Merge branch 'mh/find-uniq-abbrev'

The code to abbreviate an object name to its short unique prefix
has been optimized when no abbreviation was requested.

* mh/find-uniq-abbrev:
  sha1_name: avoid unnecessary sha1 lookup in find_unique_abbrev

Author: gitster

sha1_name.c

@@ -372,10 +372,10 @@ const char *find_unique_abbrev(const unsigned char *sha1, int len)
 	int status, exists;
 	static char hex[41];
 
-	exists = has_sha1_file(sha1);
 	memcpy(hex, sha1_to_hex(sha1), 40);
 	if (len == 40 || !len)
 		return hex;
+	exists = has_sha1_file(sha1);
 	while (len < 40) {
 		unsigned char sha1_ret[20];
 		status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);