cherry: remove redundant check for merge commit

While walking the revision list in get_patch_ids and cmd_cherry, we
check for each commit if there is more than one parent and ignore
the commit if that is the case. Instead, set rev_info.max_parents to
1 and let the revision traversal code handle it for us.
Signed-off-by: NMartin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin/log.c

@@ -718,6 +718,7 @@ static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids)
 
 	/* given a range a..b get all patch ids for b..a */
 	init_revisions(&check_rev, rev->prefix);
+	check_rev.max_parents = 1;
 	o1->flags ^= UNINTERESTING;
 	o2->flags ^= UNINTERESTING;
 	add_pending_object(&check_rev, o1, "o1");
@@ -726,10 +727,6 @@ static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids)
 		die(_("revision walk setup failed"));
 
 	while ((commit = get_revision(&check_rev)) != NULL) {
-		/* ignore merges */
-		if (commit->parents && commit->parents->next)
-			continue;
-
 		add_commit_patch_id(commit, ids);
 	}
 
@@ -1508,6 +1505,7 @@ int cmd_cherry(int argc, const char **argv, const char *prefix)
 	}
 
 	init_revisions(&revs, prefix);
+	revs.max_parents = 1;
 
 	if (add_pending_commit(head, &revs, 0))
 		die(_("Unknown commit %s"), head);
@@ -1530,10 +1528,6 @@ int cmd_cherry(int argc, const char **argv, const char *prefix)
 	if (prepare_revision_walk(&revs))
 		die(_("revision walk setup failed"));
 	while ((commit = get_revision(&revs)) != NULL) {
-		/* ignore merges */
-		if (commit->parents && commit->parents->next)
-			continue;
-
 		commit_list_insert(commit, &list);
 	}