Firebaseui-android: "Code: 8 Message: 8" error when double tapping "Sign In" button

[hendrep]

Step 2: Describe your environment

• Android device: Samsung A3 and Xiaomi A1 (not tested on other devices yet)
• Android OS version: 7 and 8.1
• Google Play Services version: 4.0.1
• Firebase/Play Services SDK version: 16.04
• FirebaseUI version: 4.2.1

Step 3: Describe the problem:

FirebaseUI reverts to main screen with toast: "Code: 8 Message: 8" when "Sign-In" button is tapped twice on the "You already have an account screen"

Steps to reproduce:

1. Sign up with Google account
2. Sign in with email option
3. On "You already have an account" screen, tap sign in button twice

Sometimes there is a bit of a delay and user thinks that they did not tap the button, resulting in this behaviour.

Observed Results:

Code: 8, Message: 8 toast is displayed and UI reverts to main screen.

Expected Results:

User should not be able to double tap the sign-in button.

[samtstern]

@hendrep thanks for this! I was able to reproduce the bug.

[samtstern]

Fixing this in #1541

[samtstern]

This has been released in version 4.3.0.