Steps to replicate the issue (include links if applicable):
Given code of the form
$someParam = $request->getFuzzyBool( 'someparam', true );
where $request is a WebRequest, a deprecation warning will be emitted on PHP 8.1 or newer:
PHP Deprecated: strcasecmp(): Passing null to parameter #1 ($string1) of type string is deprecated in /includes/WebRequest.php on line 677 #0 [internal function]: MWExceptionHandler::handleError(integer, string, string, integer) #1 /includes/WebRequest.php(677): strcasecmp(NULL, string) [...code that called getFuzzyBool]