bug #18243 Fixed a bug: saving with not serializable values (RedisAdapter) (masterklavi)

This PR was squashed before being merged into the 3.1-dev branch (closes #18243).

Discussion
----------

Fixed a bug: saving with not serializable values (RedisAdapter)

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | no
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Commits
-------

47f45b1 Fixed a bug: saving with not serializable values (RedisAdapter)

Author: nicolas-grekas

src/Symfony/Component/Cache/Adapter/RedisAdapter.php

@@ -90,22 +90,23 @@ protected function doDelete(array $ids)
      */
     protected function doSave(array $values, $lifetime)
     {
+        $serialized = array();
         $failed = array();
 
         foreach ($values as $id => $v) {
             try {
-                $values[$id] = serialize($v);
+                $serialized[$id] = serialize($v);
             } catch (\Exception $e) {
                 $failed[] = $id;
             }
         }
 
-        if (!$this->redis->mSet($values)) {
+        if (!$this->redis->mSet($serialized)) {
             return false;
         }
 
         if ($lifetime >= 1) {
-            foreach ($values as $id => $v) {
+            foreach ($serialized as $id => $v) {
                 $this->redis->expire($id, $lifetime);
             }
         }