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
if (mmenu instanceof MRenderedMenu) {
			obj = ((MRenderedMenu) mmenu).getContributionManager();
			if (obj instanceof IContextFunction) {
				final IEclipseContext lclContext = getContext(mmenu);
				obj = ((IContextFunction) obj).compute(lclContext);
				((MRenderedMenu) mmenu).setContributionManager(obj);
			}
			if (obj instanceof IMenuCreator) {
				final IMenuCreator creator = (IMenuCreator) obj;
				final Menu menu = creator.getMenu(toolItem.getParent()
						.getShell());
				if (menu != null) {
					toolItem.addDisposeListener(new DisposeListener() {
						public void widgetDisposed(DisposeEvent e) {
							if (menu != null && !menu.isDisposed()) {
								creator.dispose();
							}
						}
					});
					mmenu.setWidget(menu);
					menu.setData(AbstractPartRenderer.OWNING_ME, menu);
					return menu;
				}
			}
		}
		return null;
	}
}