[PATCH] RPM spec updates.

[git.git] / merge-base.c

diff --git a/merge-base.c b/merge-base.c
index dac5e4b..5919566 100644 (file)
--- 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;
 }