Bug 88352 Operation supports leaks contexts via action handler
I20050315-1100 Susan, this is a different leak from the one that I reported. Test Case: 1. open text editor 2. close text editor ==> DefaultUndoManager is leaked due to undo/redo actions handlers still holding on to the context.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
listeners.remove(listener);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#setLimit(org.eclipse.core.commands.operations.IUndoContext, int)
	 */
	public void setLimit(IUndoContext context, int limit) {
		Assert.isTrue(limit > 0);
		/*
		 * The limit checking methods interpret a null context as a global limit to be
		 * enforced.  We do not wish to support a global limit in this implementation,
		 * so we throw an exception for a null context.  The rest of the implementation
		 * can handle a null context, so subclasses can override this if a global limit
		 * is desired.
		 */	
		Assert.isNotNull(context);
		limits.put(context, new Integer(limit));
		forceUndoLimit(context, limit);
		forceRedoLimit(context, limit);
	}
	
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IOperationHistory#undo(org.eclipse.core.commands.operations.IUndoContext, org.eclipse.core.runtime.IProgressMonitor, org.eclipse.core.runtime.IAdaptable)
	 */
	public IStatus undo(IUndoContext context, IProgressMonitor monitor, IAdaptable info) throws ExecutionException{
		Assert.isNotNull(context);
		IUndoableOperation operation = getUndoOperation(context);