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
}
			}
			
			switch (event.character) {	
			case '\b': {
				Position p= manager.getFirstPosition();	
				if (p.offset == offset && p.length == length)
					return new ExitFlags(0, false);
				else
					return null;
			}
			case '\n':
			case '\r':
				return new ExitFlags(LinkedPositionUI.COMMIT, true);
				
			default:
				return null;
			}						
		}
		private boolean isMasked(int offset) {
			IDocument document= getSourceViewer().getDocument();
			try {
				return fEscapeCharacter == document.getChar(offset - 1);
			} catch (BadLocationException e) {
			}
			return false;
		}
	};
	
	private static class BracketLevel {