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
if (j == children.length) {
							
							if ((status & IJavaElementDelta.CHANGED) != 0 &&							
								(affectedDelta.getFlags() & IJavaElementDelta.F_MODIFIERS) != 0 &&
								!filtered(parent, affectedElement))
							{
								additions.addElement(affectedDelta);
							}
							continue;
						}
						item= children[j];
												    
						if ((status & IJavaElementDelta.REMOVED) != 0) {
							deletions.addElement(item);
							doUpdateParent= doUpdateParent || mustUpdateParent(affectedDelta, affectedElement);
												    
						} else if ((status & IJavaElementDelta.CHANGED) != 0) {
							int change= affectedDelta.getFlags();
							doUpdateParent= doUpdateParent || mustUpdateParent(affectedDelta, affectedElement);
							
							if ((change & IJavaElementDelta.F_MODIFIERS) != 0) {
								if (filtered(parent, affectedElement))
									deletions.addElement(item);
								else
									updateItem(item, affectedElement);
							}
							
							if ((change & IJavaElementDelta.F_CONTENT) != 0)
								updateItem(item, affectedElement);