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.core.refactoring/src/org/eclipse/ltk/internal/core/refactoring/UndoManager.java
private Stack fUndoChanges;
	private Stack fRedoChanges;
	private Stack fUndoNames;
	private Stack fRedoNames;
	private ListenerList fListeners;
	
	private static final int MAX_UNDO_REDOS= 6;
	
	private static class NullQuery implements IValidationCheckResultQuery {