cherry-pick: Suggest a better method to retain authorship

diff --git a/builtin-diff-index.c b/builtin-diff-index.c
index 95a3db156bda2d1e8d2ad7bdf72a9f9a821c6f51..083599d5c4c174cfab7c148428630534e4cd8174 100644 (file)
--- a/builtin-diff-index.c
+++ b/builtin-diff-index.c
@@ -38,5 +38,9 @@ int cmd_diff_index(int argc, const char **argv, const char *prefix)
        if (rev.pending.nr != 1 ||
            rev.max_count != -1 || rev.min_age != -1 || rev.max_age != -1)
                usage(diff_cache_usage);
+       if (read_cache() < 0) {
+               perror("read_cache");
+               return -1;
+       }
        return run_diff_index(&rev, cached);
 }