diff --git a/app/code/Magento/Catalog/Model/Indexer/Product/Price/AbstractAction.php b/app/code/Magento/Catalog/Model/Indexer/Product/Price/AbstractAction.php
index cfa5ec91a2e1b..7aed842713f5d 100644
--- a/app/code/Magento/Catalog/Model/Indexer/Product/Price/AbstractAction.php
+++ b/app/code/Magento/Catalog/Model/Indexer/Product/Price/AbstractAction.php
@@ -336,9 +336,10 @@ protected function _reindexRows($changedIds = [])
         if (!empty($notCompositeIds)) {
             $parentProductsTypes = $this->getParentProductsTypes($notCompositeIds);
             $productsTypes = array_merge_recursive($productsTypes, $parentProductsTypes);
-            $parentProductsIds = array_keys($parentProductsTypes);
-            $compositeIds = $compositeIds + array_combine($parentProductsIds, $parentProductsIds);
-            $changedIds = array_merge($changedIds, $parentProductsIds);
+            foreach ($parentProductsTypes as $parentProductsIds) {
+                $compositeIds = $compositeIds + $parentProductsIds;
+                $changedIds = array_merge($changedIds, $parentProductsIds);
+            }
         }
 
         if (!empty($compositeIds)) {
@@ -370,7 +371,8 @@ protected function _copyRelationIndexData($parentIds, $excludeIds = null)
             ['child_id']
         )->join(
             ['e' => $this->_defaultIndexerResource->getTable('catalog_product_entity')],
-            'e.' . $linkField . ' = parent_id'
+            'e.' . $linkField . ' = parent_id',
+            []
         )->where(
             'e.entity_id IN(?)',
             $parentIds
diff --git a/app/code/Magento/Catalog/Model/Indexer/Product/Price/Action/Full.php b/app/code/Magento/Catalog/Model/Indexer/Product/Price/Action/Full.php
index eb15833a7d0b2..ba04af8ec1f41 100644
--- a/app/code/Magento/Catalog/Model/Indexer/Product/Price/Action/Full.php
+++ b/app/code/Magento/Catalog/Model/Indexer/Product/Price/Action/Full.php
@@ -109,7 +109,7 @@ public function execute($ids = null)
             // Prepare replica table for indexation.
             $this->_defaultIndexerResource->getConnection()->truncateTable($replicaTable);
 
-            /** @var \Magento\Catalog\Model\ResourceModel\Product\Indexer\AbstractIndexer $indexer */
+            /** @var \Magento\Catalog\Model\ResourceModel\Product\Indexer\Price\DefaultPrice $indexer */
             foreach ($this->getTypeIndexers() as $indexer) {
                 $indexer->getTableStrategy()->setUseIdxTable(false);
                 $connection = $indexer->getConnection();
diff --git a/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/DefaultPrice.php b/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/DefaultPrice.php
index 591a26efbf615..285e1781e2f95 100644
--- a/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/DefaultPrice.php
+++ b/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/DefaultPrice.php
@@ -52,6 +52,16 @@ class DefaultPrice extends AbstractIndexer implements PriceInterface
      */
     private $hasEntity = null;
 
+    /**
+     * @var IndexTableStructureFactory
+     */
+    private $indexTableStructureFactory;
+
+    /**
+     * @var PriceModifierInterface[]
+     */
+    private $priceModifiers = [];
+
     /**
      * DefaultPrice constructor.
      *
@@ -61,7 +71,8 @@ class DefaultPrice extends AbstractIndexer implements PriceInterface
      * @param \Magento\Framework\Event\ManagerInterface $eventManager
      * @param \Magento\Framework\Module\Manager $moduleManager
      * @param string|null $connectionName
-     * @param null|\Magento\Indexer\Model\Indexer\StateFactory $stateFactory
+     * @param null|IndexTableStructureFactory $indexTableStructureFactory
+     * @param PriceModifierInterface[] $priceModifiers
      */
     public function __construct(
         \Magento\Framework\Model\ResourceModel\Db\Context $context,
@@ -69,11 +80,25 @@ public function __construct(
         \Magento\Eav\Model\Config $eavConfig,
         \Magento\Framework\Event\ManagerInterface $eventManager,
         \Magento\Framework\Module\Manager $moduleManager,
-        $connectionName = null
+        $connectionName = null,
+        IndexTableStructureFactory $indexTableStructureFactory = null,
+        array $priceModifiers = []
     ) {
         $this->_eventManager = $eventManager;
         $this->moduleManager = $moduleManager;
         parent::__construct($context, $tableStrategy, $eavConfig, $connectionName);
+
+        $this->indexTableStructureFactory = $indexTableStructureFactory ?:
+            \Magento\Framework\App\ObjectManager::getInstance()->get(IndexTableStructureFactory::class);
+        foreach ($priceModifiers as $priceModifier) {
+            if (!($priceModifier instanceof PriceModifierInterface)) {
+                throw new \InvalidArgumentException(
+                    'Argument \'priceModifiers\' must be of the type ' . PriceModifierInterface::class . '[]'
+                );
+            }
+
+            $this->priceModifiers[] = $priceModifier;
+        }
     }
 
     /**
@@ -209,6 +234,8 @@ protected function _getDefaultFinalPriceTable()
      * Prepare final price temporary index table
      *
      * @return $this
+     * @deprecated
+     * @see prepareFinalPriceTable()
      */
     protected function _prepareDefaultFinalPriceTable()
     {
@@ -216,6 +243,32 @@ protected function _prepareDefaultFinalPriceTable()
         return $this;
     }
 
+    /**
+     * Create (if needed), clean and return structure of final price table
+     *
+     * @return IndexTableStructure
+     */
+    private function prepareFinalPriceTable()
+    {
+        $tableName = $this->_getDefaultFinalPriceTable();
+        $this->getConnection()->delete($tableName);
+
+        $finalPriceTable = $this->indexTableStructureFactory->create([
+            'tableName' => $tableName,
+            'entityField' => 'entity_id',
+            'customerGroupField' => 'customer_group_id',
+            'websiteField' => 'website_id',
+            'taxClassField' => 'tax_class_id',
+            'originalPriceField' => 'orig_price',
+            'finalPriceField' => 'price',
+            'minPriceField' => 'min_price',
+            'maxPriceField' => 'max_price',
+            'tierPriceField' => 'tier_price',
+        ]);
+
+        return $finalPriceTable;
+    }
+
     /**
      * Retrieve website current dates table name
      *
@@ -248,11 +301,14 @@ protected function _prepareFinalPriceData($entityIds = null)
      */
     protected function prepareFinalPriceDataForType($entityIds, $type)
     {
-        $this->_prepareDefaultFinalPriceTable();
+        $finalPriceTable = $this->prepareFinalPriceTable();
 
         $select = $this->getSelect($entityIds, $type);
-        $query = $select->insertFromSelect($this->_getDefaultFinalPriceTable(), [], false);
+        $query = $select->insertFromSelect($finalPriceTable->getTableName(), [], false);
         $this->getConnection()->query($query);
+
+        $this->applyDiscountPrices($finalPriceTable);
+
         return $this;
     }
 
@@ -359,7 +415,7 @@ protected function getSelect($entityIds = null, $type = null)
             'e.' . $metadata->getLinkField(),
             'cs.store_id'
         );
-        $currentDate = $connection->getDatePartSql('cwd.website_date');
+        $currentDate = 'cwd.website_date';
 
         $maxUnsignedBigint = '~0';
         $specialFromDate = $connection->getDatePartSql($specialFrom);
@@ -409,6 +465,7 @@ protected function getSelect($entityIds = null, $type = null)
                 'store_field' => new \Zend_Db_Expr('cs.store_id'),
             ]
         );
+
         return $select;
     }
 
@@ -454,6 +511,19 @@ protected function _prepareCustomOptionPriceTable()
         return $this;
     }
 
+    /**
+     * Apply discount prices to final price index table.
+     *
+     * @param IndexTableStructure $finalPriceTable
+     * @return void
+     */
+    private function applyDiscountPrices(IndexTableStructure $finalPriceTable) : void
+    {
+        foreach ($this->priceModifiers as $priceModifier) {
+            $priceModifier->modifyPrice($finalPriceTable);
+        }
+    }
+
     /**
      * Apply custom option minimal and maximal price to temporary final price index table
      *
@@ -463,6 +533,7 @@ protected function _prepareCustomOptionPriceTable()
     protected function _applyCustomOption()
     {
         $connection = $this->getConnection();
+        $finalPriceTable = $this->_getDefaultFinalPriceTable();
         $coaTable = $this->_getCustomOptionAggregateTable();
         $copTable = $this->_getCustomOptionPriceTable();
 
@@ -470,7 +541,7 @@ protected function _applyCustomOption()
         $this->_prepareCustomOptionPriceTable();
 
         $select = $connection->select()->from(
-            ['i' => $this->_getDefaultFinalPriceTable()],
+            ['i' => $finalPriceTable],
             ['entity_id', 'customer_group_id', 'website_id']
         )->join(
             ['cw' => $this->getTable('store_website')],
@@ -537,7 +608,7 @@ protected function _applyCustomOption()
         $connection->query($query);
 
         $select = $connection->select()->from(
-            ['i' => $this->_getDefaultFinalPriceTable()],
+            ['i' => $finalPriceTable],
             ['entity_id', 'customer_group_id', 'website_id']
         )->join(
             ['cw' => $this->getTable('store_website')],
@@ -606,7 +677,7 @@ protected function _applyCustomOption()
         $query = $select->insertFromSelect($copTable);
         $connection->query($query);
 
-        $table = ['i' => $this->_getDefaultFinalPriceTable()];
+        $table = ['i' => $finalPriceTable];
         $select = $connection->select()->join(
             ['io' => $copTable],
             'i.entity_id = io.entity_id AND i.customer_group_id = io.customer_group_id' .
diff --git a/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/IndexTableStructure.php b/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/IndexTableStructure.php
new file mode 100644
index 0000000000000..fb3eef2bf38eb
--- /dev/null
+++ b/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/IndexTableStructure.php
@@ -0,0 +1,181 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Catalog\Model\ResourceModel\Product\Indexer\Price;
+
+/**
+ * Wrapper for structure of price index table.
+ */
+class IndexTableStructure
+{
+    /**
+     * @var string
+     */
+    private $tableName;
+
+    /**
+     * @var string
+     */
+    private $entityField;
+
+    /**
+     * @var string
+     */
+    private $customerGroupField;
+
+    /**
+     * @var string
+     */
+    private $websiteField;
+
+    /**
+     * @var string
+     */
+    private $taxClassField;
+
+    /**
+     * @var string
+     */
+    private $originalPriceField;
+
+    /**
+     * @var string
+     */
+    private $finalPriceField;
+
+    /**
+     * @var string
+     */
+    private $minPriceField;
+
+    /**
+     * @var string
+     */
+    private $maxPriceField;
+
+    /**
+     * @var string
+     */
+    private $tierPriceField;
+
+    /**
+     * @param string $tableName
+     * @param string $entityField
+     * @param string $customerGroupField
+     * @param string $websiteField
+     * @param string $taxClassField
+     * @param string $originalPriceField
+     * @param string $finalPriceField
+     * @param string $minPriceField
+     * @param string $maxPriceField
+     * @param string $tierPriceField
+     * @SuppressWarnings(PHPMD.ExcessiveParameterList)
+     */
+    public function __construct(
+        string $tableName,
+        string $entityField,
+        string $customerGroupField,
+        string $websiteField,
+        string $taxClassField,
+        string $originalPriceField,
+        string $finalPriceField,
+        string $minPriceField,
+        string $maxPriceField,
+        string $tierPriceField
+    ) {
+        $this->tableName = $tableName;
+        $this->entityField = $entityField;
+        $this->customerGroupField = $customerGroupField;
+        $this->websiteField = $websiteField;
+        $this->taxClassField = $taxClassField;
+        $this->originalPriceField = $originalPriceField;
+        $this->finalPriceField = $finalPriceField;
+        $this->minPriceField = $minPriceField;
+        $this->maxPriceField = $maxPriceField;
+        $this->tierPriceField = $tierPriceField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getTableName(): string
+    {
+        return $this->tableName;
+    }
+
+    /**
+     * @return string
+     */
+    public function getEntityField(): string
+    {
+        return $this->entityField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getCustomerGroupField(): string
+    {
+        return $this->customerGroupField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getWebsiteField(): string
+    {
+        return $this->websiteField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getTaxClassField(): string
+    {
+        return $this->taxClassField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getOriginalPriceField(): string
+    {
+        return $this->originalPriceField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getFinalPriceField(): string
+    {
+        return $this->finalPriceField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getMinPriceField(): string
+    {
+        return $this->minPriceField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getMaxPriceField(): string
+    {
+        return $this->maxPriceField;
+    }
+
+    /**
+     * @return string
+     */
+    public function getTierPriceField(): string
+    {
+        return $this->tierPriceField;
+    }
+}
diff --git a/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/PriceModifierInterface.php b/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/PriceModifierInterface.php
new file mode 100644
index 0000000000000..6ecb6aba89933
--- /dev/null
+++ b/app/code/Magento/Catalog/Model/ResourceModel/Product/Indexer/Price/PriceModifierInterface.php
@@ -0,0 +1,23 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Catalog\Model\ResourceModel\Product\Indexer\Price;
+
+/**
+ * Interface for modifying price data in price index table.
+ */
+interface PriceModifierInterface
+{
+    /**
+     * Modify price data.
+     *
+     * @param IndexTableStructure $priceTable
+     * @param array $entityIds
+     * @return void
+     */
+    public function modifyPrice(IndexTableStructure $priceTable, array $entityIds = []) : void;
+}
diff --git a/app/code/Magento/CatalogGraphQl/Model/Layer/CollectionProvider.php b/app/code/Magento/CatalogGraphQl/Model/Layer/CollectionProvider.php
index 1e6fdf0e60e66..86645b0d36fdb 100644
--- a/app/code/Magento/CatalogGraphQl/Model/Layer/CollectionProvider.php
+++ b/app/code/Magento/CatalogGraphQl/Model/Layer/CollectionProvider.php
@@ -29,6 +29,10 @@ class CollectionProvider implements \Magento\Catalog\Model\Layer\ItemCollectionP
      */
     private $collectionProcessor;
 
+    /**
+     * @param \Magento\Framework\Api\SearchCriteria\CollectionProcessorInterface $collectionProcessor
+     * @param \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $collectionFactory
+     */
     public function __construct(
         \Magento\Framework\Api\SearchCriteria\CollectionProcessorInterface $collectionProcessor,
         \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $collectionFactory
diff --git a/app/code/Magento/CatalogImportExport/Model/Import/Product.php b/app/code/Magento/CatalogImportExport/Model/Import/Product.php
index 7d175d524e287..4d42330cd00bf 100644
--- a/app/code/Magento/CatalogImportExport/Model/Import/Product.php
+++ b/app/code/Magento/CatalogImportExport/Model/Import/Product.php
@@ -15,6 +15,7 @@
 use Magento\Framework\App\ObjectManager;
 use Magento\Framework\Exception\LocalizedException;
 use Magento\Framework\Filesystem;
+use Magento\Framework\Intl\DateTimeFactory;
 use Magento\Framework\Model\ResourceModel\Db\ObjectRelationProcessor;
 use Magento\Framework\Model\ResourceModel\Db\TransactionManagerInterface;
 use Magento\Framework\Stdlib\DateTime;
@@ -724,6 +725,11 @@ class Product extends \Magento\ImportExport\Model\Import\Entity\AbstractEntity
      */
     private $mediaProcessor;
 
+    /**
+     * @var DateTimeFactory
+     */
+    private $dateTimeFactory;
+
     /**
      * @param \Magento\Framework\Json\Helper\Data $jsonHelper
      * @param \Magento\ImportExport\Helper\Data $importExportData
@@ -767,7 +773,7 @@ class Product extends \Magento\ImportExport\Model\Import\Entity\AbstractEntity
      * @param ImageTypeProcessor $imageTypeProcessor
      * @param MediaGalleryProcessor $mediaProcessor
      * @param StockItemImporterInterface|null $stockItemImporter
-     *
+     * @param DateTimeFactory $dateTimeFactory
      * @SuppressWarnings(PHPMD.ExcessiveParameterList)
      */
     public function __construct(
@@ -812,7 +818,8 @@ public function __construct(
         CatalogConfig $catalogConfig = null,
         ImageTypeProcessor $imageTypeProcessor = null,
         MediaGalleryProcessor $mediaProcessor = null,
-        StockItemImporterInterface $stockItemImporter = null
+        StockItemImporterInterface $stockItemImporter = null,
+        DateTimeFactory $dateTimeFactory = null
     ) {
         $this->_eventManager = $eventManager;
         $this->stockRegistry = $stockRegistry;
@@ -858,16 +865,14 @@ public function __construct(
             $string,
             $errorAggregator
         );
-        $this->_optionEntity = isset(
-            $data['option_entity']
-        ) ? $data['option_entity'] : $optionFactory->create(
-            ['data' => ['product_entity' => $this]]
-        );
+        $this->_optionEntity = $data['option_entity'] ??
+            $optionFactory->create(['data' => ['product_entity' => $this]]);
         $this->_initAttributeSets()
             ->_initTypeModels()
             ->_initSkus()
             ->initImagesArrayKeys();
         $this->validator->init($this);
+        $this->dateTimeFactory = $dateTimeFactory ?? ObjectManager::getInstance()->get(DateTimeFactory::class);
     }
 
     /**
@@ -2151,40 +2156,8 @@ protected function _saveStockItem()
                 $row = [];
                 $sku = $rowData[self::COL_SKU];
                 if ($this->skuProcessor->getNewSku($sku) !== null) {
-                    $row['product_id'] = $this->skuProcessor->getNewSku($sku)['entity_id'];
+                    $row = $this->formatStockDataForRow($rowData);
                     $productIdsToReindex[] = $row['product_id'];
-
-                    $row['website_id'] = $this->stockConfiguration->getDefaultScopeId();
-                    $row['stock_id'] = $this->stockRegistry->getStock($row['website_id'])->getStockId();
-
-                    $stockItemDo = $this->stockRegistry->getStockItem($row['product_id'], $row['website_id']);
-                    $existStockData = $stockItemDo->getData();
-
-                    $row = array_merge(
-                        $this->defaultStockData,
-                        array_intersect_key($existStockData, $this->defaultStockData),
-                        array_intersect_key($rowData, $this->defaultStockData),
-                        $row
-                    );
-                    $row['sku'] = $sku;
-
-                    if ($this->stockConfiguration->isQty(
-                        $this->skuProcessor->getNewSku($sku)['type_id']
-                    )
-                    ) {
-                        $stockItemDo->setData($row);
-                        $row['is_in_stock'] = $this->stockStateProvider->verifyStock($stockItemDo);
-                        if ($this->stockStateProvider->verifyNotification($stockItemDo)) {
-                            $row['low_stock_date'] = gmdate(
-                                'Y-m-d H:i:s',
-                                (new \DateTime())->getTimestamp()
-                            );
-                        }
-                        $row['stock_status_changed_auto'] =
-                            (int)!$this->stockStateProvider->verifyStock($stockItemDo);
-                    } else {
-                        $row['qty'] = 0;
-                    }
                 }
 
                 if (!isset($stockData[$sku])) {
@@ -2875,4 +2848,44 @@ private function getExistingSku($sku)
     {
         return $this->_oldSku[strtolower($sku)];
     }
+
+    /**
+     * Format row data to DB compatible values.
+     *
+     * @param array $rowData
+     * @return array
+     */
+    private function formatStockDataForRow(array $rowData): array
+    {
+        $sku = $rowData[self::COL_SKU];
+        $row['product_id'] = $this->skuProcessor->getNewSku($sku)['entity_id'];
+        $row['website_id'] = $this->stockConfiguration->getDefaultScopeId();
+        $row['stock_id'] = $this->stockRegistry->getStock($row['website_id'])->getStockId();
+
+        $stockItemDo = $this->stockRegistry->getStockItem($row['product_id'], $row['website_id']);
+        $existStockData = $stockItemDo->getData();
+
+        $row = array_merge(
+            $this->defaultStockData,
+            array_intersect_key($existStockData, $this->defaultStockData),
+            array_intersect_key($rowData, $this->defaultStockData),
+            $row
+        );
+
+        if ($this->stockConfiguration->isQty($this->skuProcessor->getNewSku($sku)['type_id'])) {
+            $stockItemDo->setData($row);
+            $row['is_in_stock'] = isset($row['is_in_stock']) && $stockItemDo->getBackorders()
+                ? $row['is_in_stock']
+                : $this->stockStateProvider->verifyStock($stockItemDo);
+            if ($this->stockStateProvider->verifyNotification($stockItemDo)) {
+                $date = $this->dateTimeFactory->create('now', new \DateTimeZone('UTC'));
+                $row['low_stock_date'] = $date->format(DateTime::DATETIME_PHP_FORMAT);
+            }
+            $row['stock_status_changed_auto'] = (int)!$this->stockStateProvider->verifyStock($stockItemDo);
+        } else {
+            $row['qty'] = 0;
+        }
+
+        return $row;
+    }
 }
diff --git a/app/code/Magento/CatalogImportExport/Model/Import/Product/Option.php b/app/code/Magento/CatalogImportExport/Model/Import/Product/Option.php
index cbaf401f32982..adb660dd118f9 100644
--- a/app/code/Magento/CatalogImportExport/Model/Import/Product/Option.php
+++ b/app/code/Magento/CatalogImportExport/Model/Import/Product/Option.php
@@ -1223,6 +1223,7 @@ protected function _importData()
             $typeTitles = [];
             $parentCount = [];
             $childCount = [];
+            $optionsToRemove = [];
 
             foreach ($bunch as $rowNumber => $rowData) {
                 if (isset($optionId, $valueId) && empty($rowData[PRODUCT::COL_STORE_VIEW_CODE])) {
@@ -1232,14 +1233,18 @@ protected function _importData()
                 $optionId = $nextOptionId;
                 $valueId = $nextValueId;
                 $multiRowData = $this->_getMultiRowFormat($rowData);
-
+                if (!empty($rowData[self::COLUMN_SKU]) && isset($this->_productsSkuToId[$rowData[self::COLUMN_SKU]])) {
+                    $this->_rowProductId = $this->_productsSkuToId[$rowData[self::COLUMN_SKU]];
+                    if (array_key_exists('custom_options', $rowData) && trim($rowData['custom_options']) === '') {
+                        $optionsToRemove[] = $this->_rowProductId;
+                    }
+                }
                 foreach ($multiRowData as $optionData) {
                     $combinedData = array_merge($rowData, $optionData);
 
-                    if (!$this->isRowAllowedToImport($combinedData, $rowNumber)) {
-                        continue;
-                    }
-                    if (!$this->_parseRequiredData($combinedData)) {
+                    if (!$this->isRowAllowedToImport($combinedData, $rowNumber)
+                        || !$this->_parseRequiredData($combinedData)
+                    ) {
                         continue;
                     }
                     $optionData = $this->_collectOptionMainData(
@@ -1266,38 +1271,45 @@ protected function _importData()
                 }
             }
 
-            // Save prepared custom options data !!!
-            if ($this->getBehavior() != \Magento\ImportExport\Model\Import::BEHAVIOR_APPEND) {
-                $this->_deleteEntities(array_keys($products));
-            }
-
-            if ($this->_isReadyForSaving($options, $titles, $typeValues)) {
-                if ($this->getBehavior() == \Magento\ImportExport\Model\Import::BEHAVIOR_APPEND) {
-                    $this->_compareOptionsWithExisting($options, $titles, $prices, $typeValues);
-                    $this->restoreOriginalOptionTypeIds($typeValues, $typePrices, $typeTitles);
-                }
+            $this->removeExistingOptions($products, $optionsToRemove);
 
-                $this->_saveOptions(
-                    $options
-                )->_saveTitles(
-                    $titles
-                )->_savePrices(
-                    $prices
-                )->_saveSpecificTypeValues(
-                    $typeValues
-                )->_saveSpecificTypePrices(
-                    $typePrices
-                )->_saveSpecificTypeTitles(
-                    $typeTitles
-                )->_updateProducts(
-                    $products
-                );
-            }
+            $types = [
+                'values' => $typeValues,
+                'prices' => $typePrices,
+                'titles' => $typeTitles,
+            ];
+            //Save prepared custom options data.
+            $this->savePreparedCustomOptions(
+                $products,
+                $options,
+                $titles,
+                $prices,
+                $types
+            );
         }
 
         return true;
     }
 
+    /**
+     * Remove all existing options if import behaviour is APPEND
+     * in other case remove options for products with empty "custom_options" row only.
+     *
+     * @param array $products
+     * @param array $optionsToRemove
+     *
+     * @return void
+     */
+    private function removeExistingOptions(array $products, array $optionsToRemove): void
+    {
+        if ($this->getBehavior() != \Magento\ImportExport\Model\Import::BEHAVIOR_APPEND) {
+            $this->_deleteEntities(array_keys($products));
+        } elseif (!empty($optionsToRemove)) {
+            // Remove options for products with empty "custom_options" row
+            $this->_deleteEntities($optionsToRemove);
+        }
+    }
+
     /**
      * Load data of existed products
      *
@@ -1537,9 +1549,7 @@ private function getExistingOptionTypeId($optionId, $storeId, $optionTypeTitle)
      */
     protected function _parseRequiredData(array $rowData)
     {
-        if ($rowData[self::COLUMN_SKU] != '' && isset($this->_productsSkuToId[$rowData[self::COLUMN_SKU]])) {
-            $this->_rowProductId = $this->_productsSkuToId[$rowData[self::COLUMN_SKU]];
-        } elseif (!isset($this->_rowProductId)) {
+        if ($this->_rowProductId === null) {
             return false;
         }
 
@@ -1991,4 +2001,38 @@ private function getProductIdentifierField()
         }
         return $this->productEntityIdentifierField;
     }
+
+    /**
+     * Save prepared custom options.
+     *
+     * @param array $products
+     * @param array $options
+     * @param array $titles
+     * @param array $prices
+     * @param array $types
+     *
+     * @return void
+     */
+    private function savePreparedCustomOptions(
+        array $products,
+        array $options,
+        array $titles,
+        array $prices,
+        array $types
+    ): void {
+        if ($this->_isReadyForSaving($options, $titles, $types['values'])) {
+            if ($this->getBehavior() == \Magento\ImportExport\Model\Import::BEHAVIOR_APPEND) {
+                $this->_compareOptionsWithExisting($options, $titles, $prices, $types['values']);
+                $this->restoreOriginalOptionTypeIds($types['values'], $types['prices'], $types['titles']);
+            }
+
+            $this->_saveOptions($options)
+                ->_saveTitles($titles)
+                ->_savePrices($prices)
+                ->_saveSpecificTypeValues($types['values'])
+                ->_saveSpecificTypePrices($types['prices'])
+                ->_saveSpecificTypeTitles($types['titles'])
+                ->_updateProducts($products);
+        }
+    }
 }
diff --git a/app/code/Magento/CatalogRule/Model/Indexer/ProductPriceIndexModifier.php b/app/code/Magento/CatalogRule/Model/Indexer/ProductPriceIndexModifier.php
new file mode 100644
index 0000000000000..a60b05dc7c9bc
--- /dev/null
+++ b/app/code/Magento/CatalogRule/Model/Indexer/ProductPriceIndexModifier.php
@@ -0,0 +1,75 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogRule\Model\Indexer;
+
+use Magento\Catalog\Model\ResourceModel\Product\Indexer\Price\PriceModifierInterface;
+use Magento\Catalog\Model\ResourceModel\Product\Indexer\Price\IndexTableStructure;
+use Magento\CatalogRule\Model\ResourceModel\Rule\Product\Price;
+
+/**
+ * Class for adding catalog rule prices to price index table.
+ */
+class ProductPriceIndexModifier implements PriceModifierInterface
+{
+    /**
+     * @var Price
+     */
+    private $priceResourceModel;
+
+    /**
+     * @param Price $priceResourceModel
+     */
+    public function __construct(Price $priceResourceModel)
+    {
+        $this->priceResourceModel = $priceResourceModel;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function modifyPrice(IndexTableStructure $priceTable, array $entityIds = []) : void
+    {
+        $connection = $this->priceResourceModel->getConnection();
+        $select = $connection->select();
+
+        $select->join(
+            ['cpiw' => $this->priceResourceModel->getTable('catalog_product_index_website')],
+            'cpiw.website_id = i.' . $priceTable->getWebsiteField(),
+            []
+        );
+        $select->join(
+            ['cpp' => $this->priceResourceModel->getMainTable()],
+            'cpp.product_id = i.' . $priceTable->getEntityField()
+            . ' AND cpp.customer_group_id = i.' . $priceTable->getCustomerGroupField()
+            . ' AND cpp.website_id = i.' . $priceTable->getWebsiteField()
+            . ' AND cpp.rule_date = cpiw.website_date',
+            []
+        );
+        if ($entityIds) {
+            $select->where('i.entity_id IN (?)', $entityIds);
+        }
+
+        $finalPrice = $priceTable->getFinalPriceField();
+        $finalPriceExpr = $select->getConnection()->getLeastSql([
+            $priceTable->getFinalPriceField(),
+            $select->getConnection()->getIfNullSql('cpp.rule_price', 'i.' . $finalPrice),
+        ]);
+        $minPrice = $priceTable->getMinPriceField();
+        $minPriceExpr = $select->getConnection()->getLeastSql([
+            $priceTable->getMinPriceField(),
+            $select->getConnection()->getIfNullSql('cpp.rule_price', 'i.' . $minPrice),
+        ]);
+        $select->columns([
+            $finalPrice => $finalPriceExpr,
+            $minPrice => $minPriceExpr,
+        ]);
+
+        $query = $connection->updateFromSelect($select, ['i' => $priceTable->getTableName()]);
+        $connection->query($query);
+    }
+}
diff --git a/app/code/Magento/CatalogRule/Model/Rule.php b/app/code/Magento/CatalogRule/Model/Rule.php
index 7696569cb26da..d927d6f4d0c82 100644
--- a/app/code/Magento/CatalogRule/Model/Rule.php
+++ b/app/code/Magento/CatalogRule/Model/Rule.php
@@ -606,7 +606,10 @@ public function afterSave()
      */
     public function reindex()
     {
-        $this->_ruleProductProcessor->reindexList($this->_productIds);
+        $productIds = $this->_productIds ? array_keys(array_filter($this->_productIds, function (array $data) {
+            return array_filter($data);
+        })) : [];
+        $this->_ruleProductProcessor->reindexList($productIds);
     }
 
     /**
diff --git a/app/code/Magento/CatalogRule/etc/di.xml b/app/code/Magento/CatalogRule/etc/di.xml
index 40893592c3d0f..8ed88dd4f3fdb 100644
--- a/app/code/Magento/CatalogRule/etc/di.xml
+++ b/app/code/Magento/CatalogRule/etc/di.xml
@@ -150,4 +150,11 @@
         </arguments>
     </type>
     <preference for="Magento\CatalogRule\Model\Indexer\IndexerTableSwapperInterface" type="Magento\CatalogRule\Model\Indexer\IndexerTableSwapper" />
+    <type name="Magento\Catalog\Model\ResourceModel\Product\Indexer\Price\PriceInterface">
+        <arguments>
+            <argument name="priceModifiers" xsi:type="array">
+                <item name="catalogRulePriceModifier" xsi:type="object">Magento\CatalogRule\Model\Indexer\ProductPriceIndexModifier</item>
+            </argument>
+        </arguments>
+    </type>
 </config>
diff --git a/app/code/Magento/CatalogRule/etc/indexer.xml b/app/code/Magento/CatalogRule/etc/indexer.xml
index 08ed456457bfe..e648ea567631c 100644
--- a/app/code/Magento/CatalogRule/etc/indexer.xml
+++ b/app/code/Magento/CatalogRule/etc/indexer.xml
@@ -14,4 +14,9 @@
         <title translate="true">Catalog Product Rule</title>
         <description translate="true">Indexed product/rule association</description>
     </indexer>
+    <indexer id="catalog_product_price">
+        <dependencies>
+            <indexer id="catalogrule_rule" />
+        </dependencies>
+    </indexer>
 </config>
diff --git a/app/code/Magento/CatalogUrlRewrite/Plugin/Store/Block/Switcher.php b/app/code/Magento/CatalogUrlRewrite/Plugin/Store/Block/Switcher.php
new file mode 100644
index 0000000000000..44213c007551c
--- /dev/null
+++ b/app/code/Magento/CatalogUrlRewrite/Plugin/Store/Block/Switcher.php
@@ -0,0 +1,86 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogUrlRewrite\Plugin\Store\Block;
+
+use Magento\Framework\Data\Helper\PostHelper;
+use Magento\Store\Api\StoreResolverInterface;
+use Magento\Store\Model\Store;
+use Magento\UrlRewrite\Model\UrlFinderInterface;
+use Magento\UrlRewrite\Service\V1\Data\UrlRewrite;
+use Magento\Framework\App\Request\Http as HttpRequest;
+
+/**
+ * Plugin makes connection between Store and UrlRewrite modules
+ * because Magento\Store\Block\Switcher should not know about UrlRewrite module functionality.
+ */
+class Switcher
+{
+    /**
+     * @var PostHelper
+     */
+    private $postHelper;
+
+    /**
+     * @var UrlFinderInterface
+     */
+    private $urlFinder;
+
+    /**
+     * @var HttpRequest
+     */
+    private $request;
+
+    /**
+     * @param PostHelper $postHelper
+     * @param UrlFinderInterface $urlFinder
+     * @param HttpRequest $request
+     */
+    public function __construct(
+        PostHelper $postHelper,
+        UrlFinderInterface $urlFinder,
+        HttpRequest $request
+    ) {
+        $this->postHelper = $postHelper;
+        $this->urlFinder = $urlFinder;
+        $this->request = $request;
+    }
+
+    /**
+     * @param \Magento\Store\Block\Switcher $subject
+     * @param string $result
+     * @param Store $store
+     * @param array $data
+     * @return string
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function afterGetTargetStorePostData(
+        \Magento\Store\Block\Switcher $subject,
+        string $result,
+        Store $store,
+        array $data = []
+    ): string {
+        $data[StoreResolverInterface::PARAM_NAME] = $store->getCode();
+        $currentUrl = $store->getCurrentUrl(true);
+        $baseUrl = $store->getBaseUrl();
+        $urlPath = parse_url($currentUrl, PHP_URL_PATH);
+        $urlToSwitch = $currentUrl;
+
+        //check only catalog pages
+        if ($this->request->getFrontName() === 'catalog') {
+            $currentRewrite = $this->urlFinder->findOneByData([
+                UrlRewrite::REQUEST_PATH => ltrim($urlPath, '/'),
+                UrlRewrite::STORE_ID => $store->getId(),
+            ]);
+            if (null === $currentRewrite) {
+                $urlToSwitch = $baseUrl;
+            }
+        }
+
+        return $this->postHelper->getPostData($urlToSwitch, $data);
+    }
+}
diff --git a/app/code/Magento/CatalogUrlRewrite/etc/frontend/di.xml b/app/code/Magento/CatalogUrlRewrite/etc/frontend/di.xml
new file mode 100644
index 0000000000000..3a9122b2f748d
--- /dev/null
+++ b/app/code/Magento/CatalogUrlRewrite/etc/frontend/di.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
+    <type name="\Magento\Store\Block\Switcher">
+        <plugin name="store_switcher_plugin" type="Magento\CatalogUrlRewrite\Plugin\Store\Block\Switcher"/>
+    </type>
+</config>
diff --git a/app/code/Magento/ConfigurableProduct/Model/ResourceModel/Product/Indexer/Price/Configurable.php b/app/code/Magento/ConfigurableProduct/Model/ResourceModel/Product/Indexer/Price/Configurable.php
index 326310cc3c802..087931ebe5dcc 100644
--- a/app/code/Magento/ConfigurableProduct/Model/ResourceModel/Product/Indexer/Price/Configurable.php
+++ b/app/code/Magento/ConfigurableProduct/Model/ResourceModel/Product/Indexer/Price/Configurable.php
@@ -1,7 +1,5 @@
 <?php
 /**
- * Configurable Products Price Indexer Resource model
- *
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
@@ -11,41 +9,10 @@
 use Magento\Store\Api\StoreResolverInterface;
 
 /**
- * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ * Configurable Products Price Indexer Resource model
  */
 class Configurable extends \Magento\Catalog\Model\ResourceModel\Product\Indexer\Price\DefaultPrice
 {
-    /**
-     * @var StoreResolverInterface
-     */
-    private $storeResolver;
-
-    /**
-     * Class constructor
-     *
-     * @param \Magento\Framework\Model\ResourceModel\Db\Context $context
-     * @param \Magento\Framework\Indexer\Table\StrategyInterface $tableStrategy
-     * @param \Magento\Eav\Model\Config $eavConfig
-     * @param \Magento\Framework\Event\ManagerInterface $eventManager
-     * @param \Magento\Framework\Module\Manager $moduleManager
-     * @param string|null $connectionName
-     * @param StoreResolverInterface|null $storeResolver
-     */
-    public function __construct(
-        \Magento\Framework\Model\ResourceModel\Db\Context $context,
-        \Magento\Framework\Indexer\Table\StrategyInterface $tableStrategy,
-        \Magento\Eav\Model\Config $eavConfig,
-        \Magento\Framework\Event\ManagerInterface $eventManager,
-        \Magento\Framework\Module\Manager $moduleManager,
-        $connectionName = null,
-        StoreResolverInterface $storeResolver = null
-    ) {
-        parent::__construct($context, $tableStrategy, $eavConfig, $eventManager, $moduleManager, $connectionName);
-        $this->storeResolver = $storeResolver ?: \Magento\Framework\App\ObjectManager::getInstance()->get(
-            StoreResolverInterface::class
-        );
-    }
-
     /**
      * @param null|int|array $entityIds
      * @return \Magento\ConfigurableProduct\Model\ResourceModel\Product\Indexer\Price\Configurable
@@ -58,6 +25,7 @@ protected function reindex($entityIds = null)
             $this->_applyConfigurableOption($entityIds);
             $this->_movePriceDataToIndexTable($entityIds);
         }
+
         return $this;
     }
 
@@ -109,67 +77,49 @@ protected function _prepareConfigurableOptionPriceTable()
      *
      * @param array|null $entityIds
      * @return \Magento\ConfigurableProduct\Model\ResourceModel\Product\Indexer\Price\Configurable
-     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
      */
     protected function _applyConfigurableOption($entityIds = null)
     {
         $metadata = $this->getMetadataPool()->getMetadata(ProductInterface::class);
         $connection = $this->getConnection();
-        $coaTable = $this->_getConfigurableOptionAggregateTable();
         $copTable = $this->_getConfigurableOptionPriceTable();
+        $finalPriceTable = $this->_getDefaultFinalPriceTable();
         $linkField = $metadata->getLinkField();
 
-        $this->_prepareConfigurableOptionAggregateTable();
         $this->_prepareConfigurableOptionPriceTable();
 
-        $subSelect = $this->getSelect();
-        $subSelect->join(
+        $select = $connection->select()->from(
+            ['i' => $this->getIdxTable()],
+            []
+        )->join(
             ['l' => $this->getTable('catalog_product_super_link')],
-            'l.product_id = e.entity_id',
+            'l.product_id = i.entity_id',
             []
         )->join(
             ['le' => $this->getTable('catalog_product_entity')],
             'le.' . $linkField . ' = l.parent_id',
-            ['parent_id' => 'entity_id']
-        );
-
-        if ($entityIds !== null) {
-            $subSelect->where('le.entity_id IN (?)', $entityIds);
-        }
-
-        $select = $connection->select();
-        $select
-            ->from(['sub' => new \Zend_Db_Expr('(' . (string)$subSelect . ')')], '')
-            ->columns([
-                'sub.parent_id',
-                'sub.entity_id',
-                'sub.customer_group_id',
-                'sub.website_id',
-                'sub.price',
-                'sub.tier_price'
-            ]);
-
-        $query = $select->insertFromSelect($coaTable);
-        $connection->query($query);
-
-        $select = $connection->select()->from(
-            [$coaTable],
+            []
+        )->columns(
             [
-                'parent_id',
+                'le.entity_id',
                 'customer_group_id',
                 'website_id',
-                'MIN(price)',
-                'MAX(price)',
+                'MIN(final_price)',
+                'MAX(final_price)',
                 'MIN(tier_price)',
+
             ]
         )->group(
-            ['parent_id', 'customer_group_id', 'website_id']
+            ['le.entity_id', 'customer_group_id', 'website_id']
         );
+        if ($entityIds !== null) {
+            $select->where('le.entity_id IN (?)', $entityIds);
+        }
 
         $query = $select->insertFromSelect($copTable);
         $connection->query($query);
 
-        $table = ['i' => $this->_getDefaultFinalPriceTable()];
+        $table = ['i' => $finalPriceTable];
         $select = $connection->select()->join(
             ['io' => $copTable],
             'i.entity_id = io.entity_id AND i.customer_group_id = io.customer_group_id' .
@@ -188,7 +138,6 @@ protected function _applyConfigurableOption($entityIds = null)
         $query = $select->crossUpdateFromSelect($table);
         $connection->query($query);
 
-        $connection->delete($coaTable);
         $connection->delete($copTable);
 
         return $this;
diff --git a/app/code/Magento/Downloadable/Model/ResourceModel/Indexer/Price.php b/app/code/Magento/Downloadable/Model/ResourceModel/Indexer/Price.php
index dd83c28b43dff..855fac5041b21 100644
--- a/app/code/Magento/Downloadable/Model/ResourceModel/Indexer/Price.php
+++ b/app/code/Magento/Downloadable/Model/ResourceModel/Indexer/Price.php
@@ -62,6 +62,7 @@ protected function _applyDownloadableLink()
     {
         $connection = $this->getConnection();
         $table = $this->_getDownloadableLinkPriceTable();
+        $finalPriceTable = $this->_getDefaultFinalPriceTable();
 
         $this->_prepareDownloadableLinkPriceTable();
 
@@ -71,7 +72,7 @@ protected function _applyDownloadableLink()
         $ifPrice = $connection->getIfNullSql('dlpw.price_id', 'dlpd.price');
 
         $select = $connection->select()->from(
-            ['i' => $this->_getDefaultFinalPriceTable()],
+            ['i' => $finalPriceTable],
             ['entity_id', 'customer_group_id', 'website_id']
         )->join(
             ['dl' => $dlType->getBackend()->getTable()],
@@ -119,7 +120,7 @@ protected function _applyDownloadableLink()
             ]
         );
 
-        $query = $select->crossUpdateFromSelect(['i' => $this->_getDefaultFinalPriceTable()]);
+        $query = $select->crossUpdateFromSelect(['i' => $finalPriceTable]);
         $connection->query($query);
 
         $connection->delete($table);
diff --git a/app/code/Magento/NewRelicReporting/Model/Observer/ReportApplicationHandledExceptionToNewRelic.php b/app/code/Magento/NewRelicReporting/Model/Observer/ReportApplicationHandledExceptionToNewRelic.php
index 724a488570207..ce7e95950c937 100644
--- a/app/code/Magento/NewRelicReporting/Model/Observer/ReportApplicationHandledExceptionToNewRelic.php
+++ b/app/code/Magento/NewRelicReporting/Model/Observer/ReportApplicationHandledExceptionToNewRelic.php
@@ -37,6 +37,9 @@ public function __construct(
         $this->newRelicWrapper = $newRelicWrapper;
     }
 
+    /**
+     * @param Observer $observer
+     */
     public function execute(Observer $observer)
     {
         if ($this->config->isNewRelicEnabled()) {
diff --git a/app/code/Magento/Paypal/etc/adminhtml/system.xml b/app/code/Magento/Paypal/etc/adminhtml/system.xml
index 1c8da8127f8fe..c1ff4c9b1c6ca 100644
--- a/app/code/Magento/Paypal/etc/adminhtml/system.xml
+++ b/app/code/Magento/Paypal/etc/adminhtml/system.xml
@@ -32,6 +32,7 @@
             </group>
             <group id="other_payment_methods" translate="label" sortOrder="4" showInDefault="1" showInWebsite="1" showInStore="1">
                 <label>Other Payment Methods:</label>
+                <attribute type="expanded">1</attribute>
                 <fieldset_css>paypal-top-section payments-other-header</fieldset_css>
                 <frontend_model>\Magento\Config\Block\System\Config\Form\Fieldset</frontend_model>
             </group>
diff --git a/app/code/Magento/Sales/Model/ResourceModel/EntityAbstract.php b/app/code/Magento/Sales/Model/ResourceModel/EntityAbstract.php
index 1b781890e0f7f..80612277e68d5 100644
--- a/app/code/Magento/Sales/Model/ResourceModel/EntityAbstract.php
+++ b/app/code/Magento/Sales/Model/ResourceModel/EntityAbstract.php
@@ -123,10 +123,15 @@ protected function _beforeSave(\Magento\Framework\Model\AbstractModel $object)
     {
         /** @var \Magento\Sales\Model\AbstractModel $object */
         if ($object instanceof EntityInterface && $object->getIncrementId() == null) {
+            $store = $object->getStore();
+            $storeId = $store->getId();
+            if ($storeId === null) {
+                $storeId = $store->getGroup()->getDefaultStoreId();
+            }
             $object->setIncrementId(
                 $this->sequenceManager->getSequence(
                     $object->getEntityType(),
-                    $object->getStore()->getGroup()->getDefaultStoreId()
+                    $storeId
                 )->getNextValue()
             );
         }
diff --git a/app/code/Magento/Sales/Observer/Backend/SubtractQtyFromQuotesObserver.php b/app/code/Magento/Sales/Observer/Backend/SubtractQtyFromQuotesObserver.php
index 775a7dab95cfe..cd8c705750d6c 100644
--- a/app/code/Magento/Sales/Observer/Backend/SubtractQtyFromQuotesObserver.php
+++ b/app/code/Magento/Sales/Observer/Backend/SubtractQtyFromQuotesObserver.php
@@ -31,6 +31,6 @@ public function __construct(\Magento\Quote\Model\ResourceModel\Quote $quote)
     public function execute(\Magento\Framework\Event\Observer $observer)
     {
         $product = $observer->getEvent()->getProduct();
-        $this->_quote->substractProductFromQuotes($product);
+        $this->_quote->subtractProductFromQuotes($product);
     }
 }
diff --git a/app/code/Magento/Sales/Setup/SalesSetup.php b/app/code/Magento/Sales/Setup/SalesSetup.php
index bfc05c549ddb3..4be2b38b074e7 100644
--- a/app/code/Magento/Sales/Setup/SalesSetup.php
+++ b/app/code/Magento/Sales/Setup/SalesSetup.php
@@ -303,6 +303,9 @@ public function getEncryptor()
         return $this->encryptor;
     }
 
+    /**
+     * @return \Magento\Framework\DB\Adapter\AdapterInterface
+     */
     public function getConnection()
     {
         return $this->getSetup()->getConnection(self::$connectionName);
diff --git a/app/code/Magento/Sales/Test/Unit/Observer/Backend/SubtractQtyFromQuotesObserverTest.php b/app/code/Magento/Sales/Test/Unit/Observer/Backend/SubtractQtyFromQuotesObserverTest.php
index a6a828c888fc0..949121eadee44 100644
--- a/app/code/Magento/Sales/Test/Unit/Observer/Backend/SubtractQtyFromQuotesObserverTest.php
+++ b/app/code/Magento/Sales/Test/Unit/Observer/Backend/SubtractQtyFromQuotesObserverTest.php
@@ -48,7 +48,7 @@ public function testSubtractQtyFromQuotes()
             ['getId', 'getStatus', '__wakeup']
         );
         $this->_eventMock->expects($this->once())->method('getProduct')->will($this->returnValue($productMock));
-        $this->_quoteMock->expects($this->once())->method('substractProductFromQuotes')->with($productMock);
+        $this->_quoteMock->expects($this->once())->method('subtractProductFromQuotes')->with($productMock);
         $this->_model->execute($this->_observerMock);
     }
 }
diff --git a/app/code/Magento/Tax/Model/Config.php b/app/code/Magento/Tax/Model/Config.php
index b30e5afb85142..09212ce90bf58 100644
--- a/app/code/Magento/Tax/Model/Config.php
+++ b/app/code/Magento/Tax/Model/Config.php
@@ -832,12 +832,12 @@ public function getInfoUrl($store = null)
      * If it necessary will be returned conversion type (minus or plus)
      *
      * @param null|int|string|Store $store
-     * @return bool
+     * @return bool|int
      * @SuppressWarnings(PHPMD.CyclomaticComplexity)
      */
     public function needPriceConversion($store = null)
     {
-        $res = false;
+        $res = 0;
         $priceIncludesTax = $this->priceIncludesTax($store) || $this->getNeedUseShippingExcludeTax();
         if ($priceIncludesTax) {
             switch ($this->getPriceDisplayType($store)) {
@@ -845,7 +845,7 @@ public function needPriceConversion($store = null)
                 case self::DISPLAY_TYPE_BOTH:
                     return self::PRICE_CONVERSION_MINUS;
                 case self::DISPLAY_TYPE_INCLUDING_TAX:
-                    $res = true;
+                    $res = false;
                     break;
                 default:
                     break;
diff --git a/app/code/Magento/Tax/Model/ResourceModel/Calculation/Rule.php b/app/code/Magento/Tax/Model/ResourceModel/Calculation/Rule.php
index e509f477bcd8d..91fd0f4dcffb3 100644
--- a/app/code/Magento/Tax/Model/ResourceModel/Calculation/Rule.php
+++ b/app/code/Magento/Tax/Model/ResourceModel/Calculation/Rule.php
@@ -6,7 +6,7 @@
 namespace Magento\Tax\Model\ResourceModel\Calculation;
 
 /**
- * Tax rate resource model
+ * Tax rule resource model
  *
  * @author      Magento Core Team <core@magentocommerce.com>
  */
diff --git a/app/design/frontend/Magento/luma/Magento_Checkout/web/css/source/module/checkout/_payments.less b/app/design/frontend/Magento/luma/Magento_Checkout/web/css/source/module/checkout/_payments.less
index 3136056d9426d..c7fa7a62fd68e 100644
--- a/app/design/frontend/Magento/luma/Magento_Checkout/web/css/source/module/checkout/_payments.less
+++ b/app/design/frontend/Magento/luma/Magento_Checkout/web/css/source/module/checkout/_payments.less
@@ -46,6 +46,11 @@
                     .lib-css(border-top, @checkout-payment-method-title__border);
                 }
             }
+            form {
+                &.form-purchase-order {
+                    margin-bottom: 15px;
+                }
+            }
         }
 
         .payment-method-content {
diff --git a/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Page/AdminConfigPaymentMethodsPage.xml b/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Page/AdminConfigPaymentMethodsPage.xml
new file mode 100644
index 0000000000000..9fa1a71e3441b
--- /dev/null
+++ b/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Page/AdminConfigPaymentMethodsPage.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+ /**
+  * Copyright © Magento, Inc. All rights reserved.
+  * See COPYING.txt for license details.
+  */
+-->
+<pages xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../../vendor/magento/magento2-functional-testing-framework/src/Magento/FunctionalTestingFramework/Page/etc/PageObject.xsd">
+    <page name="AdminConfigPaymentMethodsPage" url="admin/system_config/edit/section/payment/" area="admin" module="Magento_Config">
+        <section name="OtherPaymentsConfigSection"/>
+    </page>
+</pages>
diff --git a/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Section/OtherPaymentsConfigSection.xml b/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Section/OtherPaymentsConfigSection.xml
new file mode 100644
index 0000000000000..024c1317dba2f
--- /dev/null
+++ b/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Section/OtherPaymentsConfigSection.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ /**
+  * Copyright © Magento, Inc. All rights reserved.
+  * See COPYING.txt for license details.
+  */
+-->
+
+<sections xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="../../../../../../vendor/magento/magento2-functional-testing-framework/src/Magento/FunctionalTestingFramework/Page/etc/SectionObject.xsd">
+    <section name="OtherPaymentsConfigSection">
+        <element name="expandedTab" type="button" selector="#payment_us_other_payment_methods-head.open"/>
+    </section>
+</sections>
diff --git a/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Test/AdminConfigPaymentsSectionState.xml b/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Test/AdminConfigPaymentsSectionState.xml
new file mode 100644
index 0000000000000..90c8dd5896198
--- /dev/null
+++ b/dev/tests/acceptance/tests/functional/Magento/FunctionalTest/Paypal/Test/AdminConfigPaymentsSectionState.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ /**
+  * Copyright © Magento, Inc. All rights reserved.
+  * See COPYING.txt for license details.
+  */
+-->
+
+<tests xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="../../../../../../vendor/magento/magento2-functional-testing-framework/src/Magento/FunctionalTestingFramework/Test/etc/testSchema.xsd">
+    <test name="AdminConfigPaymentsSectionState">
+        <annotations>
+            <description value="Other Payment Methods section in Admin expanded by default"/>
+            <severity value="AVERAGE"/>
+            <testCaseId value="MAGETWO-92043"/>
+        </annotations>
+        <after>
+            <amOnPage url="admin/admin/auth/logout/" stepKey="amOnLogoutPage"/>
+        </after>
+
+        <actionGroup ref="LoginAsAdmin" stepKey="loginAsAdmin1"/>
+        <amOnPage url="{{AdminConfigPaymentMethodsPage.url}}" stepKey="navigateToConfigurationPage"/>
+        <waitForPageLoad stepKey="waitForPageLoad1"/>
+        <seeElement selector="{{OtherPaymentsConfigSection.expandedTab}}" stepKey="seeSectionExpanded"/>
+    </test>
+</tests>
diff --git a/dev/tests/api-functional/framework/Magento/TestFramework/Annotation/ApiDataFixture.php b/dev/tests/api-functional/framework/Magento/TestFramework/Annotation/ApiDataFixture.php
index bd83cdcaf3fb1..88ac682f6b282 100644
--- a/dev/tests/api-functional/framework/Magento/TestFramework/Annotation/ApiDataFixture.php
+++ b/dev/tests/api-functional/framework/Magento/TestFramework/Annotation/ApiDataFixture.php
@@ -100,6 +100,7 @@ protected function _getFixtures($scope, \PHPUnit\Framework\TestCase $test)
      * Execute single fixture script
      *
      * @param string|array $fixture
+     * @throws \Throwable
      */
     protected function _applyOneFixture($fixture)
     {
@@ -110,9 +111,13 @@ protected function _applyOneFixture($fixture)
                 require $fixture;
             }
         } catch (\Exception $e) {
-            echo 'Exception occurred when running the '
-            . (is_array($fixture) || is_scalar($fixture) ? json_encode($fixture) : 'callback')
-            . ' fixture: ', PHP_EOL, $e;
+            throw new \Exception(
+                sprintf(
+                    "Exception occurred when running the %s fixture: \n%s",
+                    (\is_array($fixture) || is_scalar($fixture) ? json_encode($fixture) : 'callback'),
+                    $e->getMessage()
+                )
+            );
         }
         $this->_appliedFixtures[] = $fixture;
     }
diff --git a/dev/tests/integration/testsuite/Magento/Catalog/Block/Adminhtml/Product/Edit/JsTest.php b/dev/tests/integration/testsuite/Magento/Catalog/Block/Adminhtml/Product/Edit/JsTest.php
index 79989c24ea96d..f2043b3c5fff1 100644
--- a/dev/tests/integration/testsuite/Magento/Catalog/Block/Adminhtml/Product/Edit/JsTest.php
+++ b/dev/tests/integration/testsuite/Magento/Catalog/Block/Adminhtml/Product/Edit/JsTest.php
@@ -29,23 +29,18 @@ public function testGetAllRatesByProductClassJson()
         /** @var \Magento\Catalog\Block\Adminhtml\Product\Edit\Js $block */
         $block = $objectManager->create(\Magento\Catalog\Block\Adminhtml\Product\Edit\Js::class);
         $jsonResult = $block->getAllRatesByProductClassJson();
-        $decodedResult = json_decode($jsonResult);
-        $this->assertNotEmpty($decodedResult, 'Resulting JSON is invalid.');
-        $taxClassesArray = (array)$decodedResult;
+        $this->assertJson($jsonResult, 'Resulting JSON is invalid.');
+        $decodedResult = json_decode($jsonResult, true);
+        $this->assertNotNull($decodedResult, 'Cannot decode resulting JSON.');
         $noneTaxClass = 0;
         $defaultProductTaxClass = 2;
         $expectedProductTaxClasses = array_unique(
             array_merge($fixtureTaxRule->getProductTaxClasses(), [$defaultProductTaxClass, $noneTaxClass])
         );
-        $this->assertCount(
-            count($expectedProductTaxClasses),
-            $taxClassesArray,
-            'Invalid quantity of rates for tax classes.'
-        );
         foreach ($expectedProductTaxClasses as $taxClassId) {
             $this->assertArrayHasKey(
                 "value_{$taxClassId}",
-                $taxClassesArray,
+                $decodedResult,
                 "Rates for tax class with ID '{$taxClassId}' is missing."
             );
         }
diff --git a/dev/tests/integration/testsuite/Magento/Catalog/Model/ProductTest.php b/dev/tests/integration/testsuite/Magento/Catalog/Model/ProductTest.php
index 8b33c962cc809..b00090850e09b 100644
--- a/dev/tests/integration/testsuite/Magento/Catalog/Model/ProductTest.php
+++ b/dev/tests/integration/testsuite/Magento/Catalog/Model/ProductTest.php
@@ -4,6 +4,8 @@
  * See COPYING.txt for license details.
  */
 
+declare(strict_types=1);
+
 namespace Magento\Catalog\Model;
 
 use Magento\Framework\App\Filesystem\DirectoryList;
@@ -552,4 +554,47 @@ public function testGetOptions()
             }
         }
     }
+
+    /**
+     * Check stock status changing if backorders functionality enabled.
+     *
+     * @magentoDataFixture Magento/Catalog/_files/product_simple_out_of_stock.php
+     * @dataProvider productWithBackordersDataProvider
+     * @param int $qty
+     * @param int $stockStatus
+     * @param bool $expectedStockStatus
+     *
+     * @return void
+     */
+    public function testSaveWithBackordersEnabled(int $qty, int $stockStatus, bool $expectedStockStatus): void
+    {
+        $product = $this->productRepository->get('simple-out-of-stock', true, null, true);
+        $stockItem = $product->getExtensionAttributes()->getStockItem();
+        $this->assertEquals(false, $stockItem->getIsInStock());
+        $stockData = [
+            'backorders' => 1,
+            'qty' => $qty,
+            'is_in_stock' => $stockStatus,
+        ];
+        $product->setStockData($stockData);
+        $product->save();
+        $stockItem = $product->getExtensionAttributes()->getStockItem();
+
+        $this->assertEquals($expectedStockStatus, $stockItem->getIsInStock());
+    }
+
+    /**
+     * DataProvider for the testSaveWithBackordersEnabled()
+     * @return array
+     */
+    public function productWithBackordersDataProvider(): array
+    {
+        return [
+            [0, 0, false],
+            [0, 1, true],
+            [-1, 0, false],
+            [-1, 1, true],
+            [1, 1, true],
+        ];
+    }
 }
diff --git a/dev/tests/integration/testsuite/Magento/Catalog/_files/product_simple_out_of_stock.php b/dev/tests/integration/testsuite/Magento/Catalog/_files/product_simple_out_of_stock.php
new file mode 100644
index 0000000000000..6630c0d69e34f
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/Catalog/_files/product_simple_out_of_stock.php
@@ -0,0 +1,53 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+\Magento\TestFramework\Helper\Bootstrap::getInstance()->reinitialize();
+
+/** @var \Magento\TestFramework\ObjectManager $objectManager */
+$objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+
+/** @var \Magento\Catalog\Api\CategoryLinkManagementInterface $categoryLinkManagement */
+$categoryLinkManagement = $objectManager->get(\Magento\Catalog\Api\CategoryLinkManagementInterface::class);
+
+/** @var $product \Magento\Catalog\Model\Product */
+$product = $objectManager->create(\Magento\Catalog\Model\Product::class);
+$product->isObjectNew(true);
+$product->setTypeId(\Magento\Catalog\Model\Product\Type::TYPE_SIMPLE)
+    ->setAttributeSetId($product->getDefaultAttributeSetId())
+    ->setWebsiteIds([1])
+    ->setName('Simple Product')
+    ->setSku('simple-out-of-stock')
+    ->setPrice(10)
+    ->setWeight(1)
+    ->setShortDescription("Short description")
+    ->setTaxClassId(0)
+    ->setDescription('Description with <b>html tag</b>')
+    ->setMetaTitle('meta title')
+    ->setMetaKeyword('meta keyword')
+    ->setMetaDescription('meta description')
+    ->setVisibility(\Magento\Catalog\Model\Product\Visibility::VISIBILITY_BOTH)
+    ->setStatus(\Magento\Catalog\Model\Product\Attribute\Source\Status::STATUS_ENABLED)
+    ->setStockData(
+        [
+            'use_config_manage_stock'   => 1,
+            'qty'                       => 0,
+            'is_qty_decimal'            => 0,
+            'is_in_stock'               => 0,
+        ]
+    )
+    ->setCanSaveCustomOptions(true)
+    ->setHasOptions(true);
+
+/** @var \Magento\Catalog\Api\ProductRepositoryInterface $productRepositoryFactory */
+$productRepository = $objectManager->create(\Magento\Catalog\Api\ProductRepositoryInterface::class);
+$productRepository->save($product);
+
+$categoryLinkManagement->assignProductToCategories(
+    $product->getSku(),
+    [2]
+);
diff --git a/dev/tests/integration/testsuite/Magento/Catalog/_files/product_simple_out_of_stock_rollback.php b/dev/tests/integration/testsuite/Magento/Catalog/_files/product_simple_out_of_stock_rollback.php
new file mode 100644
index 0000000000000..c4df4454aa07c
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/Catalog/_files/product_simple_out_of_stock_rollback.php
@@ -0,0 +1,28 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+declare(strict_types=1);
+
+use Magento\Framework\Exception\NoSuchEntityException;
+
+\Magento\TestFramework\Helper\Bootstrap::getInstance()->getInstance()->reinitialize();
+
+/** @var \Magento\Framework\Registry $registry */
+$registry = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->get(\Magento\Framework\Registry::class);
+
+$registry->unregister('isSecureArea');
+$registry->register('isSecureArea', true);
+
+/** @var \Magento\Catalog\Api\ProductRepositoryInterface $productRepository */
+$productRepository = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()
+    ->get(\Magento\Catalog\Api\ProductRepositoryInterface::class);
+try {
+    $product = $productRepository->get('simple-out-of-stock', false, null, true);
+    $productRepository->delete($product);
+} catch (NoSuchEntityException $e) {
+}
+$registry->unregister('isSecureArea');
+$registry->register('isSecureArea', false);
diff --git a/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/ProductTest.php b/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/ProductTest.php
index 27638f4b092dd..c5e704c2434b5 100644
--- a/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/ProductTest.php
+++ b/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/ProductTest.php
@@ -271,15 +271,18 @@ public function testStockState()
     }
 
     /**
-     * Tests adding of custom options with existing and new product
+     * Tests adding of custom options with existing and new product.
      *
      * @magentoDataFixture Magento/Catalog/_files/product_simple.php
      * @dataProvider getBehaviorDataProvider
      * @param string $importFile
      * @param string $sku
+     * @param int $expectedOptionsQty
      * @magentoAppIsolation enabled
+     *
+     * @return void
      */
-    public function testSaveCustomOptions($importFile, $sku)
+    public function testSaveCustomOptions(string $importFile, string $sku, int $expectedOptionsQty): void
     {
         $pathToFile = __DIR__ . '/_files/' . $importFile;
         $importModel = $this->createImportModel($pathToFile);
@@ -312,6 +315,7 @@ public function testSaveCustomOptions($importFile, $sku)
         // assert of options data
         $this->assertCount(count($expectedData['data']), $actualData['data']);
         $this->assertCount(count($expectedData['values']), $actualData['values']);
+        $this->assertCount($expectedOptionsQty, $actualData['options']);
         foreach ($expectedData['options'] as $expectedId => $expectedOption) {
             $elementExist = false;
             // find value in actual options and values
@@ -411,17 +415,24 @@ public function testSaveCustomOptionsWithMultipleStoreViews()
     /**
      * @return array
      */
-    public function getBehaviorDataProvider()
+    public function getBehaviorDataProvider(): array
     {
         return [
             'Append behavior with existing product' => [
-                '$importFile' => 'product_with_custom_options.csv',
-                '$sku' => 'simple',
+                'importFile' => 'product_with_custom_options.csv',
+                'sku' => 'simple',
+                'expectedOptionsQty' => 6,
+            ],
+            'Append behavior with existing product and without options in import file' => [
+                'importFile' => 'product_without_custom_options.csv',
+                'sku' => 'simple',
+                'expectedOptionsQty' => 0,
             ],
             'Append behavior with new product' => [
-                '$importFile' => 'product_with_custom_options_new.csv',
-                '$sku' => 'simple_new',
-            ]
+                'importFile' => 'product_with_custom_options_new.csv',
+                'sku' => 'simple_new',
+                'expectedOptionsQty' => 4,
+            ],
         ];
     }
 
@@ -571,43 +582,45 @@ protected function getExpectedOptionsData(string $pathToFile, string $storeCode
                 break;
             }
         }
-        foreach (explode('|', $productData['data'][$storeRowId]['custom_options']) as $optionData) {
-            $option = array_values(
-                array_map(
-                    function ($input) {
-                        $data = explode('=', $input);
-                        return [$data[0] => $data[1]];
-                    },
-                    explode(',', $optionData)
-                )
-            );
-            $option = array_merge(...$option);
-
-            if (!empty($option['type']) && !empty($option['name'])) {
-                $lastOptionKey = $option['type'] . '|' . $option['name'];
-                if (!isset($expectedOptions[$expectedOptionId])
-                    || $expectedOptions[$expectedOptionId] != $lastOptionKey) {
-                    $expectedOptionId++;
-                    $expectedOptions[$expectedOptionId] = $lastOptionKey;
-                    $expectedData[$expectedOptionId] = [];
-                    foreach ($this->_assertOptions as $assertKey => $assertFieldName) {
-                        if (array_key_exists($assertFieldName, $option)
-                        && !(($assertFieldName == 'price' || $assertFieldName == 'sku')
-                                && in_array($option['type'], $this->specificTypes))
-                        ) {
-                            $expectedData[$expectedOptionId][$assertKey] = $option[$assertFieldName];
+        if (!empty($productData['data'][$storeRowId]['custom_options'])) {
+            foreach (explode('|', $productData['data'][$storeRowId]['custom_options']) as $optionData) {
+                $option = array_values(
+                    array_map(
+                        function ($input) {
+                            $data = explode('=', $input);
+                            return [$data[0] => $data[1]];
+                        },
+                        explode(',', $optionData)
+                    )
+                );
+                $option = array_merge(...$option);
+
+                if (!empty($option['type']) && !empty($option['name'])) {
+                    $lastOptionKey = $option['type'] . '|' . $option['name'];
+                    if (!isset($expectedOptions[$expectedOptionId])
+                        || $expectedOptions[$expectedOptionId] != $lastOptionKey) {
+                        $expectedOptionId++;
+                        $expectedOptions[$expectedOptionId] = $lastOptionKey;
+                        $expectedData[$expectedOptionId] = [];
+                        foreach ($this->_assertOptions as $assertKey => $assertFieldName) {
+                            if (array_key_exists($assertFieldName, $option)
+                                && !(($assertFieldName == 'price' || $assertFieldName == 'sku')
+                                    && in_array($option['type'], $this->specificTypes))
+                            ) {
+                                $expectedData[$expectedOptionId][$assertKey] = $option[$assertFieldName];
+                            }
                         }
                     }
                 }
-            }
-            $optionValue = [];
-            if (!empty($option['name']) && !empty($option['option_title'])) {
-                foreach ($this->_assertOptionValues as $assertKey => $assertFieldName) {
-                    if (isset($option[$assertFieldName])) {
-                        $optionValue[$assertKey] = $option[$assertFieldName];
+                $optionValue = [];
+                if (!empty($option['name']) && !empty($option['option_title'])) {
+                    foreach ($this->_assertOptionValues as $assertKey => $assertFieldName) {
+                        if (isset($option[$assertFieldName])) {
+                            $optionValue[$assertKey] = $option[$assertFieldName];
+                        }
                     }
+                    $expectedValues[$expectedOptionId][] = $optionValue;
                 }
-                $expectedValues[$expectedOptionId][] = $optionValue;
             }
         }
 
@@ -2181,4 +2194,51 @@ public function testProductsWithMultipleStoresWhenMediaIsDisabled(): void
         $this->assertTrue($errors->getErrorsCount() === 0);
         $this->assertTrue($this->_model->importData());
     }
+
+    /**
+     * Test that imported product stock status with backorders functionality enabled can be set to 'out of stock'.
+     *
+     * @magentoDbIsolation enabled
+     * @magentoAppIsolation enabled
+     *
+     * @return void
+     */
+    public function testImportWithBackordersEnabled(): void
+    {
+        $this->importFile('products_to_import_with_backorders_enabled_and_0_qty.csv');
+        $product = $this->getProductBySku('simple_new');
+        $this->assertFalse($product->getDataByKey('quantity_and_stock_status')['is_in_stock']);
+    }
+
+    /**
+     * Import file by providing import filename in parameters.
+     *
+     * @param string $fileName
+     * @return void
+     */
+    private function importFile(string $fileName): void
+    {
+        $filesystem = $this->objectManager->create(\Magento\Framework\Filesystem::class);
+        $directory = $filesystem->getDirectoryWrite(DirectoryList::ROOT);
+        $source = $this->objectManager->create(
+            \Magento\ImportExport\Model\Import\Source\Csv::class,
+            [
+                'file' => __DIR__ . '/_files/' . $fileName,
+                'directory' => $directory,
+            ]
+        );
+        $errors = $this->_model->setParameters(
+            [
+                'behavior' => \Magento\ImportExport\Model\Import::BEHAVIOR_APPEND,
+                'entity' => 'catalog_product',
+                \Magento\ImportExport\Model\Import::FIELDS_ENCLOSURE => 1,
+            ]
+        )
+        ->setSource($source)
+        ->validateData();
+
+        $this->assertTrue($errors->getErrorsCount() == 0);
+
+        $this->_model->importData();
+    }
 }
diff --git a/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/_files/product_without_custom_options.csv b/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/_files/product_without_custom_options.csv
new file mode 100644
index 0000000000000..17bffb427a0e9
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/_files/product_without_custom_options.csv
@@ -0,0 +1,2 @@
+sku,website_code,store_view_code,attribute_set_code,product_type,name,description,short_description,weight,product_online,visibility,product_websites,categories,price,special_price,special_price_from_date,special_price_to_date,tax_class_name,url_key,meta_title,meta_keywords,meta_description,base_image,base_image_label,small_image,small_image_label,thumbnail_image,thumbnail_image_label,additional_images,additional_image_labels,configurable_variation_labels,configurable_variations,bundle_price_type,bundle_sku_type,bundle_weight_type,bundle_values,downloadble_samples,downloadble_links,associated_skus,related_skus,crosssell_skus,upsell_skus,custom_options,additional_attributes,manage_stock,is_in_stock,qty,out_of_stock_qty,is_qty_decimal,allow_backorders,min_cart_qty,max_cart_qty,notify_on_stock_below,qty_increments,enable_qty_increments,is_decimal_divided,new_from_date,new_to_date,gift_message_available,created_at,updated_at,custom_design,custom_design_from,custom_design_to,custom_layout_update,page_layout,product_options_container,msrp_price,msrp_display_actual_price_type,map_enabled
+simple,base,,Default,simple,New Product,,,9,1,"Catalog, Search",base,,10,,,,Taxable Goods,new-product,,,,,,,,,,,,,,,,,,,,,,,,,,1,1,999,0,0,0,1,10000,1,1,0,0,,,,,,,,,,,Block after Info Column,,,
diff --git a/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/_files/products_to_import_with_backorders_enabled_and_0_qty.csv b/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/_files/products_to_import_with_backorders_enabled_and_0_qty.csv
new file mode 100644
index 0000000000000..e2107766c37bd
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogImportExport/Model/Import/_files/products_to_import_with_backorders_enabled_and_0_qty.csv
@@ -0,0 +1,2 @@
+sku,store_view_code,attribute_set_code,product_type,categories,product_websites,name,description,short_description,weight,product_online,tax_class_name,visibility,price,special_price,special_price_from_date,special_price_to_date,url_key,meta_title,meta_keywords,meta_description,base_image,base_image_label,small_image,small_image_label,thumbnail_image,thumbnail_image_label,created_at,updated_at,new_from_date,new_to_date,display_product_options_in,map_price,msrp_price,map_enabled,gift_message_available,custom_design,custom_design_from,custom_design_to,custom_layout_update,page_layout,product_options_container,msrp_display_actual_price_type,country_of_manufacture,additional_attributes,qty,out_of_stock_qty,use_config_min_qty,is_qty_decimal,allow_backorders,use_config_backorders,min_cart_qty,use_config_min_sale_qty,max_cart_qty,use_config_max_sale_qty,is_in_stock,notify_on_stock_below,use_config_notify_stock_qty,manage_stock,use_config_manage_stock,use_config_qty_increments,qty_increments,use_config_enable_qty_inc,enable_qty_increments,is_decimal_divided,website_id,related_skus,crosssell_skus,upsell_skus,additional_images,additional_image_labels,hide_from_product_page,custom_options,bundle_price_type,bundle_sku_type,bundle_price_view,bundle_weight_type,bundle_values,associated_skus
+simple_new,,Default,simple,,base,New Product,,,,1,Taxable Goods,"Catalog, Search",10,,,,new-product,New Product,New Product,New Product ,,,,,,,10/20/2015 7:05,10/20/2015 7:05,,,Block after Info Column,,,,,,,,,,,,,"has_options=1,quantity_and_stock_status=In Stock,required_options=1",0,0,1,0,1,0,1,1,10000,1,0,1,1,1,0,1,1,0,0,0,1,,,,,,,,,,,,,
diff --git a/dev/tests/integration/testsuite/Magento/CatalogRule/Model/Indexer/Product/PriceTest.php b/dev/tests/integration/testsuite/Magento/CatalogRule/Model/Indexer/Product/PriceTest.php
new file mode 100644
index 0000000000000..b1a10c894f83a
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogRule/Model/Indexer/Product/PriceTest.php
@@ -0,0 +1,92 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogRule\Model\Indexer\Product;
+
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\CatalogRule\Model\ResourceModel\Rule;
+use Magento\Catalog\Model\ResourceModel\Product\Collection;
+use Magento\Catalog\Api\ProductRepositoryInterface;
+use Magento\Framework\Api\SearchCriteriaInterface;
+use Magento\Framework\Api\SortOrder;
+
+/**
+ * @magentoDataFixtureBeforeTransaction Magento/CatalogRule/_files/attribute.php
+ * @magentoDataFixtureBeforeTransaction Magento/CatalogRule/_files/product_with_attribute.php
+ * @magentoDataFixtureBeforeTransaction Magento/CatalogRule/_files/rule_by_attribute.php
+ * @magentoDbIsolation enabled
+ * @magentoAppIsolation enabled
+ */
+class PriceTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var Rule
+     */
+    private $resourceRule;
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function setUp()
+    {
+        $this->resourceRule = Bootstrap::getObjectManager()->get(Rule::class);
+    }
+
+    /**
+     * @return void
+     */
+    public function testPriceApplying() : void
+    {
+        $customerGroupId = 1;
+        $websiteId = 1;
+
+        $simpleProductId = 1;
+        $collection = Bootstrap::getObjectManager()->create(Collection::class);
+        $collection->addIdFilter($simpleProductId);
+        $collection->addPriceData($customerGroupId, $websiteId);
+        $collection->load();
+        /** @var \Magento\Catalog\Model\Product $simpleProduct */
+        $simpleProduct = $collection->getFirstItem();
+        $simpleProduct->setPriceCalculation(false);
+
+        $rulePrice = $this->resourceRule->getRulePrice(new \DateTime(), $websiteId, $customerGroupId, $simpleProductId);
+        $this->assertEquals($rulePrice, $simpleProduct->getFinalPrice());
+
+        $confProductId = 666;
+        $collection = Bootstrap::getObjectManager()->create(Collection::class);
+        $collection->addIdFilter($confProductId);
+        $collection->addPriceData($customerGroupId, $websiteId);
+        $collection->load();
+        /** @var \Magento\Catalog\Model\Product $confProduct */
+        $confProduct = $collection->getFirstItem();
+
+        $this->assertEquals($simpleProduct->getMinimalPrice(), $confProduct->getMinimalPrice());
+    }
+
+    /**
+     * @magentoAppArea frontend
+     *
+     * @return void
+     */
+    public function testSortByPrice() : void
+    {
+        $searchCriteria = Bootstrap::getObjectManager()->create(SearchCriteriaInterface::class);
+        $sortOrder = Bootstrap::getObjectManager()->create(SortOrder::class);
+        $sortOrder->setField('price')->setDirection(SortOrder::SORT_ASC);
+        $searchCriteria->setSortOrders([$sortOrder]);
+        $productRepository = Bootstrap::getObjectManager()->get(ProductRepositoryInterface::class);
+        $searchResults = $productRepository->getList($searchCriteria);
+        $products = $searchResults->getItems();
+
+        /** @var \Magento\Catalog\Model\Product $product1 */
+        $product1 = array_values($products)[0];
+        $product1->setPriceCalculation(false);
+        $this->assertEquals('simple1', $product1->getSku());
+        $rulePrice = $this->resourceRule->getRulePrice(new \DateTime(), 1, 1, $product1->getId());
+        $this->assertEquals($rulePrice, $product1->getFinalPrice());
+    }
+}
diff --git a/dev/tests/integration/testsuite/Magento/CatalogRule/Model/Indexer/RuleProductTest.php b/dev/tests/integration/testsuite/Magento/CatalogRule/Model/Indexer/RuleProductTest.php
index c8c0726de7ebe..a4a99918fe052 100644
--- a/dev/tests/integration/testsuite/Magento/CatalogRule/Model/Indexer/RuleProductTest.php
+++ b/dev/tests/integration/testsuite/Magento/CatalogRule/Model/Indexer/RuleProductTest.php
@@ -40,7 +40,7 @@ protected function setUp()
     public function testReindexAfterRuleCreation()
     {
         /** @var \Magento\Catalog\Model\ProductRepository $productRepository */
-        $productRepository = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create(
+        $productRepository = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->get(
             \Magento\Catalog\Model\ProductRepository::class
         );
         $product = $productRepository->get('simple');
diff --git a/dev/tests/integration/testsuite/Magento/CatalogRule/_files/product_with_attribute.php b/dev/tests/integration/testsuite/Magento/CatalogRule/_files/product_with_attribute.php
new file mode 100644
index 0000000000000..071f5d7d9fd00
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogRule/_files/product_with_attribute.php
@@ -0,0 +1,108 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+require __DIR__ . '/../../ConfigurableProduct/_files/configurable_attribute.php';
+
+$objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+
+$storeManager = $objectManager->get(\Magento\Store\Model\StoreManager::class);
+$store = $storeManager->getStore('default');
+
+$productRepository = $objectManager->get(\Magento\Catalog\Api\ProductRepositoryInterface::class);
+
+$installer = $objectManager->get(\Magento\Catalog\Setup\CategorySetup::class);
+$attributeSetId = $installer->getAttributeSetId('catalog_product', 'Default');
+$attributeValues = [];
+$associatedProductIds = [];
+
+/** @var Magento\Eav\Model\Entity\Attribute\Option[] $options */
+$options = $attribute->getOptions();
+array_shift($options); //remove the first option which is empty
+
+$product = $objectManager->create(\Magento\Catalog\Model\Product::class)
+    ->setTypeId('simple')
+    ->setId(1)
+    ->setAttributeSetId($attributeSetId)
+    ->setWebsiteIds([1])
+    ->setName('Simple Product 1')
+    ->setSku('simple1')
+    ->setPrice(10)
+    ->setVisibility(\Magento\Catalog\Model\Product\Visibility::VISIBILITY_BOTH)
+    ->setStatus(\Magento\Catalog\Model\Product\Attribute\Source\Status::STATUS_ENABLED)
+    ->setStockData([
+        'use_config_manage_stock' => 1,
+        'qty' => 100,
+        'is_qty_decimal' => 0,
+        'is_in_stock' => 1,
+    ]);
+$option = array_shift($options);
+$product->setTestConfigurable($option->getValue());
+$productRepository->save($product);
+$attributeValues[] = [
+    'label' => 'test',
+    'attribute_id' => $attribute->getId(),
+    'value_index' => $option->getValue(),
+];
+$associatedProductIds[] = $product->getId();
+$productAction = $objectManager->get(\Magento\Catalog\Model\Product\Action::class);
+$productAction->updateAttributes([$product->getId()], ['test_attribute' => 'test_attribute_value'], $store->getId());
+
+$product = $objectManager->create(\Magento\Catalog\Model\Product::class)
+    ->setTypeId('simple')
+    ->setId(2)
+    ->setAttributeSetId($attributeSetId)
+    ->setWebsiteIds([1])
+    ->setName('Simple Product 2')
+    ->setSku('simple2')
+    ->setPrice(9.9)
+    ->setVisibility(\Magento\Catalog\Model\Product\Visibility::VISIBILITY_BOTH)
+    ->setStatus(\Magento\Catalog\Model\Product\Attribute\Source\Status::STATUS_ENABLED)
+    ->setStockData([
+        'use_config_manage_stock' => 1,
+        'qty' => 100,
+        'is_qty_decimal' => 0,
+        'is_in_stock' => 1,
+    ]);
+$option = array_shift($options);
+$product->setTestConfigurable($option->getValue());
+$productRepository->save($product);
+$attributeValues[] = [
+    'label' => 'test',
+    'attribute_id' => $attribute->getId(),
+    'value_index' => $option->getValue(),
+];
+$associatedProductIds[] = $product->getId();
+
+$product = $objectManager->create(\Magento\Catalog\Model\Product::class)
+    ->setTypeId('configurable')
+    ->setId(666)
+    ->setAttributeSetId($attributeSetId)
+    ->setWebsiteIds([1])
+    ->setName('Configurable Product')
+    ->setSku('configurable')
+    ->setVisibility(\Magento\Catalog\Model\Product\Visibility::VISIBILITY_BOTH)
+    ->setStatus(\Magento\Catalog\Model\Product\Attribute\Source\Status::STATUS_ENABLED)
+    ->setStockData([
+        'use_config_manage_stock' => 1,
+        'is_in_stock' => 0,
+    ]);
+$configurableAttributesData = [
+    [
+        'attribute_id' => $attribute->getId(),
+        'code' => $attribute->getAttributeCode(),
+        'label' => $attribute->getStoreLabel(),
+        'position' => '0',
+        'values' => $attributeValues,
+    ],
+];
+$optionsFactory = $objectManager->get(\Magento\ConfigurableProduct\Helper\Product\Options\Factory::class);
+$configurableOptions = $optionsFactory->create($configurableAttributesData);
+$extensionConfigurableAttributes = $product->getExtensionAttributes();
+$extensionConfigurableAttributes->setConfigurableProductOptions($configurableOptions);
+$extensionConfigurableAttributes->setConfigurableProductLinks($associatedProductIds);
+$product->setExtensionAttributes($extensionConfigurableAttributes);
+$productRepository->save($product);
diff --git a/dev/tests/integration/testsuite/Magento/CatalogRule/_files/product_with_attribute_rollback.php b/dev/tests/integration/testsuite/Magento/CatalogRule/_files/product_with_attribute_rollback.php
new file mode 100644
index 0000000000000..0ce909a3f9ecd
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogRule/_files/product_with_attribute_rollback.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+\Magento\TestFramework\Helper\Bootstrap::getInstance()->getInstance()->reinitialize();
+
+/** @var $objectManager \Magento\TestFramework\ObjectManager */
+$objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+
+/** @var \Magento\Framework\Registry $registry */
+$registry = $objectManager->get(\Magento\Framework\Registry::class);
+
+$registry->unregister('isSecureArea');
+$registry->register('isSecureArea', true);
+
+/** @var \Magento\Catalog\Api\ProductRepositoryInterface $productRepository */
+$productRepository = $objectManager->get(\Magento\Catalog\Api\ProductRepositoryInterface::class);
+foreach (['simple1', 'simple2', 'configurable'] as $sku) {
+    try {
+        $product = $productRepository->get($sku, false, null, true);
+        $productRepository->delete($product);
+    } catch (\Magento\Framework\Exception\NoSuchEntityException $e) {
+        //Nothing to delete
+    }
+}
+
+$registry->unregister('isSecureArea');
+$registry->register('isSecureArea', false);
+
+require __DIR__ . '/../../ConfigurableProduct/_files/configurable_attribute_rollback.php';
diff --git a/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/Plugin/Store/Block/SwitcherTest.php b/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/Plugin/Store/Block/SwitcherTest.php
new file mode 100644
index 0000000000000..5b3879b592245
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/Plugin/Store/Block/SwitcherTest.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogUrlRewrite\Plugin\Store\Block;
+
+/**
+ * Integration tests for Magento\CatalogUrlRewrite\Plugin\Store\Block\Switcher block.
+ */
+class SwitcherTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @var \Magento\TestFramework\ObjectManager
+     */
+    private $objectManager;
+
+    /**
+     * @var \Magento\Store\Block\Switcher
+     */
+    private $model;
+
+    /**
+     * @var \Magento\Store\Api\StoreRepositoryInterface
+     */
+    private $storeRepository;
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function setUp()
+    {
+        $this->objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+        $this->model = $this->objectManager->create(\Magento\Store\Block\Switcher::class);
+        $this->storeRepository = $this->objectManager->create(\Magento\Store\Api\StoreRepositoryInterface::class);
+    }
+
+    /**
+     * Test that after switching from Store 1 to Store 2 with another root Category user gets correct store url.
+     *
+     * @magentoDataFixture Magento/Store/_files/store.php
+     * @magentoDataFixture Magento/CatalogUrlRewrite/_files/two_categories_per_two_store_groups.php
+     * @magentoAppArea frontend
+     * @return void
+     */
+    public function testGetTargetStorePostData(): void
+    {
+        $storeCode = 'test';
+        $store = $this->storeRepository->get($storeCode);
+        $result = json_decode($this->model->getTargetStorePostData($store), true);
+        
+        $this->assertContains($storeCode, $result['action']);
+    }
+}
diff --git a/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/_files/two_categories_per_two_store_groups.php b/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/_files/two_categories_per_two_store_groups.php
new file mode 100644
index 0000000000000..90a74351d8200
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/_files/two_categories_per_two_store_groups.php
@@ -0,0 +1,70 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+$objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+$defaultCategory = $objectManager->create(\Magento\Catalog\Helper\DefaultCategory::class);
+/** @var \Magento\Catalog\Model\Category $category */
+$category = $objectManager->create(\Magento\Catalog\Model\Category::class);
+$category->isObjectNew(true);
+$category->setCreatedAt('2014-06-23 09:50:07')
+    ->setName('Category 1')
+    ->setParentId($defaultCategory->getId())
+    ->setPath('1/2/3')
+    ->setLevel(2)
+    ->setAvailableSortBy('name')
+    ->setDefaultSortBy('name')
+    ->setIsActive(true)
+    ->setPosition(1)
+    ->setAvailableSortBy(['position'])
+    ->save();
+
+/** @var \Magento\Store\Model\Store $store */
+$store = $objectManager->create(\Magento\Store\Model\Store::class);
+
+$category->setStoreId($store->load('default')->getId())
+    ->setName('category-default-store')
+    ->setUrlKey('category-default-store')
+    ->save();
+
+$rootCategoryForTestStoreGroup = $objectManager->create(\Magento\Catalog\Model\Category::class);
+$rootCategoryForTestStoreGroup->isObjectNew(true);
+$rootCategoryForTestStoreGroup->setCreatedAt('2014-06-23 09:50:07')
+    ->setName('Category 2')
+    ->setParentId(\Magento\Catalog\Model\Category::TREE_ROOT_ID)
+    ->setPath('1/2/334')
+    ->setLevel(2)
+    ->setAvailableSortBy('name')
+    ->setDefaultSortBy('name')
+    ->setIsActive(true)
+    ->setPosition(1)
+    ->setAvailableSortBy(['position'])
+    ->save();
+
+$rootCategoryForTestStoreGroup->setStoreId($store->load('test')->getId())
+    ->setName('category-test-store')
+    ->setUrlKey('category-test-store')
+    ->save();
+
+$storeCode = 'test';
+/** @var \Magento\Store\Api\StoreRepositoryInterface $storeRepository */
+$storeRepository = $objectManager->create(\Magento\Store\Api\StoreRepositoryInterface::class);
+/** @var \Magento\Store\Api\Data\StoreInterface $store */
+$store = $storeRepository->get($storeCode);
+
+/** @var \Magento\Store\Model\Group $storeGroup */
+$storeGroup = $objectManager->create(\Magento\Store\Model\Group::class)
+    ->setWebsiteId('1')
+    ->setCode('test_store_group')
+    ->setName('Test Store Group')
+    ->setRootCategoryId($rootCategoryForTestStoreGroup->getId())
+    ->setDefaultStoreId($store->getId())
+    ->save();
+
+$store->setGroupId($storeGroup->getId())->save();
+
+/* Refresh stores memory cache */
+$objectManager->get(\Magento\Store\Model\StoreManagerInterface::class)->reinitStores();
diff --git a/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/_files/two_categories_per_two_store_groups_rollback.php b/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/_files/two_categories_per_two_store_groups_rollback.php
new file mode 100644
index 0000000000000..9592e9d0e69b4
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/CatalogUrlRewrite/_files/two_categories_per_two_store_groups_rollback.php
@@ -0,0 +1,47 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+use Magento\Framework\Registry;
+use Magento\Store\Model\Group;
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\Catalog\Api\CategoryListInterface;
+use Magento\Catalog\Api\CategoryRepositoryInterface;
+use Magento\Framework\Api\SearchCriteriaBuilder;
+
+$objectManager = Bootstrap::getObjectManager();
+
+/** @var Registry $registry */
+$registry = $objectManager->get(Registry::class);
+$registry->unregister('isSecureArea');
+$registry->register('isSecureArea', true);
+// Delete first category
+/** @var SearchCriteriaBuilder $searchCriteriaBuilder */
+$searchCriteriaBuilder = $objectManager->get(SearchCriteriaBuilder::class);
+$searchCriteria = $searchCriteriaBuilder->addFilter('name', 'Category 1')->create();
+/** @var CategoryListInterface $categoryList */
+$categoryList = $objectManager->get(CategoryListInterface::class);
+$categories = $categoryList->getList($searchCriteria)->getItems();
+/** @var CategoryRepositoryInterface $categoryRepository */
+$categoryRepository = $objectManager->get(CategoryRepositoryInterface::class);
+foreach ($categories as $category) {
+    $categoryRepository->delete($category);
+}
+// Delete second category
+$searchCriteria = $searchCriteriaBuilder->addFilter('name', 'Category 2')->create();
+$categories = $categoryList->getList($searchCriteria)->getItems();
+foreach ($categories as $category) {
+    $categoryRepository->delete($category);
+}
+// Delete store group
+/** @var Group $store */
+$storeGroup = $objectManager->get(Group::class);
+$storeGroup->load('test_store_group', 'code');
+if ($storeGroup->getId()) {
+    $storeGroup->delete();
+}
+$registry->unregister('isSecureArea');
+$registry->register('isSecureArea', false);
diff --git a/dev/tests/integration/testsuite/Magento/Tax/_files/tax_classes.php b/dev/tests/integration/testsuite/Magento/Tax/_files/tax_classes.php
index 95f69b1e522ee..515cda55ec584 100644
--- a/dev/tests/integration/testsuite/Magento/Tax/_files/tax_classes.php
+++ b/dev/tests/integration/testsuite/Magento/Tax/_files/tax_classes.php
@@ -38,6 +38,15 @@
     \Magento\Tax\Model\ClassModel::TAX_CLASS_TYPE_PRODUCT
 )->save();
 
+// Tax class created but not used in the rule to ensure that unused tax classes are handled properly
+$productTaxClass3 = $objectManager->create(
+    \Magento\Tax\Model\ClassModel::class
+)->setClassName(
+    'ProductTaxClass3'
+)->setClassType(
+    \Magento\Tax\Model\ClassModel::TAX_CLASS_TYPE_PRODUCT
+)->save();
+
 $taxRate = [
     'tax_country_id' => 'US',
     'tax_region_id' => '12',
diff --git a/dev/tests/integration/testsuite/Magento/Tax/_files/tax_classes_rollback.php b/dev/tests/integration/testsuite/Magento/Tax/_files/tax_classes_rollback.php
new file mode 100644
index 0000000000000..51ba48b881736
--- /dev/null
+++ b/dev/tests/integration/testsuite/Magento/Tax/_files/tax_classes_rollback.php
@@ -0,0 +1,43 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+/** @var $objectManager \Magento\TestFramework\ObjectManager */
+$objectManager = \Magento\TestFramework\Helper\Bootstrap::getObjectManager();
+
+$taxRules = [
+    'Test Rule',
+    'Test Rule Duplicate',
+];
+$taxClasses = [
+    'ProductTaxClass1',
+    'ProductTaxClass2',
+    'ProductTaxClass3',
+    'CustomerTaxClass1',
+    'CustomerTaxClass2',
+];
+
+
+$taxRuleResource = $objectManager->get(\Magento\Tax\Model\ResourceModel\Calculation\Rule::class);
+foreach ($taxRules as $taxRuleCode) {
+    $taxRule = $objectManager->create(\Magento\Tax\Model\Calculation\Rule::class);
+    $taxRuleResource->load($taxRule, $taxRuleCode, 'code');
+    $taxRuleResource->delete($taxRule);
+}
+
+/** @var \Magento\Tax\Model\ResourceModel\TaxClass $resourceModel */
+$resourceModel = $objectManager->get(\Magento\Tax\Model\ResourceModel\TaxClass::class);
+
+foreach ($taxClasses as $taxClass) {
+    try {
+        /** @var \Magento\Tax\Model\ClassModel $taxClassEntity */
+        $taxClassEntity = $objectManager->create(\Magento\Tax\Model\ClassModel::class);
+        $resourceModel->load($taxClassEntity, $taxClass, 'class_name');
+        $resourceModel->delete($taxClassEntity);
+    } catch (\Magento\Framework\Exception\CouldNotDeleteException $couldNotDeleteException) {
+        // It's okay if the entity already wiped from the database
+    }
+}
diff --git a/lib/internal/Magento/Framework/Exception/AbstractAggregateException.php b/lib/internal/Magento/Framework/Exception/AbstractAggregateException.php
index 92a850511295a..ff142c5319006 100644
--- a/lib/internal/Magento/Framework/Exception/AbstractAggregateException.php
+++ b/lib/internal/Magento/Framework/Exception/AbstractAggregateException.php
@@ -78,6 +78,10 @@ public function addError(Phrase $phrase)
         return $this;
     }
 
+    /**
+     * @param LocalizedException $exception
+     * @return $this
+     */
     public function addException(LocalizedException $exception)
     {
         $this->addErrorCalls++;
diff --git a/lib/internal/Magento/Framework/GraphQl/Query/Resolver/Argument/Filter/Operator.php b/lib/internal/Magento/Framework/GraphQl/Query/Resolver/Argument/Filter/Operator.php
index acd656e70ec62..ae2b8bfeabd1b 100644
--- a/lib/internal/Magento/Framework/GraphQl/Query/Resolver/Argument/Filter/Operator.php
+++ b/lib/internal/Magento/Framework/GraphQl/Query/Resolver/Argument/Filter/Operator.php
@@ -65,7 +65,7 @@ public static function getOperators() : array
         return $type->getConstants();
     }
 
-    /*
+    /**
      * Convert operator to string
      *
      * @return string
diff --git a/lib/internal/Magento/Framework/Webapi/Test/Unit/ServiceInputProcessor/SimpleConstructor.php b/lib/internal/Magento/Framework/Webapi/Test/Unit/ServiceInputProcessor/SimpleConstructor.php
index f457a96e22a37..f875861e42b02 100644
--- a/lib/internal/Magento/Framework/Webapi/Test/Unit/ServiceInputProcessor/SimpleConstructor.php
+++ b/lib/internal/Magento/Framework/Webapi/Test/Unit/ServiceInputProcessor/SimpleConstructor.php
@@ -19,6 +19,10 @@ class SimpleConstructor
      */
     private $name;
 
+    /**
+     * @param int $entityId
+     * @param string $name
+     */
     public function __construct(
         int $entityId,
         string $name
diff --git a/lib/web/mage/dropdowns.js b/lib/web/mage/dropdowns.js
index 6c1389924a24b..1496a1c65d957 100644
--- a/lib/web/mage/dropdowns.js
+++ b/lib/web/mage/dropdowns.js
@@ -127,11 +127,9 @@ define([
             }
 
             elem.on('click.toggleDropdown', function () {
-                var el;
+                var el = actionElem;
 
                 if (options.autoclose === true) {
-                    el = actionElem;
-
                     actionElem = $();
                     $(document).trigger('click.hideDropdown');
                     actionElem = el;
diff --git a/setup/src/Magento/Setup/Console/Command/GenerateFixturesCommand.php b/setup/src/Magento/Setup/Console/Command/GenerateFixturesCommand.php
index e084cd8ff6cad..03b74f637a7da 100644
--- a/setup/src/Magento/Setup/Console/Command/GenerateFixturesCommand.php
+++ b/setup/src/Magento/Setup/Console/Command/GenerateFixturesCommand.php
@@ -157,6 +157,10 @@ private function clearChangelog()
         }
     }
 
+    /**
+     * @param \Magento\Setup\Fixtures\Fixture $fixture
+     * @param OutputInterface $output
+     */
     private function executeFixture(\Magento\Setup\Fixtures\Fixture $fixture, OutputInterface $output)
     {
         $output->write('<info>' . $fixture->getActionTitle() . '... </info>');
diff --git a/setup/src/Magento/Setup/Console/Style/MagentoStyle.php b/setup/src/Magento/Setup/Console/Style/MagentoStyle.php
index c3f292ce76e1e..cd2d4a77db65a 100755
--- a/setup/src/Magento/Setup/Console/Style/MagentoStyle.php
+++ b/setup/src/Magento/Setup/Console/Style/MagentoStyle.php
@@ -518,6 +518,10 @@ private function autoPrependText()
         }
     }
 
+    /**
+     * @param array $messages
+     * @return array
+     */
     private function reduceBuffer($messages)
     {
         // We need to know if the two last chars are PHP_EOL