Invalidate product index after change product position in the category

Author: aleksinoleg

app/code/Magento/Catalog/Model/ResourceModel/Category.php

@@ -469,10 +469,6 @@ protected function _saveCategoryProducts($category)
 
         if (!empty($insert) || !empty($delete)) {
             $productIds = array_unique(array_merge(array_keys($insert), array_keys($delete)));
-            $this->_eventManager->dispatch(
-                'catalog_category_change_products',
-                ['category' => $category, 'product_ids' => $productIds]
-            );
 
             $category->setChangedProductIds($productIds);
         }
@@ -484,6 +480,10 @@ protected function _saveCategoryProducts($category)
              * Setting affected products to category for third party engine index refresh
              */
             $productIds = array_keys($insert + $delete + $update);
+            $this->_eventManager->dispatch(
+                'catalog_category_change_products',
+                ['category' => $category, 'product_ids' => $productIds]
+            );
             $category->setAffectedProductIds($productIds);
         }
         return $this;