Bug 33389 Read-Only files: Quick fix enabled and gets checkmark!
RC1 1. set a file to ready only. 2. Open the file an set the cursor inside 3. Open the 'Edit' menu. Note that 'Quick fix' is enabled, but 'Content assist' is not 4. Choose 'Quick fix' 5. Open the context menu: Quick fix got a checkmark!
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
return super.requestWidgetToken(requester);
		}
		/*
		 * @see org.eclipse.jface.text.source.ISourceViewer#configure(org.eclipse.jface.text.source.SourceViewerConfiguration)
		 */
		public void configure(SourceViewerConfiguration configuration) {
			super.configure(configuration);
			fCorrectionAssistant= new JavaCorrectionAssistant(CompilationUnitEditor.this);
			fCorrectionAssistant.install(this);
			prependAutoEditStrategy(new SmartBracesAutoEditStrategy(this), IDocument.DEFAULT_CONTENT_TYPE);
		}
	};
	
	static class TabConverter implements ITextConverter {
		
		private int fTabRatio;
		private ILineTracker fLineTracker;
		
		public TabConverter() {
		} 
		
		public void setNumberOfSpacesPerTab(int ratio) {
			fTabRatio= ratio;
		}
		
		public void setLineTracker(ILineTracker lineTracker) {
			fLineTracker= lineTracker;
		}
		
		private int insertTabString(StringBuffer buffer, int offsetInLine) {