Java 21 regression bug: in a .jsp, request.getUserPrincipal() returns null despite being logged in

[cyril-briquet]

When setting java21 in appengine-web.xml,
in a .jsp, the call request.getUserPrincipal() returns null despite being logged in.

[ludoch]

Both prod and local server?

[cyril-briquet]

Local server yes; production server I haven't tried.

[cyril-briquet]

Both prod and local server?

I've just tried on a prod server: the answer is yes, both indeed.

[lachlan-roberts]

Opened PR #243 to fix this.

[ludoch]

Code fix is now checked in.
Will reach prod end of next week or next (due to 4rth of July break in US).
Meanwhile, you can try following for the next few days https://github.com/GoogleCloudPlatform/appengine-java-standard/blob/main/TRYLATESTBITSINPROD.md from head (Sorry, Maven only, gradle contribution welcome).

[cyril-briquet]

Update: bug is fixed in local devserver, but not in production server

[ludoch]

A bit strange as the code area for the fix also applies to prod... Maybe one thing to try first is to go to the admin console, app engine instances page and try to kill whatever running instance you see to force a restart?

Restarts are not automatically done anymore...

[cyril-briquet]

Thanks for your rapid answer.

As suggested, I went to the admin console, AE instances page and killed the one instance that was running (apparently, it always restarts automatically even before I try to access the app in production as a user).

FWIW, here is the code that correctly displays the user's e-mail with the dev server and null with the prod server:

<%= (request.getUserPrincipal() != null) ? request.getUserPrincipal().getName() : "null" %>

[ludoch]

Thanks!
Sorry about that, we believe 3d53db9 should address it. Tested only manually, looking for a prod e2e test...

[cyril-briquet]

test-files.txt

Please find here as an attached file the source code of a test web app exercising the bug

[cyril-briquet]

Works for me: bug not observed any more on the production server.
Thanks for the patches.