Function get_fork_point

commit.c:1094–1149

}

struct commit *get_fork_point(const char *refname, struct commit *commit)
{
	struct object_id oid;
	struct rev_collect revs;
	struct commit_list *bases = NULL;
	size_t i;
	struct commit *ret = NULL;
	char *full_refname;

	switch (repo_dwim_ref(the_repository, refname, strlen(refname), &oid,
			      &full_refname, 0)) {
	case 0:
		die("No such ref: '%s'", refname);
	case 1:
		break; /* good */
	default:
		die("Ambiguous refname: '%s'", refname);
	}

	commit_stack_init(&revs.stack);
	revs.initial = 1;
	refs_for_each_reflog_ent(get_main_ref_store(the_repository),
				 full_refname, collect_one_reflog_ent, &revs);

	if (!revs.stack.nr)
		add_one_commit(&oid, &revs);

	for (i = 0; i < revs.stack.nr; i++)
		revs.stack.items[i]->object.flags &= ~TMP_MARK;

	if (repo_get_merge_bases_many(the_repository, commit, revs.stack.nr,
				      revs.stack.items, &bases) < 0)
		exit(128);

	/*
	 * There should be one and only one merge base, when we found
	 * a common ancestor among reflog entries.
	 */
	if (!bases || bases->next)
		goto cleanup_return;

	/* And the found one must be one of the reflog entries */
	for (i = 0; i < revs.stack.nr; i++)
		if (&bases->item->object == &revs.stack.items[i]->object)
			break; /* found */
	if (revs.stack.nr <= i)
		goto cleanup_return;

	ret = bases->item;

cleanup_return:
	commit_stack_clear(&revs.stack);
	commit_list_free(bases);
	free(full_refname);
	return ret;
}

/*