MAGETWO-67745: The "Catalog Search indexer process unknown error" appears after reindex

Author: arnie1947

app/code/Magento/Catalog/Model/ProductRepository.php

@@ -308,7 +308,7 @@ private function cacheProduct($cacheKey, \Magento\Catalog\Api\Data\ProductInterf
 
         if ($this->cacheLimit && count($this->instances) > $this->cacheLimit) {
             $offset = round($this->cacheLimit / -2);
-            $this->instancesById = array_slice($this->instancesById, $offset);
+            $this->instancesById = array_slice($this->instancesById, $offset, null, true);
             $this->instances = array_slice($this->instances, $offset);
         }
     }

app/code/Magento/Catalog/Test/Unit/Model/ProductRepositoryTest.php

@@ -153,6 +153,13 @@ class ProductRepositoryTest extends \PHPUnit_Framework_TestCase
      */
     private $serializerMock;
 
+    /**
+     * Product repository cache limit.
+     *
+     * @var int
+     */
+    private $cacheLimit = 2;
+
     /**
      * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
      */
@@ -337,6 +344,7 @@ function ($value) {
                 'mediaGalleryProcessor' => $this->mediaGalleryProcessor,
                 'collectionProcessor' => $this->collectionProcessorMock,
                 'serializer' => $this->serializerMock,
+                'cacheLimit' => $this->cacheLimit
             ]
         );
     }
@@ -469,6 +477,60 @@ public function testGetByIdForcedReload()
         $this->assertEquals($this->productMock, $this->model->getById($identifier, $editMode, $storeId, true));
     }
 
+    /**
+     * Test for getById() method if we try to get products when cache is already filled and is reduced.
+     *
+     * @return void
+     */
+    public function testGetByIdWhenCacheReduced()
+    {
+        $result = [];
+        $expectedResult = [];
+        $productsCount = $this->cacheLimit * 2;
+
+        $productMocks =  $this->getProductMocksForReducedCache();
+        $productFactoryInvMock = $this->productFactoryMock->expects($this->exactly($productsCount))
+            ->method('create');
+        call_user_func_array([$productFactoryInvMock, 'willReturnOnConsecutiveCalls'], $productMocks);
+        $this->serializerMock->expects($this->atLeastOnce())->method('serialize');
+
+        for ($i = 1; $i <= $productsCount; $i ++) {
+            $product = $this->model->getById($i, false, 0);
+            $result[] = $product->getId();
+            $expectedResult[] = $i;
+        }
+
+        $this->assertEquals($expectedResult, $result);
+    }
+
+    /**
+     * Get product mocks for testGetByIdWhenCacheReduced() method.
+     *
+     * @return array
+     */
+    private function getProductMocksForReducedCache()
+    {
+        $productMocks = [];
+
+        for ($i = 1; $i <= $this->cacheLimit * 2; $i ++) {
+            $productMock = $this->getMockBuilder(\Magento\Catalog\Model\Product::class)
+                ->disableOriginalConstructor()
+                ->setMethods([
+                    'getId',
+                    'getSku',
+                    'load',
+                    'setData',
+                ])
+                ->getMock();
+            $productMock->expects($this->once())->method('load');
+            $productMock->expects($this->atLeastOnce())->method('getId')->willReturn($i);
+            $productMock->expects($this->atLeastOnce())->method('getSku')->willReturn($i . uniqid());
+            $productMocks[] = $productMock;
+        }
+
+        return $productMocks;
+    }
+
     /**
      * Test forceReload parameter
      *