From e4fc1ffec346a3b29622761362f866b1248b94bd Mon Sep 17 00:00:00 2001
From: daniel <daniel.kinzler@wikimedia.de>
Date: Wed, 10 May 2017 18:00:38 +0200
Subject: [PATCH] Allow namespaces defined in extension.json to be overwritten
 locally.

This allows extension namespaces to be assigned a custom ID, e.g. in case
the namespace pre-defined by the extension is already taken on the local
wiki.

This is done by defining the respective namespace constant in
LocalSettings.php.

Bug: T160462
Change-Id: If648d6e218847e6632d643ea724cd3da3945db70
---
 includes/registration/ExtensionProcessor.php  | 11 +++-
 .../registration/ExtensionProcessorTest.php   | 52 +++++++++++++++++++
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/includes/registration/ExtensionProcessor.php b/includes/registration/ExtensionProcessor.php
index 1212f9972c..feffac16ca 100644
--- a/includes/registration/ExtensionProcessor.php
+++ b/includes/registration/ExtensionProcessor.php
@@ -241,8 +241,15 @@ class ExtensionProcessor implements Processor {
 	protected function extractNamespaces( array $info ) {
 		if ( isset( $info['namespaces'] ) ) {
 			foreach ( $info['namespaces'] as $ns ) {
-				$id = $ns['id'];
-				$this->defines[$ns['constant']] = $id;
+				if ( defined( $ns['constant'] ) ) {
+					// If the namespace constant is already defined, use it.
+					// This allows namespace IDs to be overwritten locally.
+					$id = constant( $ns['constant'] );
+				} else {
+					$id = $ns['id'];
+					$this->defines[ $ns['constant'] ] = $id;
+				}
+
 				if ( !( isset( $ns['conditional'] ) && $ns['conditional'] ) ) {
 					// If it is not conditional, register it
 					$this->attributes['ExtensionNamespaces'][$id] = $ns['name'];
diff --git a/tests/phpunit/includes/registration/ExtensionProcessorTest.php b/tests/phpunit/includes/registration/ExtensionProcessorTest.php
index d15725d2a4..5ecf103b4e 100644
--- a/tests/phpunit/includes/registration/ExtensionProcessorTest.php
+++ b/tests/phpunit/includes/registration/ExtensionProcessorTest.php
@@ -40,6 +40,58 @@ class ExtensionProcessorTest extends MediaWikiTestCase {
 		$this->assertArrayNotHasKey( 'AutoloadClasses', $attributes );
 	}
 
+	/**
+	 * @covers ExtensionProcessor::extractInfo
+	 */
+	public function testExtractInfo_namespaces() {
+		// Test that namespace IDs can be overwritten
+		if ( !defined( 'MW_EXTENSION_PROCESSOR_TEST_EXTRACT_INFO_X' ) ) {
+			define( 'MW_EXTENSION_PROCESSOR_TEST_EXTRACT_INFO_X', 123456 );
+		}
+
+		$processor = new ExtensionProcessor();
+		$processor->extractInfo( $this->dir, self::$default + [
+			'namespaces' => [
+				[
+					'id' => 332200,
+					'constant' => 'MW_EXTENSION_PROCESSOR_TEST_EXTRACT_INFO_A',
+					'name' => 'Test_A',
+					'content' => 'TestModel'
+				],
+				[ // Test_X will use ID 123456 not 334400
+					'id' => 334400,
+					'constant' => 'MW_EXTENSION_PROCESSOR_TEST_EXTRACT_INFO_X',
+					'name' => 'Test_X',
+					'content' => 'TestModel'
+				],
+			]
+		], 1 );
+
+		$extracted = $processor->getExtractedInfo();
+
+		$this->assertArrayHasKey(
+			'MW_EXTENSION_PROCESSOR_TEST_EXTRACT_INFO_A',
+			$extracted['defines']
+		);
+		$this->assertArrayNotHasKey(
+			'MW_EXTENSION_PROCESSOR_TEST_EXTRACT_INFO_X',
+			$extracted['defines']
+		);
+
+		$this->assertSame(
+			$extracted['defines']['MW_EXTENSION_PROCESSOR_TEST_EXTRACT_INFO_A'],
+			332200
+		);
+
+		$this->assertArrayHasKey( 'ExtensionNamespaces', $extracted['attributes'] );
+		$this->assertArrayHasKey( 123456, $extracted['attributes']['ExtensionNamespaces'] );
+		$this->assertArrayHasKey( 332200, $extracted['attributes']['ExtensionNamespaces'] );
+		$this->assertArrayNotHasKey( 334400, $extracted['attributes']['ExtensionNamespaces'] );
+
+		$this->assertSame( 'Test_X', $extracted['attributes']['ExtensionNamespaces'][123456] );
+		$this->assertSame( 'Test_A', $extracted['attributes']['ExtensionNamespaces'][332200] );
+	}
+
 	public static function provideRegisterHooks() {
 		$merge = [ ExtensionRegistry::MERGE_STRATEGY => 'array_merge_recursive' ];
 		// Format:
-- 
2.20.1