Don’t bypass null values

Author: tillkruss

src/Illuminate/Database/Eloquent/Concerns/HasAttributes.php

@@ -471,14 +471,14 @@ protected function mutateAttributeForArray($key, $value)
      */
     protected function castAttribute($key, $value)
     {
-        if (is_null($value)) {
-            return $value;
-        }
-
         if ($this->isClassCastable($key)) {
             return $this->castToClass($key);
         }
 
+        if (is_null($value)) {
+            return $value;
+        }
+
         switch ($this->getCastType($key)) {
             case 'int':
             case 'integer':