dc12d7fd1157d99004e2a2fb2cf4090fbc47939a
tdreszer
  Wed Jun 11 16:27:02 2014 -0700
Backing out several of the previous 'tightening screws' changes.  In particular typeof(thing.var) !== 'undefined' if thing.var === null.  I thought I tested this eariler, but now it is breaking sortTable, as reported by QA.
diff --git src/hg/js/hgTracks.js src/hg/js/hgTracks.js
index 1109f22..708398c 100644
--- src/hg/js/hgTracks.js
+++ src/hg/js/hgTracks.js
@@ -1420,69 +1420,69 @@
             if (altColors) {
                 // lastMatch and lastBlue or not lastMatch and notLastBlue
                 lastBlue = (lastMatchesLast === lastBlue); 
                 if (lastBlue)    // Too  smart by 1/3rd
                     $( lastBtn ).addClass(    'btnBlue' );
                 else
                     $( lastBtn ).removeClass( 'btnBlue' );
             }
             count++;
         }
         //warn("Zipped "+count+" buttons "+countN+" are independent.");
     },
 
     dragHandleMouseOver: function ()
     {   // Highlights a single row when mouse over a dragHandle column (sideLabel and buttons)
-        if ( typeof(jQuery.tableDnD) === 'undefined' ) {
+        if ( ! jQuery.tableDnD ) {
             //var handle = $("td.dragHandle");
             //$(handle)
             //    .unbind('mouseenter')//, jQuery.tableDnD.mousemove);
             //    .unbind('mouseleave');//, jQuery.tableDnD.mouseup);
             return;
         }
-        if ( jQuery.tableDnD.dragObject === null ) {
+        if ( ! jQuery.tableDnD.dragObject ) {
             $( this ).parents("tr.trDraggable").addClass("trDrag");
         }
     },
 
     dragHandleMouseOut: function ()
     {   // Ends row highlighting by mouse over
         $( this ).parents("tr.trDraggable").removeClass("trDrag");
     },
 
     buttonMouseOver: function ()
     {   // Highlights a composite set of buttons, regarless of whether tracks are adjacent
-        if ( typeof(jQuery.tableDnD) === 'undefined' || jQuery.tableDnD.dragObject === null ) {
+        if ( ! jQuery.tableDnD || ! jQuery.tableDnD.dragObject ) {
             var classList = $( this ).attr("class").split(" ");
             var btns = $( "p." + classList[0] );
             $( btns ).removeClass('btnGrey');
             $( btns ).addClass('btnBlue');
-            if (typeof(jQuery.tableDnD) !== 'undefined') {
+            if (jQuery.tableDnD) {
                 var rows = dragReorder.getContiguousRowSet($(this).parents('tr.trDraggable')[0]);
                 if (rows)
                     $( rows ).addClass("trDrag");
             }
         }
     },
 
     buttonMouseOut: function ()
     {   // Ends composite highlighting by mouse over
         var classList = $( this ).attr("class").split(" ");
         var btns = $( "p." + classList[0] );
         $( btns ).removeClass('btnBlue');
         $( btns ).addClass('btnGrey');
-        if (typeof(jQuery.tableDnD) !== 'undefined') {
+        if (jQuery.tableDnD) {
             var rows = dragReorder.getContiguousRowSet($(this).parents('tr.trDraggable')[0]);
             if (rows)
             $( rows ).removeClass("trDrag");
         }
     },
 
     trMouseOver: function (e)
     {   // Trying to make sure there is always a imageV2.lastTrack so that we know where we are
         var id = '';
         var a = /tr_(.*)/.exec($(this).attr('id'));  // voodoo
         if (a && a[1]) {
             id = a[1];
         }
         if (id.length > 0) {
             if ( ! imageV2.lastTrack || imageV2.lastTrack.id !== id)
@@ -1900,31 +1900,31 @@
 
   ///////////////////////////////////////
  //// rightClick (aka context menu) ////
 ///////////////////////////////////////
 var rightClick = {
 
     menu: null,
     selectedMenuItem: null,   // currently choosen context menu item (via context menu).
     floatingMenuItem: null,
     currentMapItem:   null,
     supportZoomCodon: false,  // turns on experimental feature (currently only in larry's tree).
 
     makeMapItem: function (id)
     {   // Create a dummy mapItem on the fly
         // (for objects that don't have corresponding entry in the map).
-        if (id && id.length > 0 && typeof(hgTracks.trackDb) !== 'undefined') {
+        if (id && id.length > 0 && hgTracks.trackDb) {
             var title;
             var rec = hgTracks.trackDb[id];
             if (rec) {
                 title = rec.shortLabel;
             } else {
                 title = id;
             }
             return {id: id, title: "configure " + title};
         } else {
             return null;
         }
     },
 
     findMapItem: function (e)
     {   // Find mapItem for given event; returns item object or null if none found.