Weird new behavior when using `login: admin`

[Geoffrey Arnold]

Hello,

We're still trying to nail it down, but we're seeing weird new behavior when using `login: admin` in app.yaml to secure a route when a user is logged into multiple Google Accounts in their browser. Note that we are not using the IAP.

Previously, when a user was logged into multiple Google Accounts in their browser, GAE would prompt the user to choose the account when accessing a route secured with `login: admin`. 

Now, it appears that GAE is automatically using the first Google Account the user is logged into.

I've attempted to clear cookies/local storage for the site but no luck. I can't get GAE to prompt me to choose the account. I have only tested this in Chrome on OSX.

Any help would be greatly appreciated.

Geoff.

[Geoffrey Arnold]

Definitely an issue. I opened a ticket here:

https://issuetracker.google.com/issues/38506275

[Geoffrey Arnold]

Ok Google, authentication is broken for users that are logged into multiple Google Accounts in their browser when accessing App Engine apps that are using the Users API.

This seems like a fairly important issue.