refs: move submodule slash stripping code to get_submodule_ref_store

This is a better place that will benefit all submodule callers instead
of just resolve_gitlink_ref()

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pclouds

refs.c

@@ -1503,25 +1503,10 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
 int resolve_gitlink_ref(const char *submodule, const char *refname,
 			unsigned char *sha1)
 {
-	size_t len = strlen(submodule);
 	struct ref_store *refs;
 	int flags;
 
-	while (len && is_dir_sep(submodule[len - 1]))
-		len--;
-
-	if (!len)
-		return -1;
-
-	if (submodule[len]) {
-		/* We need to strip off one or more trailing slashes */
-		char *stripped = xmemdupz(submodule, len);
-
-		refs = get_submodule_ref_store(stripped);
-		free(stripped);
-	} else {
-		refs = get_submodule_ref_store(submodule);
-	}
+	refs = get_submodule_ref_store(submodule);
 
 	if (!refs)
 		return -1;
@@ -1636,6 +1621,16 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
 {
 	struct strbuf submodule_sb = STRBUF_INIT;
 	struct ref_store *refs;
+	char *to_free = NULL;
+	size_t len;
+
+	if (submodule) {
+		len = strlen(submodule);
+		while (len && is_dir_sep(submodule[len - 1]))
+			len--;
+		if (!len)
+			return NULL;
+	}
 
 	if (!submodule || !*submodule) {
 		/*
@@ -1645,6 +1640,10 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
 		return get_main_ref_store();
 	}
 
+	if (submodule[len])
+		/* We need to strip off one or more trailing slashes */
+		submodule = to_free = xmemdupz(submodule, len);
+
 	refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
 	if (refs)
 		goto done;
@@ -1664,6 +1663,8 @@ struct ref_store *get_submodule_ref_store(const char *submodule)
 
 done:
 	strbuf_release(&submodule_sb);
+	free(to_free);
+
 	return refs;
 }