Merge pull request oblador#166 from pkaminski/null-element

Guard against race condition when removing spies

Author: oblador

src/services/spy-api.js

@@ -28,7 +28,7 @@ angular.module('duScroll.spyAPI', ['duScroll.scrollContainerAPI'])
       for(i = 0; i < spies.length; i++) {
         spy = spies[i];
         pos = spy.getTargetPosition();
-        if (!pos) continue;
+        if (!pos || !spy.$element) continue;
 
         if((duScrollBottomSpy && bottomReached) || (pos.top + spy.offset - containerOffset < 20 && (duScrollGreedy || pos.top*-1 + containerOffset) < pos.height)) {
           //Find the one closest the viewport top or the page bottom if it's reached