From 0448dca832d70983e2f192d770a0eaba5b47934e Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Tue, 27 Sep 2016 10:38:01 +0100
Subject: [PATCH] Fail hard & fast if linkifyjs version is wrong

Rather than carrying on an ending up with undefineds deep within the bowels of linkifyjs when we try to linkify a room alias.
---
 src/linkify-matrix.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/linkify-matrix.js b/src/linkify-matrix.js
index 8dceb3a527..3786c944a5 100644
--- a/src/linkify-matrix.js
+++ b/src/linkify-matrix.js
@@ -22,6 +22,9 @@ function matrixLinkify(linkify) {
     var MultiToken = MT.Base;
     var S_START = linkify.parser.start;
 
+    if (TT.UNDERSCORE === undefined) {
+        throw new Error("linkify-matrix requires linkifyjs 2.1.1: this version is too old.");
+    }
 
     var ROOMALIAS = function(value) {
         MultiToken.call(this, value);