entry.c: check if file exists after checkout

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 <peff@peff.net>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/entry.c b/entry.c
index f879758c73894fa2d3bec01d310feb63924ec8c1..ab79f1f69c892a47a9494f9ebf4f96a7084f6cea 100644 (file)
--- a/entry.c
+++ b/entry.c
@@ -341,7 +341,9 @@ finish:
        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;