From 7d8ce1e287ce4b59639a6820a8d5b774a5117d84 Mon Sep 17 00:00:00 2001
From: Peter Wilson <peterwilsoncc@git.wordpress.org>
Date: Mon, 21 Jan 2019 04:26:33 +0000
Subject: [PATCH] Options: Avoid unnecessary DB calls when updating network
 options.

Adds a `maybe_serialize()` comparison for the old and new values in `update_network_option()` to avoid unnecessary database writes when options contain identical objects.

Props bor0.
Fixes #44956.



git-svn-id: https://develop.svn.wordpress.org/trunk@44662 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/option.php                   | 11 +++++-
 tests/phpunit/tests/option/networkOption.php | 36 ++++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/option.php b/src/wp-includes/option.php
index 1c0d88225e..21a09bbd51 100644
--- a/src/wp-includes/option.php
+++ b/src/wp-includes/option.php
@@ -1583,7 +1583,16 @@ function update_network_option( $network_id, $option, $value ) {
 	 */
 	$value = apply_filters( "pre_update_site_option_{$option}", $value, $old_value, $option, $network_id );
 
-	if ( $value === $old_value ) {
+	/*
+	 * If the new and old values are the same, no need to update.
+	 *
+	 * Unserialized values will be adequate in most cases. If the unserialized
+	 * data differs, the (maybe) serialized data is checked to avoid
+	 * unnecessary database calls for otherwise identical object instances.
+	 *
+	 * See https://core.trac.wordpress.org/ticket/44956
+	 */
+	if ( $value === $old_value || maybe_serialize( $value ) === maybe_serialize( $old_value ) ) {
 		return false;
 	}
 
diff --git a/tests/phpunit/tests/option/networkOption.php b/tests/phpunit/tests/option/networkOption.php
index 637ff5732a..244ea43898 100644
--- a/tests/phpunit/tests/option/networkOption.php
+++ b/tests/phpunit/tests/option/networkOption.php
@@ -169,4 +169,40 @@ class Tests_Option_NetworkOption extends WP_UnitTestCase {
 
 		$this->assertSame( array( 'this_does_not_exist' => true ), $cache );
 	}
+
+	/**
+	 * Ensure updating network options containing an object do not result in unneeded database calls.
+	 *
+	 * @ticket 44956
+	 */
+	public function test_update_network_option_array_with_object() {
+		$array_w_object = array(
+			'url'       => 'http://src.wordpress-develop.dev/wp-content/uploads/2016/10/cropped-Blurry-Lights.jpg',
+			'meta_data' => (object) array(
+				'attachment_id' => 292,
+				'height'        => 708,
+				'width'         => 1260,
+			),
+		);
+
+		$array_w_object_2 = array(
+			'url'       => 'http://src.wordpress-develop.dev/wp-content/uploads/2016/10/cropped-Blurry-Lights.jpg',
+			'meta_data' => (object) array(
+				'attachment_id' => 292,
+				'height'        => 708,
+				'width'         => 1260,
+			),
+		);
+
+		// Add the option, it did not exist before this.
+		add_network_option( null, 'array_w_object', $array_w_object );
+
+		$num_queries_pre_update = get_num_queries();
+
+		// Update the option using the same array with an object for the value.
+		$this->assertFalse( update_network_option( null, 'array_w_object', $array_w_object_2 ) );
+
+		// Check that no new database queries were performed.
+		$this->assertEquals( $num_queries_pre_update, get_num_queries() );
+	}
 }