Fix the handling of `NULL` values

See https://www.woltlab.com/community/thread/300917-neue-benutzergruppe-anlegen-funktioniert-nicht-mit-php-8-1x/

diff --git a/wcfsetup/install/files/lib/system/option/LineBreakSeparatedTextOptionType.class.php b/wcfsetup/install/files/lib/system/option/LineBreakSeparatedTextOptionType.class.php
index 2144c49ae4c18ecad5cd7cf389809d99485b2f5b..b6d71658e5ecf660aaffcdb5e982d398f5a0a147 100644 (file)
--- a/wcfsetup/install/files/lib/system/option/LineBreakSeparatedTextOptionType.class.php
+++ b/wcfsetup/install/files/lib/system/option/LineBreakSeparatedTextOptionType.class.php
@@ -23,7 +23,7 @@ class LineBreakSeparatedTextOptionType extends TextareaOptionType
      */
     public function getFormElement(Option $option, $value)
     {
-        $values = ArrayUtil::trim(\explode("\n", StringUtil::unifyNewlines($value)));
+        $values = ArrayUtil::trim(\explode("\n", StringUtil::unifyNewlines($value ?? '')));
         \uasort($values, 'strnatcmp');
 
         static $identifiers = [];