Bug 17423 Revert apears twice in the popup menu.
Build F1. 1) Open a java editor. 2) Popup the menu. There is only one Revert option disable as it should be. 3) Make the editor dirty. 4) Popup the menu. There are two Revert option in the menu. One after UNDO and other before FORMAT.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
fCachedIsVerticalRulerVisible= (show && fCachedVerticalRuler != null);
			super.showAnnotations(show);
		}
		
		public IContentAssistant getContentAssistant() {
			return fContentAssistant;
		}
		
		/*
		 * @see ITextOperationTarget#doOperation(int)
		 */
		public void doOperation(int operation) {
		
			if (getTextWidget() == null)
				return;
			
			switch (operation) {
				case CONTENTASSIST_PROPOSALS:
					String msg= fContentAssistant.showPossibleCompletions();
					setStatusLineErrorMessage(msg);
					return;
			}
			
			super.doOperation(operation);
		}
		
		public void insertTextConverter(ITextConverter textConverter, int index) {
			throw new UnsupportedOperationException();
		}