Consider the case where you have a defaultText for navigator.notification.prompt, the user sees it and then hits enter.
So, if the user enters nothing you get the default value given as your value in result.
This is the expected behavior when mimicking this dialog.
To my surprise, this is not what happens with navigator.notification.prompt. If the user enters nothing then nothing is returned via results.input1. Although it looks like something is already "sitting" there and waiting for submit.
This bug might be related to https://issues.apache.org/jira/browse/CB-11214, where the reporter seems to expect the opposite (not sure about that).