sort numerically

public/src/client/topic/fork.js

@@ -101,8 +101,8 @@ define('forum/topic/fork', function() {
 				post.css('opacity', '1.0');
 			}
 
-			if(pids.length) {
-				pids.sort();
+			if (pids.length) {
+				pids.sort(function(a,b) { return a - b; });
 				forkModal.find('#fork-pids').html(pids.toString());
 			} else {
 				showNoPostsSelected();

src/topics/fork.js

@@ -28,7 +28,9 @@ module.exports = function(Topics) {
 			return callback(new Error('[[error:invalid-pid]]'));
 		}
 
-		pids.sort();
+		pids.sort(function(a, b) {
+			return a - b;
+		});
 		var mainPid = pids[0];
 
 		async.parallel({