0001-git-describe-Die-early-if-there-are-no-possible-desc.patch

From 2776a399ff5d7e16bd421c4bd06feed3b67b7fdf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Steinbrink?= <B.Steinbrink@gmx.de>
Date: Wed, 5 Aug 2009 15:51:01 +0200
Subject: [PATCH] git-describe: Die early if there are no possible descriptions

If we found no refs that may be used for git-describe with the current
options, then die early instead of pointlessly walking the whole history.
---
 builtin-describe.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/builtin-describe.c b/builtin-describe.c
index 7a66298..cf802d1 100644
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -20,6 +20,7 @@ static int tags;	/* Allow lightweight tags */
 static int longformat;
 static int abbrev = DEFAULT_ABBREV;
 static int max_candidates = 10;
+static int found_names = 0;
 static const char *pattern;
 static int always;
 
@@ -39,6 +40,8 @@ static void add_to_known_names(const char *path,
 			       const unsigned char *sha1)
 {
 	struct commit_name *e = commit->util;
+	if (!e)
+		found_names++;
 	if (!e || e->prio < prio) {
 		size_t len = strlen(path)+1;
 		free(e);
@@ -195,6 +198,9 @@ static void describe(const char *arg, int last_one)
 		for_each_ref(get_name, NULL);
 	}
 
+	if (!found_names)
+		die("cannot describe '%s'", sha1_to_hex(sha1));
+
 	n = cmit->util;
 	if (n) {
 		/*
-- 
1.6.4.19.g42af.dirty