From a26ff53c762ac7daf9f54a264b5f6ef9b52e2a8c Mon Sep 17 00:00:00 2001
From: Simon Grim <scary@tasty.sexy>
Date: Fri, 25 Mar 2016 03:21:07 +0500
Subject: [PATCH] add check for input string emptiness in filterLang()

---
 js/mobile_abstract.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/js/mobile_abstract.js b/js/mobile_abstract.js
index cd7358c..8356330 100644
--- a/js/mobile_abstract.js
+++ b/js/mobile_abstract.js
@@ -543,7 +543,9 @@ function filterLang(string) {
         var langFilterReason = '';
         var langFilterList = $.Options.filterLangList.val;
 
-        if (langFilterList.length > 0) {
+        if (!string) {
+            langFilterReason = polyglot.t('this is undefined', {'this': 'string'});
+        } else if (langFilterList.length > 0) {
             var langFilterAccuracy = $.Options.filterLangAccuracy.val;
             langFilterPass = (langFilterMode === 'whitelist') ? false : true;
             langFilterReason = polyglot.t('this doesnt contain that', {'this': polyglot.t(langFilterMode), 'that': polyglot.t('language of this')});