Bug 13507 LinkedPositionUI has a reference to SWT.COLOR_RED
LinkedPositionUI(ITextViewer, LinkedPositionManager) - org.eclipse.jdt.internal.ui.text.link.LinkedPositionUI has a reference to SWT.COLOR_RED which will be unreadble if the user sets their background colour to Red. We will be adding a getErrorText colour to JFaceColours in build >20020411. You may want to use that.
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();
		}