PHP Extension: add support for mbregex

[jakejackson1]

When the mbstring PHP extension is enabled, it would be useful to enable the multibyte regex functions, too. They are currently always disabled: https://github.com/WordPress/wordpress-playground/blob/trunk/packages/php-wasm/compile/Dockerfile#L509

[adamziel]

Thank you for reporting @jakejackson1! I understand your plugin relies on mbregex?

[jakejackson1]

@adamziel yes. The PDF library used in a plugin I help develop uses the mbregex functions. A couple of other popular plugins include the same PDF library:

https://wordpress.org/plugins/woocommerce-pdf-invoices-packing-slips/
https://wordpress.org/plugins/gravity-forms-pdf-extended/
https://wordpress.org/plugins/print-invoices-packing-slip-labels-for-woocommerce/

[adamziel]

PHP configuration–wise, the --enable-mbregex enables the mbregex extension.

However, mbregex requires the https://github.com/kkos/oniguruma library and it would have to be included as a dependency among other libraries already used (like libpng).

[MocioF]

My plugin still fails on activate with Uncaught Error: Call to undefined function mb_regex_encoding() in /wordpress/wp-content/plugins/no-unsafe-inline/vendor/voku/portable-utf8/src/voku/helper/UTF8.php:536

The issue seems to be confirmed, because in https://playground.wordpress.net/ if I activate the plugin phpinfo https://wordpress.org/plugins/phpinfo-wp/ ( using PHP VERSION 8.1.23-DEV) it shows me as Configure Command:

'./configure' 'PKG_CONFIG_PATH=/root/lib/lib/pkgconfig' '--disable-fiber-asm' '--enable-phar' '--enable-json' '--enable-embed=static' '--with-layout=GNU' '--disable-cgi' '--disable-all' '--enable-hash' '--enable-static=yes' '--enable-shared=no' '--enable-session' '--enable-filter' '--enable-calendar' '--disable-rpath' '--disable-phpdbg' '--without-pear' '--with-valgrind=no' '--without-pcre-jit' '--enable-bcmath' '--enable-ctype' '--enable-tokenizer' '--with-zlib' '--with-zlib-dir=/root/lib' '--with-zip' '--disable-cli' '--enable-libxml' '--with-libxml' '--with-libxml-dir=/root/lib' '--enable-dom' '--enable-xml' '--enable-simplexml' '--enable-xmlreader' '--enable-xmlwriter' '--with-sqlite3' '--enable-pdo' '--with-pdo-sqlite=/root/lib' '--with-png-dir=/root/lib' '--with-gd' '--enable-gd' '--with-openssl' '--with-openssl-dir=/root/lib' '--with-iconv=/root/lib' '--enable-mbstring' '--disable-mbregex'

[adamziel]

It seems like a regression, thank you for reporting @MocioF. I've added this issue to the project board with a high priority. Let's include a unit test with the fix to ensure the mbregex extension keeps working over time.

[bgrgicak]

The issue is in this if. PHP versions can be 8.0.30 and this doesn't work.

I have a fix and am working on some tests to ensure it doesn't break again.