X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;ds=sidebyside;f=merge-base.c;h=591956666d06603d145ac9a5d2102185289e4c2c;hb=24db845c40b09c55eb810c01e7fda2f4505d35ba;hp=dac5e4b5e0da239dccc0ee1d43ffc6fb35e1a817;hpb=7d60ad7cc948b1b9e1066a3e740c91651bdc7e8d;p=git.git

diff --git a/merge-base.c b/merge-base.c
index dac5e4b5..59195666 100644
--- a/merge-base.c
+++ b/merge-base.c
@@ -1,54 +1,70 @@
+#include <stdlib.h>
 #include "cache.h"
-#include "revision.h"
+#include "commit.h"
 
-/*
- * This is stupid. We could have much better heurstics, I bet.
- */
-static int better(struct revision *new, struct revision *old)
+static struct commit *common_ancestor(struct commit *rev1, struct commit *rev2)
 {
-	return new->date > old->date;
-}
+	struct commit_list *list = NULL;
+	struct commit_list *result = NULL;
 
-static struct revision *common_parent(struct revision *rev1, struct revision *rev2)
-{
-	int i;
-	struct revision *best = NULL;
-
-	mark_reachable(rev1, 1);
-	mark_reachable(rev2, 2);
-	for (i = 0; i < nr_revs ;i++) {
-		struct revision *rev = revs[i];
-		if ((rev->flags & 3) != 3)
-			continue;
-		if (!best) {
-			best = rev;
+	if (rev1 == rev2)
+		return rev1;
+
+	parse_commit(rev1);
+	parse_commit(rev2);
+
+	rev1->object.flags |= 1;
+	rev2->object.flags |= 2;
+	insert_by_date(rev1, &list);
+	insert_by_date(rev2, &list);
+
+	while (list) {
+		struct commit *commit = list->item;
+		struct commit_list *tmp = list, *parents;
+		int flags = commit->object.flags & 3;
+
+		list = list->next;
+		free(tmp);
+		switch (flags) {
+		case 3:
+			insert_by_date(commit, &result);
 			continue;
+		case 0:
+			die("git-merge-base: commit without either parent?");
+		}
+		parents = commit->parents;
+		while (parents) {
+			struct commit *p = parents->item;
+			parents = parents->next;
+			if ((p->object.flags & flags) == flags)
+				continue;
+			parse_commit(p);
+			p->object.flags |= flags;
+			insert_by_date(p, &list);
 		}
-		if (better(rev, best))
-			best = rev;
 	}
-	return best;
+	if (!result)
+		return NULL;
+	return result->item;
 }
 
 int main(int argc, char **argv)
 {
-	unsigned char rev1[20], rev2[20];
-	struct revision *common;
-
-	if (argc != 3 || get_sha1_hex(argv[1], rev1) || get_sha1_hex(argv[2], rev2))
-		usage("merge-base <commit1> <commit2>");
-
-	/*
-	 * We will eventually want to include a revision cache file
-	 * that "rev-tree.c" has generated, since this is going to
-	 * otherwise be quite expensive for big trees..
-	 *
-	 * That's some time off, though, and in the meantime we know
-	 * that we have a solution to the eventual expense.
-	 */
-	common = common_parent(parse_commit(rev1), parse_commit(rev2));
-	if (!common)
-		die("no common parent found");
-	printf("%s\n", sha1_to_hex(common->sha1));
+	struct commit *rev1, *rev2, *ret;
+	unsigned char rev1key[20], rev2key[20];
+
+	if (argc != 3 ||
+	    get_sha1(argv[1], rev1key) ||
+	    get_sha1(argv[2], rev2key)) {
+		usage("git-merge-base <commit-id> <commit-id>");
+	}
+	rev1 = lookup_commit_reference(rev1key);
+	rev2 = lookup_commit_reference(rev2key);
+	if (!rev1 || !rev2)
+		return 1;
+	ret = common_ancestor(rev1, rev2);
+	if (!ret)
+		return 1;
+	printf("%s\n", sha1_to_hex(ret->object.sha1));
 	return 0;
 }