git_reference_next_name must match git_reference_next

The git_reference_next API silently skips invalid references when
scanning the loose refs.  The git_reference_next_name API should
skip the same ones even though it isn't creating the reference
object.

This adds a test with a an invalid loose reference and makes sure
that both APIs skip the same entries and generate the same results.

1 files changed, 13 insertions, 3 deletions

diff --git a/src/refdb_fs.c b/src/refdb_fs.c
index b9e283ac5..2f1a5b26c 100644
--- a/src/refdb_fs.c
+++ b/src/refdb_fs.c
@@ -452,6 +452,9 @@ static int loose_lookup(
 	git_buf ref_file = GIT_BUF_INIT;
 	int error = 0;
 
+	if (out)
+		*out = NULL;
+
 	error = reference_read(&ref_file, NULL, backend->path, ref_name, NULL);
 
 	if (error < 0)
@@ -465,15 +468,17 @@ static int loose_lookup(
 			goto done;
 		}
 
-		*out = git_reference__alloc_symbolic(ref_name, target);
+		if (out)
+			*out = git_reference__alloc_symbolic(ref_name, target);
 	} else {
 		if ((error = loose_parse_oid(&oid, ref_name, &ref_file)) < 0)
 			goto done;
 
-		*out = git_reference__alloc(ref_name, &oid, NULL);
+		if (out)
+			*out = git_reference__alloc(ref_name, &oid, NULL);
 	}
 
-	if (*out == NULL)
+	if (out && *out == NULL)
 		error = -1;
 
 done:
@@ -679,6 +684,11 @@ static int refdb_fs_backend__iterator_next_name(
 		if (git_strmap_exists(packfile, path))
 			continue;
 
+		if (loose_lookup(NULL, backend, path) != 0) {
+			giterr_clear();
+			continue;
+		}
+
 		*out = path;
 		return 0;
 	}