MC-34657: Related products are missing in some products when importing products

Author: yelahin-serhiy

app/code/Magento/CatalogImportExport/Model/Import/Product/LinkProcessor.php

@@ -89,7 +89,6 @@ public function saveLinks(
         $resource = $this->linkFactory->create();
         $mainTable = $resource->getMainTable();
         $positionAttrId = [];
-        $nextLinkId = $this->resourceHelper->getNextAutoincrement($mainTable);
 
         // pre-load 'position' attributes ID for each link type once
         foreach ($this->linkNameToId as $linkId) {
@@ -103,6 +102,7 @@ public function saveLinks(
             $positionAttrId[$linkId] = $importEntity->getConnection()->fetchOne($select, $bind);
         }
         while ($bunch = $dataSourceModel->getNextBunch()) {
+            $nextLinkId = $this->resourceHelper->getNextAutoincrement($mainTable);
             $this->processLinkBunches($importEntity, $linkField, $bunch, $resource, $nextLinkId, $positionAttrId);
         }
     }

dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/ProductTest.php

@@ -3127,4 +3127,73 @@ public function testCheckDoubleImportOfProducts()
         $productsAfterSecondImport = $this->productRepository->getList($searchCriteria)->getItems();
         $this->assertCount(3, $productsAfterSecondImport);
     }
+
+    /**
+     * Checks that product related links added for all bunches properly after products import
+     */
+    public function testImportProductsWithLinksInDifferentBunches()
+    {
+        $this->importedProducts = [
+            'simple1',
+            'simple2',
+            'simple3',
+            'simple4',
+            'simple5',
+            'simple6',
+        ];
+        $importExportData = $this->getMockBuilder(Data::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $importExportData->expects($this->atLeastOnce())
+            ->method('getBunchSize')
+            ->willReturn(5);
+        $this->_model = $this->objectManager->create(
+            \Magento\CatalogImportExport\Model\Import\Product::class,
+            ['importExportData' => $importExportData]
+        );
+        $linksData = [
+            'related' => [
+                'simple1' => '2',
+                'simple2' => '1'
+            ]
+        ];
+        $pathToFile = __DIR__ . '/_files/products_to_import_with_related.csv';
+        $filesystem = $this->objectManager->create(Filesystem::class);
+
+        $directory = $filesystem->getDirectoryWrite(DirectoryList::ROOT);
+        $source = $this->objectManager->create(
+            Csv::class,
+            [
+                'file' => $pathToFile,
+                'directory' => $directory
+            ]
+        );
+        $errors = $this->_model->setSource($source)
+            ->setParameters(
+                [
+                    'behavior' => Import::BEHAVIOR_APPEND,
+                    'entity' => 'catalog_product'
+                ]
+            )
+            ->validateData();
+
+        $this->assertTrue($errors->getErrorsCount() == 0);
+        $this->_model->importData();
+
+        $resource = $this->objectManager->get(ProductResource::class);
+        $productId = $resource->getIdBySku('simple6');
+        /** @var Product $product */
+        $product = $this->objectManager->create(Product::class);
+        $product->load($productId);
+        $productLinks = [
+            'related' => $product->getRelatedProducts()
+        ];
+        $importedProductLinks = [];
+        foreach ($productLinks as $linkType => $linkedProducts) {
+            foreach ($linkedProducts as $linkedProductData) {
+                $importedProductLinks[$linkType][$linkedProductData->getSku()] = $linkedProductData->getPosition();
+            }
+        }
+        $this->assertEquals($linksData, $importedProductLinks);
+    }
 }

dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/_files/products_to_import_with_related.csv

@@ -0,0 +1,7 @@
+sku,product_type,store_view_code,name,price,qty,attribute_set_code,related_skus,related_position
+simple1,simple,,simple 1,25,10,Default,,
+simple2,simple,,simple 2,34,10,Default,,
+simple3,simple,,simple 3,58,10,Default,"simple1,simple2","1,2"
+simple4,simple,,simple 4,67,10,Default,"simple1,simple2","2,1"
+simple5,simple,,simple 5,58,10,Default,"simple1,simple2","1,2"
+simple6,simple,,simple 6,67,10,Default,"simple1,simple2","2,1"