Bug 330803 SWTException from tool item dropdowns after closing/reopening perspectives
1. Click the 'Run' tool item's dropdown arrow. 2. Window > Close Perspective 3. Window > Open Perspective > Other... > Java 4. Repeat step 1. org.eclipse.swt.SWTException: Widget is disposed at org.eclipse.swt.SWT.error(SWT.java:4091) at org.eclipse.swt.SWT.error(SWT.java:4006) at org.eclipse.swt.SWT.error(SWT.java:3977) at org.eclipse.swt.widgets.Widget.error(Widget.java:468) at org.eclipse.swt.widgets.Widget.checkWidget(Widget.java:340) at org.eclipse.swt.widgets.Menu.setLocation(Menu.java:1427) at org.eclipse.e4.ui.workbench.renderers.swt.ToolItemRenderer$5.widgetSelected(ToolItemRenderer.java:315) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:234) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4084) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3675) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$6.run(PartRenderingEngine.java:780) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:696) at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:91)
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/ToolItemRenderer.java
return;
							}
							ParameterizedCommand cmd = item.getWbCommand();
							if (cmd == null) {
								cmd = generateParameterizedCommand(item,
										lclContext);
							}
							if (cmd == null) {
								return;
							}
							item.setEnabled(service.canExecute(cmd));
						}
						public void handleException(Throwable exception) {
							if (!logged) {
								logged = true;
								logger.error(
										exception,
										"Internal error during tool item enablement updating, this is only logged once per tool item."); 
							}
						}
					});
					
					display.timerExec(500, this);
				}
			});
			ti.addSelectionListener(new SelectionListener() {
				public void widgetSelected(SelectionEvent e) {
					if (e.detail != SWT.ARROW) {
						EHandlerService service = (EHandlerService) lclContext
								.get(EHandlerService.class.getName());