From 4d413376b96b2a377f7a5206f63742743bd3f809 Mon Sep 17 00:00:00 2001
From: Cindy Cicalese <cindom@gmail.com>
Date: Sun, 23 May 2021 13:29:35 -0400
Subject: [PATCH] Fix array order for array_replace_recursive merge strategy

Prior to this change, if a configuration array is defined
in extension.json, array elements cannot be overridden by
setting values in the corresponding configuration variable,
as intended by the array_replace_recursive merge strategy.
This is because the order of the arrays in the
array_replace_recursive() function call need to be
reversed.

Bug: T283464
Change-Id: I55561232a994f745c5f3cd8394674b18c0529d13
---
 includes/registration/ExtensionRegistry.php            |  2 +-
 .../includes/registration/ExtensionRegistryTest.php    | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/includes/registration/ExtensionRegistry.php b/includes/registration/ExtensionRegistry.php
index 5fd79242f48..de4ad081a5e 100644
--- a/includes/registration/ExtensionRegistry.php
+++ b/includes/registration/ExtensionRegistry.php
@@ -494,7 +494,7 @@ class ExtensionRegistry {
 					$GLOBALS[$key] = array_merge_recursive( $GLOBALS[$key], $val );
 					break;
 				case 'array_replace_recursive':
-					$GLOBALS[$key] = array_replace_recursive( $GLOBALS[$key], $val );
+					$GLOBALS[$key] = array_replace_recursive( $val, $GLOBALS[$key] );
 					break;
 				case 'array_plus_2d':
 					$GLOBALS[$key] = wfArrayPlus2d( $GLOBALS[$key], $val );
diff --git a/tests/phpunit/includes/registration/ExtensionRegistryTest.php b/tests/phpunit/includes/registration/ExtensionRegistryTest.php
index 58064186f1b..a39088e3334 100644
--- a/tests/phpunit/includes/registration/ExtensionRegistryTest.php
+++ b/tests/phpunit/includes/registration/ExtensionRegistryTest.php
@@ -361,17 +361,17 @@ class ExtensionRegistryTest extends MediaWikiIntegrationTestCase {
 						'JsonZeroConfig' => [
 							'namespace' => 480,
 							'nsName' => 'Zero',
-							'isLocal' => true,
+							'isLocal' => false,
+							'remote' => [
+								'username' => 'foo',
+							],
 						],
 					],
 				],
 				[
 					'mwtestJsonConfigs' => [
 						'JsonZeroConfig' => [
-							'isLocal' => false,
-							'remote' => [
-								'username' => 'foo',
-							],
+							'isLocal' => true,
 						],
 						ExtensionRegistry::MERGE_STRATEGY => 'array_replace_recursive',
 					],