+#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.
- */
- parse_commit(rev1);
- parse_commit(rev2);
+ struct commit *rev1, *rev2, *ret;
+ unsigned char rev1key[20], rev2key[20];
- common = common_parent(lookup_rev(rev1), lookup_rev(rev2));
- if (!common)
- die("no common parent found");
- printf("%s\n", sha1_to_hex(common->sha1));
+ 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;
}