Fatal error when $config->pageNameWhitelist leave blank and $config->pageNameCharset = UTF8 if use non ASCII characters in page name.

[gideonso]

SYMPTOM

When creating or editing a page with Chinese characters in the page name
(e.g., 關於我們) while $config->pageNameCharset = "UTF8" and
$config->pageNameWhitelist = "" (empty), a fatal error occurs:

Fatal Error: Uncaught ValueError: idn_to_ascii(): Argument #1 ($domain)
must not be empty in Sanitizer.php:1138

Environment

PHP 8.4
ProcessWire 2.6.260

[ryancramerdesign]

This was a PHP 8.4 regression — prior versions of PHP had idn_to_ascii() return false gracefully when passed an empty string, but PHP 8.4 changed it to throw a ValueError instead. The fix adds a guard to return early before calling idn_to_ascii() if the value is empty (commit 10b27a69).

One note: an empty $config->pageNameWhitelist is a configuration error when using UTF8 page names. Any characters you want to allow in page names need to be present in the whitelist — with an empty whitelist, all non-ASCII characters will be stripped to dashes when generating a page name from a title. You would want to add the characters you need (e.g. Chinese/CJK characters) to your pageNameWhitelist in /site/config.php.

-Claude

[gideonso]

Hi Ryan,

Thanks for the quick response. About leaving pagenamewhitelist blank, it is advised by you when we discussed about supporting Chinese in page name. It is not possible to put in about 20000 Chinese characters to the config.PHP file.

I manage to make the Sanitizer to check the pagename against a range of utf8 code if pagenamewhitelist leave blank.