git grep: be careful to use mutexes only when they are initialized

diff --git a/builtin/tag.c b/builtin/tag.c
index 9d89616863f4b9102706c726c51e36acddef8997..9b6fd95494fd80240f88d49224199b7e621717e4 100644 (file)
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -407,12 +407,12 @@ static int parse_msg_arg(const struct option *opt, const char *arg, int unset)
 static int strbuf_check_tag_ref(struct strbuf *sb, const char *name)
 {
        if (name[0] == '-')
-               return CHECK_REF_FORMAT_ERROR;
+               return -1;
 
        strbuf_reset(sb);
        strbuf_addf(sb, "refs/tags/%s", name);
 
-       return check_ref_format(sb->buf);
+       return check_refname_format(sb->buf, 0);
 }
 
 int cmd_tag(int argc, const char **argv, const char *prefix)