+static void check_valid(unsigned char *sha1, const char *expect)
+{
+ void *buf;
+ char type[20];
+ unsigned long size;
+
+ buf = read_sha1_file(sha1, type, &size);
+ if (!buf || strcmp(type, expect))
+ die("%s is not a valid '%s' object", sha1_to_hex(sha1), expect);
+ free(buf);
+}
+