[5.2] PHP Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated (#44876)

Author: alikon

libraries/src/Table/Category.php

@@ -172,7 +172,7 @@ public function check()
             return false;
         }
 
-        $this->alias = trim($this->alias);
+        $this->alias = trim($this->alias ?? '');
 
         if (empty($this->alias)) {
             $this->alias = $this->title;