From 17ffb3eca76ac5fdeec26cc3d6b5bc4c5da857b3 Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Mon, 12 Dec 2016 11:34:42 +0800
Subject: [PATCH] MDL-57125 comment: prevent js execution if there are no
 comments

---
 comment/comment.js | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/comment/comment.js b/comment/comment.js
index 91f87a4c910..9ae289598d1 100644
--- a/comment/comment.js
+++ b/comment/comment.js
@@ -410,19 +410,21 @@ M.core_comment = {
     },
     init_admin: function(Y) {
         var select_all = Y.one('#comment_select_all');
-        select_all.on('click', function(e) {
-            var comments = document.getElementsByName('comments');
-            var checked = false;
-            for (var i in comments) {
-                if (comments[i].checked) {
-                    checked=true;
+        if (select_all) {
+            select_all.on('click', function(e) {
+                var comments = document.getElementsByName('comments');
+                var checked = false;
+                for (var i in comments) {
+                    if (comments[i].checked) {
+                        checked=true;
+                    }
                 }
-            }
-            for (i in comments) {
-                comments[i].checked = !checked;
-            }
-            this.set('checked', !checked);
-        });
+                for (i in comments) {
+                    comments[i].checked = !checked;
+                }
+                this.set('checked', !checked);
+            });
+        }
 
         var comments_delete = Y.one('#comments_delete');
         if (comments_delete) {