1 files changed, 67 insertions, 11 deletions

diff --git a/builtin-describe.c b/builtin-describe.c
index ad3b469f3..d65c7d286 100644
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -2,10 +2,11 @@
 #include "commit.h"
 #include "tag.h"
 #include "refs.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
 #include "builtin.h"
 
-#define SEEN (1u << 0)
-
 static const char describe_usage[] =
 "git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
 
@@ -16,7 +17,7 @@ static int abbrev = DEFAULT_ABBREV;
 
 static int names, allocs;
 static struct commit_name {
-	const struct commit *commit;
+	struct commit *commit;
 	int prio; /* annotated tag = 2, tag = 1, head = 0 */
 	char path[FLEX_ARRAY]; /* more */
 } **name_array = NULL;
@@ -35,7 +36,7 @@ static struct commit_name *match(struct commit *cmit)
 }
 
 static void add_to_known_names(const char *path,
-			       const struct commit *commit,
+			       struct commit *commit,
 			       int prio)
 {
 	int idx;
@@ -98,6 +99,12 @@ static int compare_names(const void *_a, const void *_b)
 	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
 }
 
+struct possible_tag {
+	struct possible_tag *next;
+	struct commit_name *name;
+	unsigned long depth;
+};
+
 static void describe(const char *arg, int last_one)
 {
 	unsigned char sha1[20];
@@ -105,6 +112,7 @@ static void describe(const char *arg, int last_one)
 	struct commit_list *list;
 	static int initialized = 0;
 	struct commit_name *n;
+	struct possible_tag *all_matches, *min_match, *cur_match;
 
 	if (get_sha1(arg, sha1))
 		die("Not a valid object name %s", arg);
@@ -125,19 +133,67 @@ static void describe(const char *arg, int last_one)
 	}
 
 	list = NULL;
+	all_matches = NULL;
+	cur_match = NULL;
 	commit_list_insert(cmit, &list);
 	while (list) {
-		struct commit *c = pop_most_recent_commit(&list, SEEN);
+		struct commit *c = pop_commit(&list);
 		n = match(c);
 		if (n) {
-			printf("%s-g%s\n", n->path,
-			       find_unique_abbrev(cmit->object.sha1, abbrev));
-			if (!last_one)
-				clear_commit_marks(cmit, SEEN);
-			return;
+			struct possible_tag *p = xmalloc(sizeof(*p));
+			p->name = n;
+			p->next = NULL;
+			if (cur_match)
+				cur_match->next = p;
+			else
+				all_matches = p;
+			cur_match = p;
+		} else {
+			struct commit_list *parents = c->parents;
+			while (parents) {
+				struct commit *p = parents->item;
+				parse_commit(p);
+				if (!(p->object.flags & SEEN)) {
+					p->object.flags |= SEEN;
+					insert_by_date(p, &list);
+				}
+				parents = parents->next;
+			}
+		}
+	}
+
+	if (!all_matches)
+		die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
+
+	min_match = NULL;
+	for (cur_match = all_matches; cur_match; cur_match = cur_match->next) {
+		struct rev_info revs;
+		struct commit *tagged = cur_match->name->commit;
+
+		clear_commit_marks(cmit, -1);
+		init_revisions(&revs, NULL);
+		tagged->object.flags |= UNINTERESTING;
+		add_pending_object(&revs, &tagged->object, NULL);
+		add_pending_object(&revs, &cmit->object, NULL);
+
+		prepare_revision_walk(&revs);
+		cur_match->depth = 0;
+		while ((!min_match || cur_match->depth < min_match->depth)
+			&& get_revision(&revs))
+			cur_match->depth++;
+		if (!min_match || cur_match->depth < min_match->depth)
+			min_match = cur_match;
+	}
+	printf("%s-g%s\n", min_match->name->path,
+		   find_unique_abbrev(cmit->object.sha1, abbrev));
+
+	if (!last_one) {
+		for (cur_match = all_matches; cur_match; cur_match = min_match) {
+			min_match = cur_match->next;
+			free(cur_match);
 		}
+		clear_commit_marks(cmit, SEEN);
 	}
-	die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 }
 
 int cmd_describe(int argc, const char **argv, const char *prefix)