builtin rebase: fast-forward to onto if it is a proper descendant

diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index 08d91b1f0c0172fef93f1a87bf0843a85f57ca37..790ceaeed68fae3f8696d0d59fb97aa67f88dbce 100644 (file)
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -110,54 +110,12 @@ static int handle_is_ancestor(int argc, const char **argv)
                return 1;
 }
 
-struct rev_collect {
-       struct commit **commit;
-       int nr;
-       int alloc;
-       unsigned int initial : 1;
-};
-
-static void add_one_commit(struct object_id *oid, struct rev_collect *revs)
-{
-       struct commit *commit;
-
-       if (is_null_oid(oid))
-               return;
-
-       commit = lookup_commit(the_repository, oid);
-       if (!commit ||
-           (commit->object.flags & TMP_MARK) ||
-           parse_commit(commit))
-               return;
-
-       ALLOC_GROW(revs->commit, revs->nr + 1, revs->alloc);
-       revs->commit[revs->nr++] = commit;
-       commit->object.flags |= TMP_MARK;
-}
-
-static int collect_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
-                                 const char *ident, timestamp_t timestamp,
-                                 int tz, const char *message, void *cbdata)
-{
-       struct rev_collect *revs = cbdata;
-
-       if (revs->initial) {
-               revs->initial = 0;
-               add_one_commit(ooid, revs);
-       }
-       add_one_commit(noid, revs);
-       return 0;
-}
-
 static int handle_fork_point(int argc, const char **argv)
 {
        struct object_id oid;
        char *refname;
+       struct commit *derived, *fork_point;
        const char *commitname;
-       struct rev_collect revs;
-       struct commit *derived;
-       struct commit_list *bases;
-       int i, ret = 0;
 
        switch (dwim_ref(argv[0], strlen(argv[0]), &oid, &refname)) {
        case 0:
@@ -173,41 +131,14 @@ static int handle_fork_point(int argc, const char **argv)
                die("Not a valid object name: '%s'", commitname);
 
        derived = lookup_commit_reference(the_repository, &oid);
-       memset(&revs, 0, sizeof(revs));
-       revs.initial = 1;
-       for_each_reflog_ent(refname, collect_one_reflog_ent, &revs);
 
-       if (!revs.nr && !get_oid(refname, &oid))
-               add_one_commit(&oid, &revs);
+       fork_point = get_fork_point(refname, derived);
 
-       for (i = 0; i < revs.nr; i++)
-               revs.commit[i]->object.flags &= ~TMP_MARK;
-
-       bases = get_merge_bases_many_dirty(derived, revs.nr, revs.commit);
-
-       /*
-        * There should be one and only one merge base, when we found
-        * a common ancestor among reflog entries.
-        */
-       if (!bases || bases->next) {
-               ret = 1;
-               goto cleanup_return;
-       }
-
-       /* And the found one must be one of the reflog entries */
-       for (i = 0; i < revs.nr; i++)
-               if (&bases->item->object == &revs.commit[i]->object)
-                       break; /* found */
-       if (revs.nr <= i) {
-               ret = 1; /* not found */
-               goto cleanup_return;
-       }
-
-       printf("%s\n", oid_to_hex(&bases->item->object.oid));
+       if (!fork_point)
+               return 1;
 
-cleanup_return:
-       free_commit_list(bases);
-       return ret;
+       printf("%s\n", oid_to_hex(&fork_point->object.oid));
+       return 0;
 }
 
 int cmd_merge_base(int argc, const char **argv, const char *prefix)