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
interface ITextConverter {
		void customizeDocumentCommand(IDocument document, DocumentCommand command);
	};
	
	
	class AdaptedRulerLayout extends Layout {
		
		protected int fGap;
		protected AdaptedSourceViewer fAdaptedSourceViewer;
		
		
		protected AdaptedRulerLayout(int gap, AdaptedSourceViewer asv) {
			fGap= gap;
			fAdaptedSourceViewer= asv;
		}
		
		protected Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache) {
			Control[] children= composite.getChildren();
			Point s= children[children.length - 1].computeSize(SWT.DEFAULT, SWT.DEFAULT, flushCache);
			if (fAdaptedSourceViewer.isVerticalRulerVisible())
				s.x += fAdaptedSourceViewer.getVerticalRuler().getWidth() + fGap;
			return s;
		}