Login: retain email address after failed Google login attempts

[nheagy]

Refs #7675

Small change so that we keep the Google email address of failed login attempts to prefill on subsequent login or signup screens.

To test:

• Use the Google button to login to a Google account with no associated WordPress.com account.
• On the error screen, pick an option and ensure that the Google email address is correctly prefilled
• Repeat for the other two options

Needs review: @aerych

[aerych]

I think we'd still want to do this from retryWithEmail... otherwise it might seem a bit weird to tap the "Try with another email" option and see that address in the text field.

[nheagy]

@aerych I agree! Also, turns out Signup wasn't working, still. Fixed that too.

Ready for a second look.

[aerych]

Nice.
I tested again and noticed that the email address was still being populated in the textfield even though its being unset in loginFields. It looks like configureEmailField is called by viewWillAppear when the Google controller is dismissed. So the email address is already present before the error screen is even shown. Should we add another call to configureEmailFieldin retryWithEmail so its removed?

[nheagy]

@aerych I'm only seeing the email get filled when tapping "Try with the site address" and "Sign up", which seems unavoidable. When tapping "Try with another email" it's being cleared for me. Can you double check what you're seeing?

Fwiw, the value is set to "" before dismiss() is called, which should then also be before viewWillAppear: is called.

[aerych]

Can you double check

Huh. I'm not seeing it now. :(

🤷‍♂️

then :) If its a heisenbug we'll worry about it if it reappears.

[nheagy]

Thanks, @aerych!