Bug 17292 Inconsistent Undo behaviour for Cut/Copy/Paste in outline
Build 20020521 (freeze 1) 1) Open a java editor on some class 2) In the content outline, select a method and do Ctrl+X to cut 3) Notice in the menus, Edit->Undo and Refactor->Undo are disabled 4) Now select the type node in the content outline, and Ctrl+V to paste 5) Still, neither Undo action is enabled 6) Now click inside the editor area to give it focus. 7) Now "Edit->Undo" is possible. So, the problems are: 1) Undo is not consistent, it's available for Paste but not Cut. 2) Even when undo is possible, it only becomes enabled when the editor is activated.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaOutlinePage.java
Enumeration e= deletions.elements();
					while (e.hasMoreElements()) {
						item= (Item) e.nextElement();
						disassociate(item);
						item.dispose();
					}
					
					if (doUpdateParent)
						updateItem(w, delta.getElement());
				}
				
								
				/*
				 * @see ContentViewer#handleLabelProviderChanged(LabelProviderChangedEvent)
				 */
				protected void handleLabelProviderChanged(LabelProviderChangedEvent event) {
					Object input= getInput();
					if (event instanceof ProblemsLabelChangedEvent) {
						ProblemsLabelChangedEvent e= (ProblemsLabelChangedEvent) event;
						if (e.isMarkerChange() && input instanceof ICompilationUnit) {
							return; 
						}
					}
					
					Object[] changed= event.getElements();
					if (changed != null) {
						IResource resource= getUnderlyingResource();
						if (resource != null) {
							for (int i= 0; i < changed.length; i++) {
								if (changed[i].equals(resource)) {