Bug 94459 [Undo] - should refactoring undo work when text undo limit is 0?
Refactoring undos are not showing up in the package explorer undo menu when the text undo limit is set to 0. Technically the refactoring operation should be permitted on the workspace undo context history. The history should just be removing the text context from the operation. One could argue this is a correctly working "feature" but need to check why it's happening and resolve the behavior as a bug or document as expected outcome.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/DefaultOperationHistory.java
* Check the redo limit before adding an operation. In theory the redo limit
	 * should never be reached, because the redo items are transferred from the
	 * undo history, which has the same limit. The redo history is cleared
	 * whenever a new operation is added. We check for completeness since
	 * implementations may change over time.
	 * 
	 * Return a boolean indicating whether the redo should proceed.
	 */
	private boolean checkRedoLimit(IUndoableOperation operation) {
		IUndoContext[] contexts = operation.getContexts();
		for (int i = 0; i < contexts.length; i++) {
			int limit = getLimit(contexts[i]);
			if (limit > 0) {
				forceRedoLimit(contexts[i], limit - 1);
			} else {
				return false;
			}
		}
		return true;
	}
	/**
	 * Check the undo limit before adding an operation. Return a boolean
	 * indicating whether the undo should proceed.
	 */
	private boolean checkUndoLimit(IUndoableOperation operation) {
		IUndoContext[] contexts = operation.getContexts();
		for (int i = 0; i < contexts.length; i++) {
			int limit = getLimit(contexts[i]);
			if (limit > 0) {
				forceUndoLimit(contexts[i], limit - 1);