Merge branch 'jk/has-sha1-file-retry-packed'

When an object is not found after checking the packfiles and then
loose object directory, read_sha1_file() re-checks the packfiles to
prevent racing with a concurrent repacker; teach the same logic to
has_sha1_file().

* jk/has-sha1-file-retry-packed:
  has_sha1_file: re-check pack directory before giving up

sha1_file.c

@@ -2995,7 +2995,10 @@ int has_sha1_file(const unsigned char *sha1)
 
 	if (find_pack_entry(sha1, &e))
 		return 1;
-	return has_loose_object(sha1);
+	if (has_loose_object(sha1))
+		return 1;
+	reprepare_packed_git();
+	return find_pack_entry(sha1, &e);
 }
 
 static void check_tree(const void *buf, size_t size)