Merge branch '3.4' into 4.2

* 3.4:
  Prevent destructors with side-effects from being unserialized

src/Symfony/Bridge/PhpUnit/Legacy/CoverageListenerTrait.php

@@ -102,6 +102,16 @@ class CoverageListenerTrait
         return $sutFqcn;
     }
 
+    public function __sleep()
+    {
+        throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
+    }
+
+    public function __wakeup()
+    {
+        throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
+    }
+
     public function __destruct()
     {
         if (!$this->warnings) {

src/Symfony/Bridge/PhpUnit/Legacy/SymfonyTestsListenerTrait.php

@@ -83,6 +83,16 @@ class SymfonyTestsListenerTrait
         }
     }
 
+    public function __sleep()
+    {
+        throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
+    }
+
+    public function __wakeup()
+    {
+        throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
+    }
+
     public function __destruct()
     {
         if (0 < $this->state) {

src/Symfony/Bundle/FrameworkBundle/Tests/Kernel/ConcreteMicroKernel.php

@@ -64,6 +64,16 @@ class ConcreteMicroKernel extends Kernel implements EventSubscriberInterface
         return $this->cacheDir;
     }
 
+    public function __sleep()
+    {
+        throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
+    }
+
+    public function __wakeup()
+    {
+        throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
+    }
+
     public function __destruct()
     {
         $fs = new Filesystem();

src/Symfony/Component/Cache/Traits/FilesystemCommonTrait.php

@@ -122,6 +122,16 @@ trait FilesystemCommonTrait
         throw new \ErrorException($message, 0, $type, $file, $line);
     }
 
+    public function __sleep()
+    {
+        throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
+    }
+
+    public function __wakeup()
+    {
+        throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
+    }
+
     public function __destruct()
     {
         if (method_exists(parent::class, '__destruct')) {