\Drupal\dblog\Controller\DbLogController::createLink() can cause deprecations on PHP 8.1

The value of $uri goes into a preg_match() function as the second parameter (in the method isValid()) and that must be a string in PHP 8.1.
Looks good to me.

::createLink() is only called in two places, can we fix the callers instead?

I think the approach in #3 is correct, given this is a bad use of the UrlHelper::isValid API (which expects a string). Also the method still does what the documentation of that method says it does.

But also inspecting the code of the UrlHelper there are other examples of methods that expect a string but does not specify the full type-hint. I guess this is what is discussed here #3050720: [Meta] Implement strict typing in existing code

@catch +1 RTBC as this protected method expects to deal with NULL as it documents in its doc-block

OK, fair enough.

Committed 09cf315 and pushed to 9.3.x. Thanks!