Validating a checkbox with Alt-Enter makes it return the empty string

[Arpafaucon]

Describe the bug

First of all: thanks for maintaining this package ! I was veeery happy when I managed to make it work, and it saved us a lot of time by making multiple python scripts intuitively interactive ! ❤️

Context

I have implemented a form using questionary with 2 questions

• a multi-line text prompt (that you have to validate with Alt-Enter )
• a checkbox presenting a set of tags

When my users want to go too fast, they press Alt-Enter twice and this trigger a strange behavior

• the first time validates the multi-line text prompt
• so the checkbox form is shown
• the second time is caught by the checkbox form
• and it reacts by returning the empty string ''

We noticed this because the empty string is not even a list, so code breaks further down

Investigation

• bug appears on versions 1.10.0 and 2.0.1
• I had a look at the source code, trying to find how the keybinding logic works
  • I don't see any reference to either <Enter> or <Alt-Enter> in questionary code - but I might be looking for the wrong patterns
  • With a grep "Alt+Enter" -R in the prompt toolkit source code , I see that there are some emacs keybing config. However, the bug persists with use_emacs_keys=False

Example

import questionary

q = questionary.checkbox("Press Alt-Enter here", choices=[
    questionary.Choice(a, value=a)
    for a in "abc"
]).ask()

print(repr(q))

Steps to reproduce

1. Write down the script above in a file, and run it
2. When shown the checkbox form, select whatever choices you like
3. Instead of pressing <Enter> to validate it
   • press <Alt-Enter>
   • OR press <Esc> then <Enter>
4. On my machine, this will exit the checkbox form and print(repr(q)) will print ''

Expected behaviour

• <Alt-Enter>/ <Esc + Enter> should not trigger any reaction
• or it should behave like <Enter> and return the currently selected list
• or raise an exception ?

Latest version

• I have checked that this issue occurs on the latest version of questionary.

Questionary version

2.0.1

Prompt Toolkit version

3.0.36

Operating System

Linux