bug #39794 Dont allow unserializing classes with a destructor - 4.4 (jderusse)

This PR was merged into the 4.4 branch.

Discussion
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Dont allow unserializing classes with a destructor - 4.4

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

Prevent destructors with side-effects from being unserialized

Commits
-------

955395c999 Dont allow unserializing classes with a destructor - 4.4

Author: nicolas-grekas

Transport/Smtp/SmtpTransport.php

@@ -340,6 +340,16 @@ private function checkRestartThreshold(): void
         $this->restartCounter = 0;
     }
 
+    public function __sleep()
+    {
+        throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
+    }
+
+    public function __wakeup()
+    {
+        throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
+    }
+
     public function __destruct()
     {
         $this->stop();