Cherry pick 37313 into release/7.6 (#37357)

* Overwrite clone method to prevent duplicate data when saving a clone. (#37313)

* Add unit test to simulate duplicate meta insert.

* Overwrite clone method to prevent duplicate datq when saving a clone.

* Add changelog.

* Coding standard fixes.

* Fix phpcs

---------

Co-authored-by: Jorge A. Torres <jorge.torres@automattic.com>

* Prep for cherry pick 37313

---------

Co-authored-by: Vedanshu Jain <vedanshu.jain.2012@gmail.com>
Co-authored-by: Jorge A. Torres <jorge.torres@automattic.com>
Co-authored-by: WooCommerce Bot <no-reply@woocommerce.com>

plugins/woocommerce/includes/abstracts/abstract-wc-order.php

@@ -131,6 +131,17 @@ public function __construct( $order = 0 ) {
 		}
 	}
 
+	/**
+	 * This method overwrites the base class's clone method to make it a no-op. In base class WC_Data, we are unsetting the meta_id to clone.
+	 * It seems like this was done to avoid conflicting the metadata when duplicating products. However, doing that does not seems necessary for orders.
+	 * In-fact, when we do that for orders, we lose the capability to clone orders with custom meta data by caching plugins. This is because, when we clone an order object for caching, it will clone the metadata without the ID. Unfortunately, when this cached object with nulled meta ID is retreived, WC_Data will consider it as a new meta and will insert it as a new meta-data causing duplicates.
+	 *
+	 * Eventually, we should move away from overwriting the __clone method in base class itself, since it's easily possible to still duplicate the product without having to hook into the __clone method.
+	 *
+	 * @since 7.6.0
+	 */
+	public function __clone() {}
+
 	/**
 	 * Get internal type.
 	 *

plugins/woocommerce/readme.txt

@@ -168,6 +168,7 @@ WooCommerce comes with some sample data you can use to see how products look; im
 **WooCommerce**
 
 * Fix - When order meta data is saved via HPOS, it should be backfilled to the CPT data store. [#36593](https://github.com/woocommerce/woocommerce/pull/36593)
+* Fix - Overwrite clone method to prevent duplicate datq when saving a clone. [#37313](https://github.com/woocommerce/woocommerce/pull/37313)
 * Fix - Add default button padding to TT2 stylesheet to fix some visual issues in WP 5.9 and 6.0 [#37018](https://github.com/woocommerce/woocommerce/pull/37018)
 * Fix - Added skydropx slug back to shipping partners list so that it can be installed through the shipping task [#37286](https://github.com/woocommerce/woocommerce/pull/37286)
 * Fix - Add HPOS compat for admin report functions. [#36650](https://github.com/woocommerce/woocommerce/pull/36650)

plugins/woocommerce/src/Caches/OrderCache.php

@@ -2,6 +2,7 @@
 
 namespace Automattic\WooCommerce\Caches;
 
+use Automattic\WooCommerce\Caching\CacheException;
 use Automattic\WooCommerce\Caching\ObjectCache;
 
 /**

plugins/woocommerce/tests/php/src/Caching/OrderCacheTest.php

@@ -0,0 +1,51 @@
+<?php
+
+use Automattic\WooCommerce\Caches\OrderCache;
+use Automattic\WooCommerce\Internal\DataStores\Orders\OrdersTableDataStore;
+use Automattic\WooCommerce\Utilities\OrderUtil;
+
+/**
+ * Class OrderCacheTest.
+ */
+class OrderCacheTest extends \WC_Unit_Test_Case {
+
+	/**
+	 * System under test.
+	 *
+	 * @var OrderCache
+	 */
+	private $sut;
+
+	/**
+	 * Setup test.
+	 */
+	public function setUp(): void {
+		parent::setUp();
+		$this->sut = new OrderCache();
+	}
+
+	/**
+	 * Test that the order cache does not cause duplicate data storage.
+	 */
+	public function test_meta_is_not_duplicated_when_cached() {
+		global $wpdb;
+		if ( ! OrderUtil::orders_cache_usage_is_enabled() ) {
+			// tip: add HPOS=1 env variable to run this test.
+			$this->markTestSkipped( 'HPOS based caching is not enabled.' );
+		}
+		$order = WC_Helper_Order::create_order();
+		$order->add_meta_data( 'test', 'test' );
+		$order->save_meta_data();
+
+		$order = wc_get_order( $order->get_id() );
+		$this->assertTrue( $this->sut->is_cached( $order->get_id() ), 'Order was not cached, but it was expected to be cached. Are you sure that HPOS based caching is enabled.' );
+
+		$order2 = wc_get_order( $order->get_id() );
+		$order2->save_meta_data();
+
+		$orders_meta_table = OrdersTableDataStore::get_meta_table_name();
+		$query             = $wpdb->prepare( "SELECT id FROM $orders_meta_table WHERE order_id = %d AND meta_key = %s", $order->get_id(), 'test' ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
+		$this->assertEquals( 1, count( $wpdb->get_col( $query ) ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- Already prepared query.
+	}
+
+}