wt-status: implement opportunisitc index update correctly

The require_clean_work_tree() function calls hold_locked_index() with die_on_error=0 to signal that it is OK if it fails to obtain the lock, but unconditionally calls update_index_if_able(), which will try to write into fd=-1. Signed-off-by: Junio C Hamano <gitster@pobox.com>

Junio C Hamano committed Dec 7, 2016 at 11:11 UTC 89d38fb26664038a85eb5a0da8fa4d23228e450d
1 file changed +4 -3
wt-status.c
+4 -3
@@ -2258,11 +2258,12 @@ int has_uncommitted_changes(int ignore_submodules)
2258 int require_clean_work_tree(const char *action, const char *hint, int ignore_submodules, int gently)
2259 {
2260 struct lock_file *lock_file = xcalloc(1, sizeof(*lock_file));
2261 - int err = 0;
2261 + int err = 0, fd;
2262
2263 - hold_locked_index(lock_file, 0);
2263 + fd = hold_locked_index(lock_file, 0);
2264 refresh_cache(REFRESH_QUIET);
2265 - update_index_if_able(&the_index, lock_file);
2265 + if (0 <= fd)
2266 + update_index_if_able(&the_index, lock_file);
2267 rollback_lock_file(lock_file);
2268
2269 if (has_unstaged_changes(ignore_submodules)) {