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
viewer = new MarkersTreeViewer(new Tree(parent, SWT.H_SCROLL
				| SWT.V_SCROLL | SWT.MULTI | SWT.FULL_SELECTION));
		viewer.getTree().setLinesVisible(true);
		viewer.setUseHashlookup(true);
		createColumns(new TreeColumn[0]);
		viewer.setContentProvider(getContentProvider());
		viewer.getTree().setItemCount(builder.getElements().length);
		viewer.setInput(builder);
		if (memento != null) {
			Scrollable scrollable = (Scrollable) viewer.getControl();
			ScrollBar bar = scrollable.getVerticalBar();
			if (bar != null) {
				Integer position = memento.getInteger(TAG_VERTICAL_POSITION);
				if (position != null)
					bar.setSelection(position.intValue());
			}
			bar = scrollable.getHorizontalBar();
			if (bar != null) {
				Integer position = memento.getInteger(TAG_HORIZONTAL_POSITION);
				if (position != null)
					bar.setSelection(position.intValue());
			}
		}
		getSite().setSelectionProvider(viewer);
		
		ISelectionListener listener = getPageSelectionListener();
		getSite().getPage().addSelectionListener(listener);
		listener.selectionChanged(getSite().getPage().getActivePart(),
				getSite().getPage().getSelection());
		viewer.addOpenListener(new IOpenListener() {