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
try {
				int end= offset;
				IRegion endLine= document.getLineInformationOfOffset(end);
				int maxEnd= endLine.getOffset() + endLine.getLength();
				while (end != maxEnd && Character.isWhitespace(document.getChar(end)))
					++end;
				
				return end != maxEnd && document.getChar(end) == character;
			} catch (BadLocationException e) {
				
				return true;
			}			
		}
		
		/*
		 * @see org.eclipse.swt.custom.VerifyKeyListener#verifyKey(org.eclipse.swt.events.VerifyEvent)
		 */
		public void verifyKey(VerifyEvent event) {			
			if (!event.doit)
				return;
				
			final ISourceViewer sourceViewer= getSourceViewer();
			IDocument document= sourceViewer.getDocument();
			final Point selection= sourceViewer.getSelectedRange();
			final int offset= selection.x;
			final int length= selection.y;
			switch (event.character) {
			case '(':
				if (hasCharacterToTheRight(document, offset + length, '('))
					return;