Fixes #3817: `yii\rbac\PhpManager::getChildren()` returns null instead of expected empty array

framework/CHANGELOG.md

@@ -44,6 +44,7 @@ Yii Framework 2 Change Log
 - Bug #3751: Fixed postgreSQL schema data for enum values, do not add values if there are none (makroxyz)
 - Bug #3752: `QueryBuilder::batchInsert()` does not typecast input values (qiangxue)
 - Bug #3756: Fix number formatting error for `\yii\base\Formatter` by converting strings to float (kartik-v)
+- Bug #3817: `yii\rbac\PhpManager::getChildren()` returns null instead of expected empty array (qiangxue)
 - Bug: Fixed inconsistent return of `\yii\console\Application::runAction()` (samdark)
 - Bug: URL encoding for the route parameter added to `\yii\web\UrlManager` (klimov-paul)
 - Bug: Fixed the bug that requesting protected or private action methods would cause 500 error instead of 404 (qiangxue)

framework/rbac/PhpManager.php

@@ -410,7 +410,7 @@ class PhpManager extends BaseManager
      */
     public function getChildren($name)
     {
-        return (isset($this->_children[$name])) ? $this->_children[$name] : null;
+        return isset($this->_children[$name]) ? $this->_children[$name] : [];
     }
 
     /**