Deprecations for preg_match, preg_replace_callback and null argument

[derikb]

Seeing this in php8.2

1 PHP Deprecated:  preg_replace_callback(): Passing null to parameter #3 ($subject) of type array|string is deprecated in /vendor/ezyang/htmlpurifier/library/HTMLPurifier/Lexer/DOMLex.php on line 57
1 PHP Deprecated:  preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /vendor/ezyang/htmlpurifier/library/HTMLPurifier/Lexer.php on line 373
1 PHP Deprecated:  preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /vendor/ezyang/htmlpurifier/library/HTMLPurifier/Encoder.php on line 139

Looks like all are cases of the code expecting a string but somewhere allowing null.

php docs do not indicate when this was deprecated, just indicates those parameters should be string|array.

Probably somewhere further up the stack a null check could clear this up.