Category product count does not include products assigned to the category itself

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

@@ -412,14 +412,21 @@ private function getCountFromCategoryTableBulk(
                 []
             )
             ->where('ce.entity_id IN (?)', $categoryIds);
-
         $connection->query(
             $connection->insertFromSelect(
                 $selectDescendants,
                 $tempTableName,
                 ['category_id', 'descendant_id']
             )
         );
+        $data = [];
+        foreach ($categoryIds as $catId) {
+            $data[] = [
+                'category_id' => $catId,
+                'descendant_id' => $catId
+            ];
+        }
+        $connection->insertMultiple($tempTableName, $data);
         $select = $connection->select()
             ->from(
                 ['t' => $tempTableName],

app/code/Magento/Catalog/Test/Unit/Helper/CategoryTestHelper.php

@@ -0,0 +1,27 @@
+<?php
+/**
+ * Copyright 2025 Adobe
+ * All Rights Reserved.
+ */
+declare(strict_types=1);
+
+namespace Magento\Catalog\Test\Unit\Helper;
+
+use Magento\Catalog\Model\Category;
+
+/**
+ * Test helper class for Catalog Category with custom methods
+ */
+class CategoryTestHelper extends Category
+{
+
+    /**
+     * Get is anchor
+     *
+     * @return bool
+     */
+    public function getIsAnchor(): bool
+    {
+        return $this->getData('is_anchor');
+    }
+}

app/code/Magento/Catalog/Test/Unit/Model/ResourceModel/Category/CollectionTest.php

@@ -7,27 +7,27 @@
 
 namespace Magento\Catalog\Test\Unit\Model\ResourceModel\Category;
 
-use Magento\Catalog\Model\Category;
-use Magento\Framework\Data\Collection\EntityFactory;
-use Magento\Store\Model\Store;
-use Psr\Log\LoggerInterface;
-use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
-use Magento\Framework\Event\ManagerInterface;
+use Magento\Catalog\Model\Product\Visibility;
+use Magento\Catalog\Model\ResourceModel\Category as CategoryEntity;
+use Magento\Catalog\Model\ResourceModel\Category\Collection;
+use Magento\Catalog\Test\Unit\Helper\CategoryTestHelper;
 use Magento\Eav\Model\Config;
-use Magento\Framework\App\ResourceConnection;
 use Magento\Eav\Model\EntityFactory as EavEntityFactory;
 use Magento\Eav\Model\ResourceModel\Helper;
-use Magento\Framework\Validator\UniversalFactory;
-use Magento\Store\Model\StoreManagerInterface;
-use Magento\Store\Api\Data\StoreInterface;
+use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Framework\App\ResourceConnection;
+use Magento\Framework\Data\Collection\Db\FetchStrategyInterface;
+use Magento\Framework\Data\Collection\EntityFactory;
 use Magento\Framework\DB\Adapter\AdapterInterface;
 use Magento\Framework\DB\Select;
-use Magento\Framework\App\Config\ScopeConfigInterface;
-use Magento\Catalog\Model\Product\Visibility;
-use Magento\Catalog\Model\ResourceModel\Category\Collection;
-use Magento\Catalog\Model\ResourceModel\Category as CategoryEntity;
+use Magento\Framework\Event\ManagerInterface;
+use Magento\Framework\Validator\UniversalFactory;
+use Magento\Store\Api\Data\StoreInterface;
+use Magento\Store\Model\Store;
+use Magento\Store\Model\StoreManagerInterface;
 use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
 
 /**
  * @SuppressWarnings(PHPMD.TooManyFields)
@@ -229,11 +229,7 @@ public function testLoadProductCountCallsBulkMethodForLargeCategoryCount()
         $items = [];
         $categoryIds = [];
         for ($i = 1; $i <= $categoryCount; $i++) {
-            $category = $this->getMockBuilder(Category::class)
-                ->addMethods(['getIsAnchor'])
-                ->onlyMethods(['getId', 'setProductCount'])
-                ->disableOriginalConstructor()
-                ->getMock();
+            $category = $this->createMock(CategoryTestHelper::class);
             $category->method('getId')->willReturn($i);
             $category->method('getIsAnchor')->willReturn(true);
             $category->expects($this->once())->method('setProductCount')->with(5);
@@ -265,6 +261,20 @@ public function testLoadProductCountCallsBulkMethodForLargeCategoryCount()
         $this->connection->method('select')->willReturn($this->select);
         $this->connection->method('insertFromSelect')->willReturn('INSERT QUERY');
         $this->connection->method('query')->with('INSERT QUERY')->willReturnSelf();
+        $withs = [];
+        foreach ($categoryIds as $categoryId) {
+            $withs[] = [
+                'category_id' => $categoryId,
+                'descendant_id' => $categoryId
+            ];
+        }
+        $this->connection
+            ->expects($this->once())
+            ->method('insertMultiple')
+            ->with(
+                $this->stringContains('temp_category_descendants_'),
+                $withs
+            );
         $this->select->method('from')->willReturnSelf();
         $this->select->method('joinLeft')->willReturnSelf();
         $this->select->method('join')->willReturnSelf();

dev/tests/integration/testsuite/Magento/Catalog/Model/ResourceModel/Category/CollectionTest.php

@@ -1,35 +1,38 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2018 Adobe
+ * All Rights Reserved.
  */
 declare(strict_types=1);
 
 namespace Magento\Catalog\Model\ResourceModel\Category;
 
+use Magento\Store\Model\StoreManagerInterface;
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\Catalog\Model\ResourceModel\Category\Collection as CategoryCollection;
+use Magento\Catalog\Model\ResourceModel\Category\CollectionFactory;
+
 class CollectionTest extends \PHPUnit\Framework\TestCase
 {
-    /**
-     * @var \Magento\Catalog\Model\ResourceModel\Category\Collection
-     */
-    private $collection;
+    private Collection $collection;
+    private CollectionFactory $categoryCollectionFactory;
 
     /**
      * Sets up the fixture, for example, opens a network connection.
      * This method is called before a test is executed.
      */
     protected function setUp(): void
     {
-        $this->collection = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->create(
-            \Magento\Catalog\Model\ResourceModel\Category\Collection::class
-        );
+        $objectManager = Bootstrap::getObjectManager();
+        $this->collection = Bootstrap::getObjectManager()->create(Collection::class);
+        $this->categoryCollectionFactory = $objectManager->get(CollectionFactory::class);
     }
 
-    protected function setDown()
+    protected function tearDown(): void
     {
         /* Refresh stores memory cache after store deletion */
-        \Magento\TestFramework\Helper\Bootstrap::getObjectManager()->get(
-            \Magento\Store\Model\StoreManagerInterface::class
+        Bootstrap::getObjectManager()->get(
+            StoreManagerInterface::class
         )->reinitStores();
     }
 
@@ -54,7 +57,7 @@ public function testJoinUrlRewriteOnDefault()
      */
     public function testJoinUrlRewriteNotOnDefaultStore()
     {
-        $store = \Magento\TestFramework\Helper\Bootstrap::getObjectManager()
+        $store = Bootstrap::getObjectManager()
             ->create(\Magento\Store\Model\Store::class);
         $storeId = $store->load('second_category_store', 'code')->getId();
         $categories = $this->collection->setStoreId($storeId)->joinUrlRewrite()->addPathFilter('1/2/3');
@@ -63,4 +66,39 @@ public function testJoinUrlRewriteNotOnDefaultStore()
         $category = $categories->getFirstItem();
         $this->assertStringEndsWith('category-3-on-2.html', $category->getUrl());
     }
+
+    /**
+     * @magentoAppIsolation enabled
+     * @magentoDbIsolation enabled
+     * @magentoAppArea adminhtml
+     * @magentoDataFixture Magento/Catalog/Model/ResourceModel/_files/categories_with_products_large.php
+     */
+    public function testBulkProcessingModeIsTriggered()
+    {
+        /** @var CategoryCollection $collection */
+        $collection = $this->categoryCollectionFactory->create();
+        $collection->addAttributeToSelect('*');
+        $collection->addAttributeToFilter('name', ['like' => 'bulk_test_123%']);
+        $collection->setLoadProductCount(true);
+        $collection->load();
+
+        $this->assertGreaterThan(
+            400,
+            $collection->getSize(),
+            'Bulk limit path not triggered.'
+        );
+
+        foreach ($collection as $category) {
+            $productCount = $category->getProductCount();
+            $this->assertNotNull(
+                $productCount,
+                'ProductCount missing for category ' . $category->getId()
+            );
+            $this->assertGreaterThan(
+                0,
+                $productCount,
+                sprintf('Invalid product count for category %d.', $category->getId())
+            );
+        }
+    }
 }

dev/tests/integration/testsuite/Magento/Catalog/Model/ResourceModel/_files/categories_with_products_large.php

@@ -0,0 +1,139 @@
+<?php
+/**
+ * Copyright 2025 Adobe
+ * All Rights Reserved.
+ */
+declare(strict_types=1);
+
+use Magento\Catalog\Api\CategoryRepositoryInterface;
+use Magento\Catalog\Model\ResourceModel\Product as ProductResource;
+use Magento\Framework\App\ResourceConnection;
+use Magento\TestFramework\Helper\Bootstrap;
+use Magento\Catalog\Model\CategoryFactory;
+use Magento\Catalog\Model\ProductFactory;
+use Magento\Store\Model\StoreManagerInterface;
+
+$om = Bootstrap::getObjectManager();
+
+$storeManager     = $om->get(StoreManagerInterface::class);
+$rootCategoryId   = (int)$storeManager->getStore()->getRootCategoryId();
+
+$categoryFactory    = $om->get(CategoryFactory::class);
+$categoryRepository = $om->get(CategoryRepositoryInterface::class);
+$productFactory     = $om->get(ProductFactory::class);
+$productResource    = $om->get(ProductResource::class);
+
+$resource = $om->get(ResourceConnection::class);
+$conn = $resource->getConnection();
+$table = $resource->getTableName('catalog_category_product');
+
+$identifier       = 'bulk_test_123';
+$categoriesCount  = 401;
+
+/* products */
+$products = [];
+$totalProducts = 5;
+
+for ($i = 1; $i <= $totalProducts; $i++) {
+    $p = $productFactory->create();
+    $p->setTypeId('simple')
+        ->setAttributeSetId(4)
+        ->setSku("{$identifier}_prd_{$i}")
+        ->setName("Bulk Test Product {$i}")
+        ->setPrice(10 + $i)
+        ->setVisibility(4)
+        ->setStatus(1)
+        ->setStockData(['qty' => 10, 'is_in_stock' => 1]);
+
+    $productResource->save($p);
+    $products[] = $p->getId();
+}
+
+/* category generator + inline product assignment */
+$createCategory = function(string $name, int $parentId, bool $isLeaf = false)
+use ($categoryFactory, $categoryRepository, $products, $conn, $table) {
+
+    $cat = $categoryFactory->create();
+    $cat->setName($name)
+        ->setIsActive(true)
+        ->setIsAnchor(1)
+        ->setParentId($parentId);
+
+    $categoryRepository->save($cat);
+    $catId = (int)$cat->getId();
+
+    if ($isLeaf) {
+        $count = random_int(1, 5);
+        $sel = [];
+
+        for ($i = 0; $i < $count; $i++) {
+            $sel[] = $products[random_int(0, count($products) - 1)];
+        }
+
+        $sel = array_unique($sel);
+        $rows = [];
+
+        foreach ($sel as $pid) {
+            $rows[] = [
+                'category_id' => $catId,
+                'product_id'  => $pid,
+                'position'    => 0
+            ];
+        }
+
+        if ($rows) {
+            $conn->insertMultiple($table, $rows);
+        }
+    }
+
+    return $catId;
+};
+
+$leafCategories = [];
+$parentCategories = [];
+
+/* level 1 */
+$level1 = array_map(
+    fn($i) => $createCategory("{$identifier}_l1_{$i}", $rootCategoryId),
+    range(1, 4)
+);
+$parentCategories = array_merge($parentCategories, $level1);
+
+$lastL1 = end($level1);
+
+foreach (range(1, 10) as $i) {
+    $leafCategories[] = $createCategory("{$identifier}_l1_leaf_{$i}", $lastL1, true);
+}
+
+/* level 2 */
+$level2 = [];
+
+foreach ($level1 as $parentId) {
+
+    $createdThisLoop = [];
+
+    foreach (range(1, 13) as $i) {
+        $createdThisLoop[] = $createCategory("{$identifier}_l2_{$parentId}_{$i}", $parentId);
+    }
+
+    $level2 = array_merge($level2, $createdThisLoop);
+    $parentCategories = array_merge($parentCategories, $createdThisLoop);
+
+    foreach (range(1, 5) as $i) {
+        $leafCategories[] = $createCategory("{$identifier}_l2_{$parentId}_leaf_{$i}", $parentId, true);
+    }
+}
+
+/* level 3 leafs */
+foreach ($level2 as $parentId) {
+    $leafCategories[] = $createCategory("{$identifier}_l3_{$parentId}_leaf", $parentId, true);
+}
+
+/* extend up to target count */
+$totalCreated = count($parentCategories) + count($leafCategories);
+$missing = max(0, $categoriesCount - $totalCreated);
+
+for ($i = 1; $i <= $missing; $i++) {
+    $parentId = $parentCategories[random_int(0, count($parentCategories) - 1)];
+    $leafCategories[] = $createCategory("{$identifier}_extra_{$i}", $parentId, true);
+}