From c33ef022fe6aee52aa6d0880fda89fe213d7a71a Mon Sep 17 00:00:00 2001
From: Samuele Renati <samuele.renati@gmail.com>
Date: Mon, 14 Nov 2022 09:39:41 +0100
Subject: [PATCH] Fix #19670: Fix Error null check PHP 8.1 `yii\rbac\DbManager`

---
 framework/CHANGELOG.md       |  1 +
 framework/rbac/DbManager.php | 12 +++++++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index e710d20580..b5e73be769 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -17,6 +17,7 @@ Yii Framework 2 Change Log
 - Bug #19316: Fix MysqlMutex with same connection but difference database (kamarton)
 - Bug #19507: Fix eager loading of nested one-to-many relations (spo0okie)
 - Bug #19546: Reverted #19309 (bizley)
+- Bug #19670: Fix Error null check PHP 8.1 `yii\rbac\DbManager` (samuelexyz)
 - Bug #19520: Fix for TIMESTAMP & ROWVERSION columns in MSSQL insert query (darkdef)
 
 
diff --git a/framework/rbac/DbManager.php b/framework/rbac/DbManager.php
index eb7a86e8cf..a733f3c57f 100644
--- a/framework/rbac/DbManager.php
+++ b/framework/rbac/DbManager.php
@@ -654,7 +654,9 @@ class DbManager extends BaseManager
         if (is_resource($data)) {
             $data = stream_get_contents($data);
         }
-
+        if ($data === null) {
+            return null;
+        }
         return unserialize($data);
     }
 
@@ -675,7 +677,9 @@ class DbManager extends BaseManager
             if (is_resource($data)) {
                 $data = stream_get_contents($data);
             }
-            $rules[$row['name']] = unserialize($data);
+            if ($data) {
+                $rules[$row['name']] = unserialize($data);
+            }
         }
 
         return $rules;
@@ -1013,7 +1017,9 @@ class DbManager extends BaseManager
             if (is_resource($data)) {
                 $data = stream_get_contents($data);
             }
-            $this->rules[$row['name']] = unserialize($data);
+            if ($data) {
+                $this->rules[$row['name']] = unserialize($data);
+            }
         }
 
         $query = (new Query())->from($this->itemChildTable);