ed8dbd64ca36974846ce471161da56c58a8d224a
braney
  Thu Mar 8 08:54:54 2018 -0800
don't use Javascript sets because IE doesn't completely support them.

diff --git src/hg/js/hgCollection.js src/hg/js/hgCollection.js
index 102c7f6..a93e803 100644
--- src/hg/js/hgCollection.js
+++ src/hg/js/hgCollection.js
@@ -509,35 +509,35 @@
         // called after AJAX call
         isDirty = false;
         if (!responseJson) {
             return;
         }
 
         if (goTracks) {
             // we go straight to hgTracks after save
             $form = $('#redirectForm');
             $form.submit();
         }
     }
 
     function getUniqueName(root) {
         // make sure name is unique in track hub
-        if (!collectionNames.has(root)) {
-            collectionNames.add(root);
+        if (!collectionNames[root]) {
+            collectionNames[root] = 1;
             return root;
         } else {
             var counter = 1;
 
             for(; ; counter++) {
                 var name  = root + counter;
-                if (!collectionNames.has(name)) {
-                    collectionNames.add(name);
+                if (!collectionNames[name]) {
+                    collectionNames[name] = 1;
                     return name;
                 }
             }
         }
     }
 
     return {
         init: init
     };
 }());