Bug 33356 Read Only files: 2 dialogs from 'override methods' [code manipulation]
rc1 1. set a file to read-only 2. open the file in the editor, select an import statement 3. invoke 'override/implement methods' from the context menu 4. error dialog shows up, 'file is read only', press ok 5. second dialog comes up, invalid selection, select type...
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/OverrideMethodsAction.java
protected void run(IStructuredSelection selection) {
		Shell shell= getShell();
		try {
			IType type= getSelectedType(selection);
			if (type == null || !ElementValidator.check(type, getShell(), getDialogTitle(), false)) {
				return;
			}
			
			
			IEditorPart editor= EditorUtility.openInEditor(type);
			type= (IType)EditorUtility.getWorkingCopy(type);
			
			if (type == null) {
				MessageDialog.openError(shell, getDialogTitle(), ActionMessages.getString("OverrideMethodsAction.error.type_removed_in_editor")); 
				return;
			}
			
			run(shell, type, editor);
		} catch (CoreException e) {
			ExceptionHandler.handle(e, shell, getDialogTitle(), null); 
		}			
	}
	
	
	/* (non-Javadoc)
	 * Method declared on SelectionDispatchAction
	 */
	protected void selectionChanged(ITextSelection selection) {
	}