anchor.diff:  
   google.maps.Map.prototype.addTileInteractivity = function( tilejson, layerID, options ) {
     var map = this;
  +  // this is ugly but works, until Google maps changes and breaks it.
  +  // The main map div contains a div with z-index:0 that sets the cursor.
  +  // The third element in that div (with z-index: 3) is the lowest level
  +  // element that will capture any mouse events from the user.
  +  // The main goal here is to only respond to clicks on the map and only
  +  // on the map, and nothing that might be shown over the map, like
  +  // another infowindow or other Google Maps, or custom map, UI
  +  var googleMainMapDiv = $(map.div).find("div[style*='cursor'][style*='z-index: 0']");
  +  var googleMapInteractionsDiv = $(googleMainMapDiv).children()[2];
  +
     var interactionOn = false;
     var waxInteraction = wax.g.interaction( );
     var oldFeature = waxInteraction.screen_feature;
  
positive.code:         interactionOn = true;
          map.setOptions({ draggableCursor: 'pointer' });
          if (o.e.type == 'click') {
            // this is ugly but works, until Google maps changes and breaks it.
            // The main map div contains a single div. That div's first element
            // contains the main map stuff. The third element in that
            // div (with z-index: 3) is a div 100% wide and high representing the
            // map panel.
            // The main goal here is to only respond to clicks on the map and only
            // on the map, and nothing that might be shown over the map, like
            // another infowindow or other Google Maps, or custom map, UI
            var clickableDiv = $($($(map.div).children()[0]).children()[0]).children()[2];
            // if a native infoWindow was just opened, don't let another one open
            if( infoWindowOpenTime && new Date( ) - infoWindowOpenTime < 500 ) {
              return false;
  
negative.code:           // require the click to be on the map itself and not any other
            // element on top of the map, including Google Maps UI, custom
            // overlays, or observation infoWindows
            if(googleMapInteractionsDiv !== o.e.target) { return false; }
            // if a native infoWindow is still open, close it
            if( iNaturalist.Map.infoWindow ) { iNaturalist.Map.infoWindow.close( ); }
            // hide the legend if it is open so the infoWindow has room
  