entry.c: check if file exists after checkout

larsxschneider · gitster · commit 11179eb31178 · 2017-10-06T14:59:16.000+09:00
If we are checking out a file and somebody else racily deletes our file,
then we would write garbage to the cache entry. Fix that by checking
the result of the lstat() call on that file. Print an error to the user
if the file does not exist.

Reported-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Lars Schneider &lt;larsxschneider@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/entry.c b/entry.c
@@ -341,7 +341,9 @@ static int write_entry(struct cache_entry *ce,
 	if (state->refresh_cache) {
 		assert(state->istate);
 		if (!fstat_done)
-			lstat(ce->name, &st);
+			if (lstat(ce->name, &st) < 0)
+				return error_errno("unable to stat just-written file %s",
+						   ce->name);
 		fill_stat_cache_info(ce, &st);
 		ce->ce_flags |= CE_UPDATE_IN_BASE;
 		state->istate->cache_changed |= CE_ENTRY_CHANGED;
