Merge branch 'jk/shallow-update-fix' into maint

* jk/shallow-update-fix:
shallow: verify shallow file after taking lock
shallow: automatically clean up shallow tempfiles
shallow: use stat_validity to check for up-to-date file

diff --combined fetch-pack.c
index f061f1fe85ea20549f860c4bf37980941f480833,ae8550eb48ae1c96dff2fcd1e47333cee7bc79fd..90d47da8a902f24bb6a7ae63654a104626751b1e
--- 1/fetch-pack.c
--- 2/fetch-pack.c
+++ b/fetch-pack.c
@@@ -439,8 -439,7 +439,8 @@@ done
        }
        strbuf_release(&req_buf);
  
 -      consume_shallow_list(args, fd[0]);
 +      if (!got_ready || !no_done)
 +              consume_shallow_list(args, fd[0]);
        while (flushes || multi_ack) {
                int ack = get_ack(fd[0], result_sha1);
                if (ack) {
@@@ -948,17 -947,6 +948,6 @@@ static void update_shallow(struct fetch
        if (!si->shallow || !si->shallow->nr)
                return;
  
-       if (alternate_shallow_file) {
-               /*
-                * The temporary shallow file is only useful for
-                * index-pack and unpack-objects because it may
-                * contain more roots than we want. Delete it.
-                */
-               if (*alternate_shallow_file)
-                       unlink(alternate_shallow_file);
-               free((char *)alternate_shallow_file);
-       }
- 
        if (args->cloning) {
                /*
                 * remote is shallow, but this is a clone, there are