1 files changed, 43 insertions, 12 deletions

diff --git a/builtin-describe.c b/builtin-describe.c
index 7a148a2c26..05e309f5ad 100644
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -19,6 +19,7 @@ static int all;	/* Default to annotated tags only */
 static int tags;	/* But allow any tags if --tags is specified */
 static int abbrev = DEFAULT_ABBREV;
 static int max_candidates = 10;
+const char *pattern = NULL;
 
 struct commit_name {
 	int prio; /* annotated tag = 2, tag = 1, head = 0 */
@@ -45,21 +46,38 @@ static void add_to_known_names(const char *path,
 
 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
-	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+	int might_be_tag = !prefixcmp(path, "refs/tags/");
+	struct commit *commit;
 	struct object *object;
-	int prio;
+	unsigned char peeled[20];
+	int is_tag, prio;
 
-	if (!commit)
+	if (!all && !might_be_tag)
 		return 0;
-	object = parse_object(sha1);
+
+	if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
+		commit = lookup_commit_reference_gently(peeled, 1);
+		if (!commit)
+			return 0;
+		is_tag = !!hashcmp(sha1, commit->object.sha1);
+	} else {
+		commit = lookup_commit_reference_gently(sha1, 1);
+		object = parse_object(sha1);
+		if (!commit || !object)
+			return 0;
+		is_tag = object->type == OBJ_TAG;
+	}
+
 	/* If --all, then any refs are used.
 	 * If --tags, then any tags are used.
 	 * Otherwise only annotated tags are used.
 	 */
-	if (!prefixcmp(path, "refs/tags/")) {
-		if (object->type == OBJ_TAG)
+	if (might_be_tag) {
+		if (is_tag) {
 			prio = 2;
-		else
+			if (pattern && fnmatch(pattern, path + 10, 0))
+				prio = 0;
+		} else
 			prio = 1;
 	}
 	else
@@ -156,6 +174,8 @@ static void describe(const char *arg, int last_one)
 		return;
 	}
 
+	if (!max_candidates)
+		die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
 	if (debug)
 		fprintf(stderr, "searching to describe %s\n", arg);
 
@@ -252,26 +272,37 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 		OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 		OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 		OPT__ABBREV(&abbrev),
+		OPT_SET_INT(0, "exact-match", &max_candidates,
+			    "only output exact matches", 0),
 		OPT_INTEGER(0, "candidates", &max_candidates,
-					"consider <n> most recent tags (default: 10)"),
+			    "consider <n> most recent tags (default: 10)"),
+		OPT_STRING(0, "match",       &pattern, "pattern",
+			   "only consider tags matching <pattern>"),
 		OPT_END(),
 	};
 
 	argc = parse_options(argc, argv, options, describe_usage, 0);
-	if (max_candidates < 1)
-		max_candidates = 1;
+	if (max_candidates < 0)
+		max_candidates = 0;
 	else if (max_candidates > MAX_TAGS)
 		max_candidates = MAX_TAGS;
 
 	save_commit_buffer = 0;
 
 	if (contains) {
-		const char **args = xmalloc((4 + argc) * sizeof(char*));
+		const char **args = xmalloc((6 + argc) * sizeof(char*));
 		int i = 0;
 		args[i++] = "name-rev";
 		args[i++] = "--name-only";
-		if (!all)
+		args[i++] = "--no-undefined";
+		if (!all) {
 			args[i++] = "--tags";
+			if (pattern) {
+				char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
+				sprintf(s, "--refs=refs/tags/%s", pattern);
+				args[i++] = s;
+			}
+		}
 		memcpy(args + i, argv, argc * sizeof(char*));
 		args[i + argc] = NULL;
 		return cmd_name_rev(i + argc, args, prefix);