[#18269] If import product has missing categories, make a lookup for existing categories to keep the correct url rewrites

app/code/Magento/CatalogUrlRewrite/Observer/AfterImportDataObserver.php

@@ -221,6 +221,7 @@ public function execute(Observer $observer)
 
     /**
      * Create product model from imported data for URL rewrite purposes.
+     * Also make a lookup for existing categories for this product if no categories are provided.
      *
      * @param array $rowData
      *
@@ -248,7 +249,13 @@ protected function _populateForUrlGeneration($rowData)
             }
         }
 
-        $this->categoryCache[$rowData['entity_id']] = $this->import->getProductCategories($rowData['sku']);
+        // If no categories are provided get the actual categories for product to prevent loss of existing rewrites
+        $productCategoryCache = $this->import->getProductCategories($rowData['sku']);
+        if (!isset($rowData['categories']) && !$productCategoryCache) {
+            $productCategoryCache = $product->getCategoryIds();
+        }
+
+        $this->categoryCache[$rowData['entity_id']] = $productCategoryCache;
         $this->websiteCache[$rowData['entity_id']] = $this->import->getProductWebsites($rowData['sku']);
         foreach ($this->websiteCache[$rowData['entity_id']] as $websiteId) {
             if (!isset($this->websitesToStoreIds[$websiteId])) {
@@ -436,6 +443,8 @@ protected function currentUrlRewritesRegenerate()
     }
 
     /**
+     * Generate URL Rewrites for Autogenerated URL
+     *
      * @param UrlRewrite $url
      * @param Category $category
      * @return array
@@ -470,6 +479,8 @@ protected function generateForAutogenerated($url, $category)
     }
 
     /**
+     * Generate url for given category
+     *
      * @param UrlRewrite $url
      * @param Category $category
      * @return array
@@ -503,6 +514,8 @@ protected function generateForCustom($url, $category)
     }
 
     /**
+     * Loads the category by url just from given metadata
+     *
      * @param UrlRewrite $url
      * @return Category|null|bool
      */
@@ -517,6 +530,8 @@ protected function retrieveCategoryFromMetadata($url)
     }
 
     /**
+     * Check whether Category is proper for generation or not
+     *
      * @param \Magento\Catalog\Model\Category $category
      * @param int $storeId
      * @return bool

app/code/Magento/CatalogUrlRewrite/Test/Unit/Observer/AfterImportDataObserverTest.php

@@ -315,12 +315,14 @@ public function testAfterImportData()
             ->expects($this->exactly(1))
             ->method('getStoreIdByCode')
             ->will($this->returnValueMap($map));
+
         $product = $this->createPartialMock(\Magento\Catalog\Model\Product::class, [
                 'getId',
                 'setId',
                 'getSku',
                 'setStoreId',
                 'getStoreId',
+                'getCategoryIds'
             ]);
         $product
             ->expects($this->exactly($productsCount))
@@ -338,6 +340,10 @@ public function testAfterImportData()
                 $newSku[1]['entity_id'],
                 $newSku[1]['entity_id']
             );
+        $product
+            ->expects($this->any())
+            ->method('getCategoryIds')
+            ->willReturn([]);
         $product
             ->expects($this->exactly($productsCount))
             ->method('getSku')