Bug 66923 [typing]Can delete word (Ctrl-Backspace) on read only file
When you open read-only java file, all editing functions are disabled except deleting with Ctrl-Backspace and Ctrl-Del, then it is imposible to save this file. On simple text file it works ok - it blocks all edditing functions (including Ctrl-Backspace). I am using build 200406111814
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
if (text == null || text.isDisposed())
				return;
			
			
			int offset= 0;
			int length= 0;
			if (viewer instanceof ITextViewerExtension5) {
				ITextViewerExtension5 extension= (ITextViewerExtension5) viewer;
				IRegion widgetRange= extension.modelRange2WidgetRange(region);
				if (widgetRange == null)
					return;
					
				offset= widgetRange.getOffset();
				length= widgetRange.getLength();
				
			} else {
				offset= region.getOffset() - viewer.getVisibleRegion().getOffset();
				length= region.getLength();
			}
			text.redrawRange(offset, length, false);
			
			
			fActiveRegion= region;
			if (viewer instanceof ITextViewerExtension2)
				((ITextViewerExtension2) viewer).invalidateTextPresentation(region.getOffset(), region.getLength());
			else
				viewer.invalidateTextPresentation();
		}
		
		private void activateCursor(ISourceViewer viewer) {