TypeError: Illegal offset type in isset or empty in FormValidator->performRequiredValidation()

I realize this will need tests.

MR appears to have failures

Most cases of tickets like these (illegal offset types) I've seen recommendations to backtrace to the point where it's suppose to be scarlar. To make sure we aren't masking a larger issue. But is possible this could be the correct approach in this case.

@smustgrave Thanks for taking a look. I believe this is correct in this case but thanks for checking. This case I know the user-input is the source of the problem which is in the issue summary. FYI it looks like this ?tags[0][0] to help read the URL encoding above.

This problem is discrete but part of a bigger set of attack vectors in the parent.

If you could point to a place where I can add a test case, that would really help me out. Otherwise I will take a horrible guess...

There's Drupal\Tests\Core\Form\FormValidatorTest we could probably expand on

Also can you rebase? I believe that random failure is fixed on head.

ramil g → made their first commit to this issue’s fork.

Added the test.

Thanks for adding a test to prove the problem exists and fixing my typo!

Committed and pushed b3ad358039 to 11.x and a0e23a634f to 11.0.x and 48de87ec1b to 10.4.x and f323ffae3d to 10.3.x. Thanks!

This replaces an error with a better message and a user can cause this with a crafted URL so this is a nice improvement. Backported to 10.3.x as a non-disruptive bugfix.

Automatically closed - issue fixed for 2 weeks with no activity.