MAGETWO-52836: Enable EAV attributes caching

Author: akaplya

app/code/Magento/Catalog/Model/Product/Copier.php

@@ -75,7 +75,7 @@ public function copy(\Magento\Catalog\Model\Product $product)
                 : $urlKey . '-1';
             $duplicate->setUrlKey($urlKey);
             try {
-                $duplicate->save($duplicate);
+                $duplicate->save();
                 $isDuplicateSaved = true;
             } catch (\Magento\Framework\Exception\AlreadyExistsException $e) {
             }

app/code/Magento/Customer/Model/Metadata/CachedMetadata.php

@@ -102,7 +102,7 @@ public function getCustomAttributesMetadata($dataObjectClassName = null)
      * @return AttributeCache
      * @deprecated
      */
-    protected function getCache()
+    private function getCache()
     {
         if (!$this->cache) {
             $this->cache = ObjectManager::getInstance()->get(AttributeCache::class);

app/code/Magento/Eav/Test/Unit/Model/ResourceModel/Entity/AttributeTest.php

@@ -22,7 +22,7 @@ class AttributeTest extends \PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        $this->markTestSkipped();
+        $this->markTestSkipped('Unreliable implementation, MAGETWO-52857');
         $this->contextMock = $this->getMock(
             '\Magento\Framework\Model\Context',
             ['getCacheManager', 'getEventDispatcher', 'getLogger', 'getAppState', 'getActionValidator'],

dev/tests/integration/testsuite/Magento/Catalog/Ui/DataProvider/Product/Form/Modifier/EavTest.php

@@ -75,7 +75,6 @@ public function testModifyMeta()
      */
     public function testModifyData()
     {
-        $this->markTestSkipped();
         /** @var \Magento\Catalog\Model\Product $product */
         $product = $this->objectManager->create(\Magento\Catalog\Model\Product::class);
         $product->load(1);