From add8ef3c59766ef4ff22d4a15d1ae812ea467b84 Mon Sep 17 00:00:00 2001
From: Matthew Hodgson <matthew@matrix.org>
Date: Fri, 22 Jan 2016 19:59:41 +0000
Subject: [PATCH] trap for ss.cssRules mysteriously returning null

---
 src/Tinter.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Tinter.js b/src/Tinter.js
index 3612be5b10..1e1d534bd5 100644
--- a/src/Tinter.js
+++ b/src/Tinter.js
@@ -76,6 +76,9 @@ var cached = false;
 function calcCssFixups() {
     for (var i = 0; i < document.styleSheets.length; i++) {
         var ss = document.styleSheets[i];
+        // Chromium apparently sometimes returns null here; unsure why.
+        // see $14534907369972FRXBx:matrix.org in HQ
+        if (!ss.cssRules) continue;
         for (var j = 0; j < ss.cssRules.length; j++) {
             var rule = ss.cssRules[j];
             if (!rule.style) continue;