Lots more convenient than clicking the little 'x', and it happens often enough that it would save time.
I am going to switch this to "Will not implement". In many cases the data that you are entering into modal dialogs is important, and accidentally hitting Esc would lose that information. For that reason we intentionally don't allow closing of the modal dialogs using the Esc key. This is a trade-off between convenience and safety, but experience has shown that in this case it is better to err on the side of safety.
Chris Waters: Aha! saves a draft of the modal description though, so even if a user did press Esc accidentally, when they return their text will still be there. See attached screenshot.
I often press Esc thinking that Aha! will close the modal. This is common behaviour for web apps, and would welcome it in Aha!.
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