Merge pull request #8131 from minrk/sort-help

handle undefined when sorting quick help

IPython/html/static/base/js/keyboard.js

@@ -244,13 +244,13 b' define(['
             }
         }
         help.sort(function (a, b) {
-            if (a.help_index > b.help_index){
-                return 1;
+            if (a.help_index === b.help_index) {
+                return 0;
             }
-            if (a.help_index < b.help_index){
-                return -1;
+            if (a.help_index === undefined || a.help_index > b.help_index){
+                return 1;
             }
-            return 0;
+            return -1;
         });
         return help;
     };