Bug 123319 [Markers] ClassCastException during marker update
3.2 20050116 It is possible to get the following ClassCastException during marker updates. This is because the refreshes are not IMarkers and should not be processed. !ENTRY org.eclipse.core.jobs 4 2 2006-01-10 16:00:48.468 !MESSAGE An internal error occurred during: "Process resource updates". !STACK 0 java.lang.ClassCastException at org.eclipse.ui.views.markers.internal.MarkerView$MarkerProcessJob.getExistingMarkers(MarkerView.java:206) at org.eclipse.ui.views.markers.internal.MarkerView$MarkerProcessJob.run(MarkerView.java:169) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:58)
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MarkerView.java
*/
		public boolean shouldRun() {
			
			return clipboard != null && buildDone;
		}
		/**
		 * Get the collection of Markers to remove.
		 * 
		 * @param existingMarkers
		 * @return Collection of ConcreteMarker
		 */
		private Collection getExistingMarkers(Collection existingMarkers) {
			if (existingMarkers.isEmpty())
				return Util.EMPTY_COLLECTION;
			Collection toRemove = new ArrayList();
			MarkerList currentList = getCurrentMarkers();
			Iterator removes = existingMarkers.iterator();
			while (removes.hasNext()) {
				Object next = currentList.getMarker((IMarker) removes.next());
				if (next != null)
					toRemove.add(next);
			}
			return toRemove;
		}
		/**
		 * Get the ConcreteMarkers being added after filtering.
		 * 
		 * @param addedMarkers
		 *            Collection of IMarker
		 * @return Collection of ConcreteMarker