af753bb4b4c976f3dc634e5a138efa81f5962620
tdreszer
  Tue Oct 11 14:04:39 2011 -0700
Obscure dragZoom bug traced back to missing map item id.  redmine 5627.
diff --git src/hg/js/hgTracks.js src/hg/js/hgTracks.js
index 196075f..6e2dec9 100644
--- src/hg/js/hgTracks.js
+++ src/hg/js/hgTracks.js
@@ -1649,31 +1649,32 @@
         findTracksNormalize();
         updateMetaDataHelpLinks(0);
     }
 });
 
 function rulerModeToggle (ele)
 {
     autoHideSetting = !ele.checked;
     var obj = imgAreaSelect.data('imgAreaSelect');
     obj.setOptions({autoHide : autoHideSetting});
 }
 
 function makeMapItem(id)
 {
     // Create a dummy mapItem on the fly (for objects that don't have corresponding entry in the map).
-    if(typeof(hgTracks.trackDb) != "undefined" && hgTracks.trackDb != null) {
+    if(id && id.length > 0
+    && typeof(hgTracks.trackDb) != "undefined" && hgTracks.trackDb != null) {
         var title;
         var rec = hgTracks.trackDb[id];
         if(rec) {
             title = rec.shortLabel;
         } else {
             title = id;
         }
         return {id: id, title: "configure " + title};
     } else {
         return null;
     }
 }
 
 function mapItemMouseOver()
 {