Bug 208791 [Markers] NPE in ExtendedMarkersView
org.eclipse.swt.SWTException: Failed to execute runnable (java.lang.NullPointerException) at org.eclipse.swt.SWT.error(SWT.java:3706) at org.eclipse.swt.SWT.error(SWT.java:3624) [... snip ...] Caused by: java.lang.NullPointerException at org.eclipse.ui.internal.provisional.views.markers.ExtendedMarkersView$10.runInUIThread(ExtendedMarkersView.java:896) at org.eclipse.ui.progress.UIJob$1.run(UIJob.java:94) at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35) at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:130) ... 52 more This brought down testResourceMappings(), but you just need to check getCategories() can return null. PW
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/ExtendedMarkersView.java
return builder.getGenerator().getAllFilters();
	}
	/**
	 * Return all of the markers in the receiver.
	 * 
	 * @return IMarker[]
	 */
	IMarker[] getAllMarkers() {
		MarkerItem[] elements = builder.getElements();
		Collection allMarkers = new ArrayList();
		for (int i = 0; i < elements.length; i++) {
			addMarkers(elements[i], allMarkers);
		}
		IMarker[] markers = new IMarker[allMarkers.size()];
		allMarkers.toArray(markers);
		return markers;
	}
	/**
	 * Return all of the marker items in the receiver that are concrete.
	 * 
	 * @return MarkerItem[]
	 */
	MarkerItem[] getAllConcreteItems() {
		MarkerItem[] elements = builder.getElements();
		Collection allMarkers = new ArrayList();
		for (int i = 0; i < elements.length; i++) {
			addAllConcreteItems(elements[i], allMarkers);
		}
		MarkerItem[] markers = new MarkerItem[allMarkers.size()];
		allMarkers.toArray(markers);