From 8e61ed3507040c873a159d1031295df70e4b66de Mon Sep 17 00:00:00 2001
From: Kunal Mehta <legoktm@member.fsf.org>
Date: Tue, 29 Dec 2015 17:52:11 -0800
Subject: [PATCH] registration: Prevent loading the same thing twice

Normally the registry load queue should filter out duplicates, but if
people do weird things with symlinks, throw a useful error message if
the double-loading makes it all the way to the processor.

Bug: T121493
Change-Id: I47f5cd754e5f3c91e6b83a6d0ab542404347a421
---
 includes/registration/ExtensionProcessor.php    | 17 ++++++++++++++++-
 .../registration/ExtensionProcessorTest.php     | 13 ++++++++++++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/includes/registration/ExtensionProcessor.php b/includes/registration/ExtensionProcessor.php
index cab889f5e5..074a962d5f 100644
--- a/includes/registration/ExtensionProcessor.php
+++ b/includes/registration/ExtensionProcessor.php
@@ -294,6 +294,11 @@ class ExtensionProcessor implements Processor {
 		}
 	}
 
+	/**
+	 * @param string $path
+	 * @param array $info
+	 * @throws Exception
+	 */
 	protected function extractCredits( $path, array $info ) {
 		$credits = array(
 			'path' => $path,
@@ -305,7 +310,17 @@ class ExtensionProcessor implements Processor {
 			}
 		}
 
-		$this->credits[$credits['name']] = $credits;
+		$name = $credits['name'];
+
+		// If someone is loading the same thing twice, throw
+		// a nice error (T121493)
+		if ( isset( $this->credits[$name] ) ) {
+			$firstPath = $this->credits[$name]['path'];
+			$secondPath = $credits['path'];
+			throw new Exception( "It was attempted to load $name twice, from $firstPath and $secondPath." );
+		}
+
+		$this->credits[$name] = $credits;
 	}
 
 	/**
diff --git a/tests/phpunit/includes/registration/ExtensionProcessorTest.php b/tests/phpunit/includes/registration/ExtensionProcessorTest.php
index 843f576f79..590644fc06 100644
--- a/tests/phpunit/includes/registration/ExtensionProcessorTest.php
+++ b/tests/phpunit/includes/registration/ExtensionProcessorTest.php
@@ -118,7 +118,8 @@ class ExtensionProcessorTest extends MediaWikiTestCase {
 				'_prefix' => 'eg',
 				'Bar' => 'somevalue'
 			),
-		) + self::$default;
+			'name' => 'FooBar2',
+		);
 		$processor->extractInfo( $this->dir, $info, 1 );
 		$processor->extractInfo( $this->dir, $info2, 1 );
 		$extracted = $processor->getExtractedInfo();
@@ -193,6 +194,16 @@ class ExtensionProcessorTest extends MediaWikiTestCase {
 		}
 	}
 
+	/**
+	 * @covers ExtensionProcessor::extractCredits
+	 */
+	public function testExtractCredits() {
+		$processor = new ExtensionProcessor();
+		$processor->extractInfo( $this->dir, self::$default, 1 );
+		$this->setExpectedException( 'Exception' );
+		$processor->extractInfo( $this->dir, self::$default, 1 );
+	}
+
 	/**
 	 * @covers ExtensionProcessor::extractResourceLoaderModules
 	 * @dataProvider provideExtractResourceLoaderModules
-- 
2.20.1