Bug 72024 UndoManager creates potential memory leak [refactoring]
3.0 The refactoring undo manager doesn't call dispose in all cases where a undo/redo object is no longer needed. This can result in a memory leak since the undo/redo object could register for listeners and therefore relies on the fact the dispose is called correctly. Cases where dispose isn't called: - if the undo stack reaches it maximum number of change objects and the last one is removed from the stack. - if the undo/redo stack gests flushed and one of the change objects causes an exception during sending dispose. - if the undo/redo object isn't valid anymore and can therefore not be executed.
org.eclipse.ltk.ui.refactoring/src/org/eclipse/ltk/ui/refactoring/RefactoringWizard.java
RefactoringStatus status= getConditionCheckingStatus();
		
		
		if (change == null && status == null) {		
			internalSetChange(InternalAPI.INSTANCE, change);
			return caller;
		}
				
		
		if (!status.hasFatalError())
			internalSetChange(InternalAPI.INSTANCE, change);
		
		if (status.isOK()) {
			return getPage(IPreviewWizardPage.PAGE_NAME);
		} else {
			return getPage(ErrorWizardPage.PAGE_NAME);
		}
	} 
	
	/**
	 * {@inheritDoc}
	 */
	public boolean canFinish() {
		if (fForcePreviewReview && !fPreviewShown)
			return false;
		return super.canFinish();
	}
	
	 final RefactoringStatus checkFinalConditions() {