refs/files: introduce function to perform normal ref checks

In a subsequent commit we'll introduce new generic checks for direct
refs. These checks will be independent of the actual backend.

Introduce a new function `refs_fsck_ref()` that will be used for this
purpose. At the current point in time it's still empty, but it will get
populated in a subsequent commit.

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

refs.c

@@ -320,6 +320,13 @@ int check_refname_format(const char *refname, int flags)
 	return check_or_sanitize_refname(refname, flags, NULL);
 }
 
+int refs_fsck_ref(struct ref_store *refs UNUSED, struct fsck_options *o UNUSED,
+		  struct fsck_ref_report *report UNUSED,
+		  const char *refname UNUSED, const struct object_id *oid UNUSED)
+{
+	return 0;
+}
+
 int refs_fsck_symref(struct ref_store *refs UNUSED, struct fsck_options *o,
 		     struct fsck_ref_report *report,
 		     const char *refname UNUSED, const char *target)

refs.h

@@ -655,6 +655,14 @@ int check_refname_format(const char *refname, int flags);
 
 struct fsck_ref_report;
 
+/*
+ * Perform generic checks for a specific symref target. This function is
+ * expected to be called by the ref backends for every symbolic ref.
+ */
+int refs_fsck_ref(struct ref_store *refs, struct fsck_options *o,
+		  struct fsck_ref_report *report,
+		  const char *refname, const struct object_id *oid);
+
 /*
  * Perform generic checks for a specific symref target. This function is
  * expected to be called by the ref backends for every symbolic ref.

refs/files-backend.c

@@ -3833,6 +3833,8 @@ static int files_fsck_refs_content(struct ref_store *ref_store,
 					      "has trailing garbage: '%s'", trailing);
 			goto cleanup;
 		}
+
+		ret = refs_fsck_ref(ref_store, o, &report, target_name, &oid);
 	} else {
 		ret = files_fsck_symref_target(ref_store, o, &report,
 					       target_name, &referent, 0);