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
/**
	 * Returns the offset of the given Java element.
	 */
	private int getOffset(IJavaElement element) {
		if (element instanceof ISourceReference) {
			ISourceReference sr= (ISourceReference) element;
			try {
				ISourceRange srcRange= sr.getSourceRange();
				if (srcRange != null)
					return srcRange.getOffset();
			} catch (JavaModelException e) {
			}
		}
		return -1;	
	}
	
	/*
	 * @see AbstractTextEditor#rememberSelection()
	 */
	protected void rememberSelection() {
		ISelectionProvider sp= getSelectionProvider();
		fRememberedSelection= (sp == null ? null : (ITextSelection) sp.getSelection());
		if (fRememberedSelection != null) {
			fRememberedElement= getElementAt(fRememberedSelection.getOffset(), true);
			fRememberedElementOffset= getOffset(fRememberedElement); 
		}
	}
	
	/*