[Cache] Fallback to positional when keyed results are broken

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

@@ -266,6 +266,9 @@ abstract class AbstractAdapter implements AdapterInterface, LoggerAwareInterface
 
         try {
             foreach ($items as $id => $value) {
+                if (!isset($keys[$id])) {
+                    $id = key($keys);
+                }
                 $key = $keys[$id];
                 unset($keys[$id]);
                 yield $key => $f($key, $value, true);

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

@@ -19,6 +19,18 @@ class MemcachedAdapter extends AbstractAdapter
 
     protected $maxIdLength = 250;
 
+    /**
+     * Constructor.
+     *
+     * Using a MemcachedAdapter with a TagAwareAdapter for storing tags is discouraged.
+     * Using a RedisAdapter is recommended instead. If you cannot do otherwise, be aware that:
+     * - the Memcached::OPT_BINARY_PROTOCOL must be enabled
+     *   (that's the default when using MemcachedAdapter::createConnection());
+     * - tags eviction by Memcached's LRU algorithm will break by-tags invalidation;
+     *   your Memcached memory should be large enough to never trigger LRU.
+     *
+     * Using a MemcachedAdapter as a pure items store is fine.
+     */
     public function __construct(\Memcached $client, $namespace = '', $defaultLifetime = 0)
     {
         $this->init($client, $namespace, $defaultLifetime);

src/Symfony/Component/Cache/Simple/AbstractCache.php

@@ -162,6 +162,9 @@ abstract class AbstractCache implements CacheInterface, LoggerAwareInterface
     {
         try {
             foreach ($values as $id => $value) {
+                if (!isset($keys[$id])) {
+                    $id = key($keys);
+                }
                 $key = $keys[$id];
                 unset($keys[$id]);
                 yield $key => $value;

src/Symfony/Component/Cache/Tests/Adapter/TraceableTagAwareAdapterTest.php

@@ -15,6 +15,9 @@ use Symfony\Component\Cache\Adapter\FilesystemAdapter;
 use Symfony\Component\Cache\Adapter\TagAwareAdapter;
 use Symfony\Component\Cache\Adapter\TraceableTagAwareAdapter;
 
+/**
+ * @group time-sensitive
+ */
 class TraceableTagAwareAdapterTest extends TraceableAdapterTest
 {
     public function testInvalidateTags()

src/Symfony/Component/Cache/Tests/Simple/CacheTestCase.php

@@ -15,6 +15,15 @@ use Cache\IntegrationTests\SimpleCacheTest;
 
 abstract class CacheTestCase extends SimpleCacheTest
 {
+    public static function validKeys()
+    {
+        if (defined('HHVM_VERSION')) {
+            return parent::validKeys();
+        }
+
+        return array_merge(parent::validKeys(), array(array("a\0b")));
+    }
+
     public function testDefaultLifeTime()
     {
         if (isset($this->skippedTests[__FUNCTION__])) {