Merge branch 'jc/maint-refresh-index-is-optional-for-status' into maint

* jc/maint-refresh-index-is-optional-for-status:
  status: don't require the repository to be writable

Author: gitster

builtin-commit.c

@@ -278,11 +278,13 @@ static char *prepare_index(int argc, const char **argv, const char *prefix, int
 	 * We still need to refresh the index here.
 	 */
 	if (!pathspec || !*pathspec) {
-		fd = hold_locked_index(&index_lock, 1);
+		fd = hold_locked_index(&index_lock, !is_status);
 		refresh_cache(refresh_flags);
-		if (write_cache(fd, active_cache, active_nr) ||
-		    commit_locked_index(&index_lock))
-			die("unable to write new_index file");
+		if (0 <= fd) {
+			if (write_cache(fd, active_cache, active_nr) ||
+			    commit_locked_index(&index_lock))
+				die("unable to write new_index file");
+		}
 		commit_style = COMMIT_AS_IS;
 		return get_index_file();
 	}