MAGETWO-60918: Fatal error on Import/Export page if deleted category ids exists in category path

- Fixed an import/exposrt issue;

Author: Aliaksei Yakimovich2

app/code/Magento/CatalogImportExport/Model/Export/Product.php

@@ -444,8 +444,11 @@ protected function initCategories()
             if ($pathSize > 1) {
                 $path = [];
                 for ($i = 1; $i < $pathSize; $i++) {
-                    $name = $collection->getItemById($structure[$i])->getName();
-                    $path[] = $this->quoteCategoryDelimiter($name);
+                    $childCategory = $collection->getItemById($structure[$i]);
+                    if ($childCategory) {
+                        $name = $childCategory->getName();
+                        $path[] = $this->quoteCategoryDelimiter($name);
+                    }
                 }
                 $this->_rootCategories[$category->getId()] = array_shift($path);
                 if ($pathSize > 2) {
@@ -673,8 +676,8 @@ protected function prepareLinks(array $productIds)
     /**
      * Update data row with information about categories. Return true, if data row was updated
      *
-     * @param array &$dataRow
-     * @param array &$rowCategories
+     * @param array $dataRow
+     * @param array $rowCategories
      * @param int $productId
      * @return bool
      */
@@ -840,6 +843,7 @@ protected function paginateCollection($page, $pageSize)
     public function export()
     {
         //Execution time may be very long
+        // phpcs:ignore Magento2.Functions.DiscouragedFunction
         set_time_limit(0);
 
         $writer = $this->getWriter();
@@ -963,6 +967,7 @@ protected function loadCollection(): array
      * @return array
      * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      * @SuppressWarnings(PHPMD.NPathComplexity)
+     * phpcs:disable Generic.Metrics.NestingLevel
      */
     protected function collectRawData()
     {
@@ -1057,6 +1062,7 @@ protected function collectRawData()
 
         return $data;
     }
+    //phpcs:enable Generic.Metrics.NestingLevel
 
     /**
      * Wrap values with double quotes if "Fields Enclosure" option is enabled