PHP Warning: Undefined array key "language" in plugins/system/sef/src/Extension/Sef.php

[jjnxpct]

While running a multilingual Joomla 5.3.2 website on PHP 8.4.8, the following warnings appears in the server logs during normal frontend page access:

PHP Warning: Undefined array key "language" in /plugins/system/sef/src/Extension/Sef.php on line 122

Environment:
Joomla version: 5.3.2
PHP version: 8.4.8 (FPM under LiteSpeed)
Site setup: Multilingual site with SEF enabled
Plugin: System - SEF is enabled with default settings

Please let me know if further details are needed.

[richard67]

The fix could be to extend the if ($app->getLanguageFilter()) condition here https://github.com/joomla/joomla-cms/blob/5.3-dev/plugins/system/sef/src/Extension/Sef.php#L121-L124

so it is if ($app->getLanguageFilter() && isset($parsedVars['language'])) {

or maybe if ($app->getLanguageFilter() && !empty($parsedVars['language'])) {.

@Hackwar What do you recommend?

[Hackwar]

Sounds good.