits, p, " ", -1);
+	*sorted = unsorted_string_list_has_string(&traits, "sorted");
+
+cleanup:
+	free(tmp_line);
+	string_list_clear(&traits, 0);
+	return ret;
 }
 
 static int packed_fsck_ref_peeled_line(struct fsck_options *o,
@@ -1880,26 +1922,80 @@ static int packed_fsck_ref_main_line(struct fsck_options *o,
 	return 0;
 }
 
+static int packed_fsck_ref_sorted(struct fsck_options *o,
+				  struct ref_store *ref_store,
+				  struct fsck_packed_ref_entry **entries,
+				  size_t nr)
+{
+	size_t hexsz = ref_store->repo->hash_algo->hexsz;
+	struct strbuf packed_entry = STRBUF_INIT;
+	struct fsck_ref_report report = { 0 };
+	struct strbuf refname1 = STRBUF_INIT;
+	struct strbuf refname2 = STRBUF_INIT;
+	int ret = 0;
+
+	for (size_t i = 1; i < nr; i++) {
+		const char *r1 = entries[i - 1]->record.start + hexsz + 1;
+		const char *r2 = entries[i]->record.start + hexsz + 1;
+
+		if (cmp_packed_refname(r1, r2) >= 0) {
+			const char *err_fmt =
+				"refname '%s' is not less than next refname '%s'";
+			const char *eol;
+			eol = memchr(entries[i - 1]->record.start, '\n',
+				     entries[i - 1]->record.len);
+			strbuf_add(&refname1, r1, eol - r1);
+			eol = memchr(entries[i]->record.start, '\n',
+				     entries[i]->record.len);
+			strbuf_add(&refname2, r2, eol - r2);
+
+			strbuf_addf(&packed_entry, "packed-refs line %lu",
+				    entries[i - 1]->line_number);
+			report.path = packed_entry.buf;
+			ret = fsck_report_ref(o, &report,
+					      FSCK_MSG_PACKED_REF_UNSORTED,
+					      err_fmt, refname1.buf, refname2.buf);
+			goto cleanup;
+		}
+	}
+
+cleanup:
+	strbuf_release(&packed_entry);
+	strbuf_release(&refname1);
+	strbuf_release(&refname2);
+	return ret;
+}
+
 static int packed_fsck_ref_content(struct fsck_options *o,
 				   struct ref_store *ref_store,
 				   const char *start, const char *eof)
 {
 	struct strbuf packed_entry = STRBUF_INIT;
+	struct fsck_packed_ref_entry **entries;
 	struct strbuf refname = STRBUF_INIT;
 	unsigned long line_number = 1;
+	unsigned int sorted = 0;
+	size_t entry_alloc = 20;
+	size_t entry_nr = 0;
 	const char *eol;
 	int ret = 0;
 
 	strbuf_addf(&packed_entry, "packed-refs line %lu", line_number);
 	ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
 	if (*start == '#') {
-		ret |= packed_fsck_ref_header(o, start, eol);
+		ret |= packed_fsck_ref_header(o, start, eol, &sorted);
 
 		start = eol + 1;
 		line_number++;
 	}
 
+	ALLOC_ARRAY(entries, entry_alloc);
 	while (start < eof) {
+		struct fsck_packed_ref_entry *entry
+			= create_fsck_packed_ref_entry(line_number, start);
+
+		ALLOC_GROW(entries, entry_nr + 1, entry_alloc);
+		entries[entry_nr++] = entry;
 		strbuf_reset(&packed_entry);
 		strbuf_addf(&packed_entry, "packed-refs line %lu", line_number);
 		ret |= packed_fsck_ref_next_line(o, &packed_entry, start, eof, &eol);
@@ -1915,11 +2011,16 @@ static int packed_fsck_ref_content(struct fsck_options *o,
 			start = eol + 1;
 			line_number++;
 		}
+		entry->record.len = start - entry->record.start;
 	}
 
+	if (!ret && sorted)
+		ret |= packed_fsck_ref_sorted(o, ref_store, entries, entry_nr);
+
 	strbuf_release(&packed_entry);
 	strbuf_release(&refname);
 	strbuf_release(&packed_entry);
+	free_fsck_packed_ref_entries(entries, entry_nr);
 	return ret;
 }
 
diff --git a/t/t0602-reffiles-fsck.sh b/t/t0602-reffiles-fsck.sh
index 3ab6b5bba5..adcb5c1bda 100755
--- a/t/t0602-reffiles-fsck.sh
+++ b/t/t0602-reffiles-fsck.sh
@@ -706,4 +706,67 @@ test_expect_success 'packed-refs content should be checked' '
 	)
 '
 
+test_expect_success 'packed-ref with sorted trait should be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git tag -a annotated-tag-1 -m tag-1 &&
+		branch_1_oid=$(git rev-parse branch-1) &&
+		branch_2_oid=$(git rev-parse branch-2) &&
+		tag_1_oid=$(git rev-parse annotated-tag-1) &&
+		tag_1_peeled_oid=$(git rev-parse annotated-tag-1^{}) &&
+		refname1="refs/heads/main" &&
+		refname2="refs/heads/foo" &&
+		refname3="refs/tags/foo" &&
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s %s\n" "$branch_2_oid" "$refname1" >>.git/packed-refs &&
+		printf "%s %s\n" "$branch_1_oid" "$refname2" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 2: packedRefUnsorted: refname '\''$refname1'\'' is not less than next refname '\''$refname2'\''
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err &&
+
+		printf "# pack-refs with: peeled fully-peeled sorted \n"  >.git/packed-refs &&
+		printf "%s %s\n" "$tag_1_oid" "$refname3" >>.git/packed-refs &&
+		printf "^%s\n" "$tag_1_peeled_oid" >>.git/packed-refs &&
+		printf "%s %s\n" "$branch_2_oid" "$refname2" >>.git/packed-refs &&
+		test_must_fail git refs verify 2>err &&
+		cat >expect <<-EOF &&
+		error: packed-refs line 2: packedRefUnsorted: refname '\''$refname3'\'' is not less than next refname '\''$refname2'\''
+		EOF
+		rm .git/packed-refs &&
+		test_cmp expect err
+	)
+'
+
+test_expect_success 'packed-ref without sorted trait should not be checked' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		test_commit default &&
+		git branch branch-1 &&
+		git branch branch-2 &&
+		git tag -a annotated-tag-1 -m tag-1 &&
+		branch_1_oid=$(git rev-parse branch-1) &&
+		branch_2_oid=$(git rev-parse branch-2) &&
+		tag_1_oid=$(git rev-parse annotated-tag-1) &&
+		tag_1_peeled_oid=$(git rev-parse annotated-tag-1^{}) &&
+		refname1="refs/heads/main" &&
+		refname2="refs/heads/foo" &&
+		refname3="refs/tags/foo" &&
+		printf "# pack-refs with: peeled fully-peeled \n"  >.git/packed-refs &&
+		printf "%s %s\n" "$branch_2_oid" "$refname1" >>.git/packed-refs &&
+		printf "%s %s\n" "$branch_1_oid" "$refname2" >>.git/packed-refs &&
+		git refs verify 2>err &&
+		test_must_be_empty err
+	)
+'
+
 test_done

Documentation/git-fsck.txt, builtin/fsck.c

diff --git a/Documentation/git-fsck.txt b/Documentation/git-fsck.txt
index 5b82e4605c..9bd433028f 100644
--- a/Documentation/git-fsck.txt
+++ b/Documentation/git-fsck.txt
@@ -12,7 +12,7 @@ SYNOPSIS
 'git fsck' [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
 	 [--[no-]full] [--strict] [--verbose] [--lost-found]
 	 [--[no-]dangling] [--[no-]progress] [--connectivity-only]
-	 [--[no-]name-objects] [<object>...]
+	 [--[no-]name-objects] [--[no-]references] [<object>...]
 
 DESCRIPTION
 -----------
@@ -104,6 +104,10 @@ care about this output and want to speed it up further.
 	progress status even if the standard error stream is not
 	directed to a terminal.
 
+--[no-]references::
+	Control whether to check the references database consistency
+	via 'git refs verify'. See linkgit:git-refs[1] for details.
+
 CONFIGURATION
 -------------
 
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 7a4dcb0716..f4f395cfbd 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -50,6 +50,7 @@ static int verbose;
 static int show_progress = -1;
 static int show_dangling = 1;
 static int name_objects;
+static int check_references = 1;
 #define ERROR_OBJECT 01
 #define ERROR_REACHABLE 02
 #define ERROR_PACK 04
@@ -905,11 +906,37 @@ static int check_pack_rev_indexes(struct repository *r, int show_progress)
 	return res;
 }
 
+static void fsck_refs(struct repository *r)
+{
+	struct child_process refs_verify = CHILD_PROCESS_INIT;
+	struct progress *progress = NULL;
+
+	if (show_progress)
+		progress = start_progress(r, _("Checking ref database"), 1);
+
+	if (verbose)
+		fprintf_ln(stderr, _("Checking ref database"));
+
+	child_process_init(&refs_verify);
+	refs_verify.git_cmd = 1;
+	strvec_pushl(&refs_verify.args, "refs", "verify", NULL);
+	if (verbose)
+		strvec_push(&refs_verify.args, "--verbose");
+	if (check_strict)
+		strvec_push(&refs_verify.args, "--strict");
+
+	if (run_command(&refs_verify))
+		errors_found |= ERROR_REFS;
+
+	display_progress(progress, 1);
+	stop_progress(&progress);
+}
+
 static char const * const fsck_usage[] = {
 	N_("git fsck [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]\n"
 	   "         [--[no-]full] [--strict] [--verbose] [--lost-found]\n"
 	   "         [--[no-]dangling] [--[no-]progress] [--connectivity-only]\n"
-	   "         [--[no-]name-objects] [<object>...]"),
+	   "         [--[no-]name-objects] [--[no-]references] [<object>...]"),
 	NULL
 };
 
@@ -928,6 +955,7 @@ static struct option fsck_opts[] = {
 				N_("write dangling objects in .git/lost-found")),
 	OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
 	OPT_BOOL(0, "name-objects", &name_objects, N_("show verbose names for reachable objects")),
+	OPT_BOOL(0, "references", &check_references, N_("check reference database consistency")),
 	OPT_END(),
 };
 
@@ -970,6 +998,9 @@ int cmd_fsck(int argc,
 	git_config(git_fsck_config, &fsck_obj_options);
 	prepare_repo_settings(the_repository);
 
+	if (check_references)
+		fsck_refs(the_repository);
+
 	if (connectivity_only) {
 		for_each_loose_object(mark_loose_for_connectivity, NULL, 0);
 		for_each_packed_object(the_repository,