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
ParameterizedCommand cmd = item.getWbCommand();
						if (cmd == null) {
							cmd = generateParameterizedCommand(item, lclContext);
						}
						if (cmd == null) {
							Activator.trace(Policy.DEBUG_MENUS,
									"Failed to execute: " + item.getCommand(), 
									null);
							return;
						}
						lclContext.set(MItem.class.getName(), item);
						service.executeHandler(cmd);
						lclContext.remove(MItem.class.getName());
					}
				}
				public void widgetDefaultSelected(SelectionEvent e) {
				}
			});
		}
	}
	/**
	 * @param mmenu
	 * @param shell
	 * @return
	 */
	protected Menu getMenu(MMenu mmenu, ToolItem toolItem) {
		Object obj = mmenu.getWidget();
		if (obj instanceof Menu) {
			return (Menu) obj;
		}