From: Marius Hoch <hoo@online.de>
Date: Tue, 23 Jan 2018 18:44:28 +0000 (-0800)
Subject: ExtensionRegistry: Properly detect if a global is already set
X-Git-Tag: 1.31.0-rc.0~820
X-Git-Url: http://git.cyclocoop.org/%40spipnet%40?a=commitdiff_plain;h=cc433d1ff1dd9e196a911fcc9dd3748611b413ed;p=lhc%2Fweb%2Fwiklou.git

ExtensionRegistry: Properly detect if a global is already set

$foo = null; isset( $foo ); will yield false.

Sometimes we want to explicitly set a config to null, but ExtensionRegistry
is then overriding this variable with the default value.

This is no consistent with the old workflow:
require_once the extension and then override the setting with null.

Bug: T128661
Change-Id: I0654c9369a596e84591fcaa9643703e6b4ccf57e
---

diff --git a/includes/registration/ExtensionRegistry.php b/includes/registration/ExtensionRegistry.php
index 6308461438..ae1ab58906 100644
--- a/includes/registration/ExtensionRegistry.php
+++ b/includes/registration/ExtensionRegistry.php
@@ -291,7 +291,7 @@ class ExtensionRegistry {
 
 			// Optimistic: If the global is not set, or is an empty array, replace it entirely.
 			// Will be O(1) performance.
-			if ( !isset( $GLOBALS[$key] ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
+			if ( !array_key_exists( $key, $GLOBALS ) || ( is_array( $GLOBALS[$key] ) && !$GLOBALS[$key] ) ) {
 				$GLOBALS[$key] = $val;
 				continue;
 			}
diff --git a/tests/phpunit/includes/registration/ExtensionRegistryTest.php b/tests/phpunit/includes/registration/ExtensionRegistryTest.php
index 9b57e1c3d1..5916b4510b 100644
--- a/tests/phpunit/includes/registration/ExtensionRegistryTest.php
+++ b/tests/phpunit/includes/registration/ExtensionRegistryTest.php
@@ -287,6 +287,18 @@ class ExtensionRegistryTest extends MediaWikiTestCase {
 					],
 				],
 			],
+			[
+				'global is null before',
+				[
+					'NullGlobal' => null,
+				],
+				[
+					'NullGlobal' => 'not-null'
+				],
+				[
+					'NullGlobal' => null
+				],
+			],
 		];
 	}
 }