[php-src] Issue #8279: mb_detect_encoding does not return the first matching encoding anymore

Issue: https://github.com/php/php-src/issues/8279 Author: come-nc ### Description The following code: ```php <?php $str = '/dav/files/admin/%C3%BC%C3%B6%C3%A4%C3%B6%C3%A4%C3%BC%C3%B6%C3%A4%C3%BB%C5%B7%C3%AE'; $rawstr = rawurldecode($str); var_dump( mb_detect_encoding($rawstr, ['UTF-8', 'ISO-8859-1']), mb_detect_encoding($rawstr, ['ISO-8859-1', 'UTF-8']), mb_check_encoding($rawstr, 'ISO-8859-1'), mb_check_encoding($rawstr, 'UTF-8'), ); ``` https://3v4l.org/kqHre Resulted in this output: ``` string(10) "ISO-8859-1" string(10) "ISO-8859-1" bool(true) bool(true) ``` But I expected this output instead: ``` string(5) "UTF-8" string(10) "ISO-8859-1" bool(true) bool(true) ``` It seems the behavior of mb_detect_encoding changed in PHP 8.1, not clear if this is on purpose or not. The documentation of mb_detect_encoding suggest that it will return the first matching encoding, which it does up until PHP 8.0 But with 8.1 it returns iso even if mb_check_encoding returns true for both utf and iso. ### PHP Version 8.1 ### Operating System _No response_