Merge branch '3.4' into 4.2

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

Author: nicolas-grekas

Legacy/CoverageListenerTrait.php

@@ -102,6 +102,16 @@ private function findSutFqcn($test)
         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) {

Legacy/SymfonyTestsListenerTrait.php

@@ -83,6 +83,16 @@ public function __construct(array $mockedNamespaces = array())
         }
     }
 
+    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) {