From f3262ed390f15427baad7e1470fc4ea6783ec198 Mon Sep 17 00:00:00 2001
From: Daimona Eaytoy <daimona.wiki@gmail.com>
Date: Sat, 7 Sep 2019 16:21:09 +0200
Subject: [PATCH] Add a dedicated Exception for SessionOverflow

Instead of setting a custom property and checking via isset + count.

Change-Id: I087eeb2eee414218bbd6023ad1703fde22292281
---
 includes/Setup.php                            | 25 ++++++--------
 includes/session/SessionManager.php           |  5 ++-
 includes/session/SessionOverflowException.php | 34 +++++++++++++++++++
 .../includes/session/SessionManagerTest.php   |  8 ++---
 4 files changed, 50 insertions(+), 22 deletions(-)
 create mode 100644 includes/session/SessionOverflowException.php

diff --git a/includes/Setup.php b/includes/Setup.php
index 39f0c8116f..518531aacf 100644
--- a/includes/Setup.php
+++ b/includes/Setup.php
@@ -808,22 +808,17 @@ if ( !defined( 'MW_NO_SESSION' ) && !$wgCommandLineMode ) {
 	// Initialize the session
 	try {
 		$session = MediaWiki\Session\SessionManager::getGlobalSession();
-	} catch ( OverflowException $ex ) {
-		if ( isset( $ex->sessionInfos ) && count( $ex->sessionInfos ) >= 2 ) {
-			// The exception is because the request had multiple possible
-			// sessions tied for top priority. Report this to the user.
-			$list = [];
-			foreach ( $ex->sessionInfos as $info ) {
-				$list[] = $info->getProvider()->describe( $wgContLang );
-			}
-			$list = $wgContLang->listToText( $list );
-			throw new HttpError( 400,
-				Message::newFromKey( 'sessionmanager-tie', $list )->inLanguage( $wgContLang )->plain()
-			);
+	} catch ( MediaWiki\Session\SessionOverflowException $ex ) {
+		// The exception is because the request had multiple possible
+		// sessions tied for top priority. Report this to the user.
+		$list = [];
+		foreach ( $ex->getSessionInfos() as $info ) {
+			$list[] = $info->getProvider()->describe( $wgContLang );
 		}
-
-		// Not the one we want, rethrow
-		throw $ex;
+		$list = $wgContLang->listToText( $list );
+		throw new HttpError( 400,
+			Message::newFromKey( 'sessionmanager-tie', $list )->inLanguage( $wgContLang )->plain()
+		);
 	}
 
 	if ( $session->isPersistent() ) {
diff --git a/includes/session/SessionManager.php b/includes/session/SessionManager.php
index 09cdf72f46..a3380ff82f 100644
--- a/includes/session/SessionManager.php
+++ b/includes/session/SessionManager.php
@@ -505,11 +505,10 @@ final class SessionManager implements SessionManagerInterface {
 		}
 
 		if ( count( $retInfos ) > 1 ) {
-			$ex = new \OverflowException(
+			throw new SessionOverflowException(
+				$retInfos,
 				'Multiple sessions for this request tied for top priority: ' . implode( ', ', $retInfos )
 			);
-			$ex->sessionInfos = $retInfos;
-			throw $ex;
 		}
 
 		return $retInfos ? $retInfos[0] : null;
diff --git a/includes/session/SessionOverflowException.php b/includes/session/SessionOverflowException.php
new file mode 100644
index 0000000000..2a5ed2b80a
--- /dev/null
+++ b/includes/session/SessionOverflowException.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace MediaWiki\Session;
+
+/**
+ * OverflowException specific to the SessionManager, used when the request had multiple possible
+ * sessions tied for top priority.
+ *
+ * @since 1.34
+ */
+class SessionOverflowException extends \OverflowException {
+	/** @var SessionInfo[] */
+	private $sessionInfos;
+
+	/**
+	 * @param SessionInfo[] $sessionInfos Must have at least two elements
+	 * @param string $msg
+	 * @throws \InvalidArgumentException If $sessionInfos has less than 2 elements
+	 */
+	function __construct( array $sessionInfos, $msg ) {
+		if ( count( $sessionInfos ) < 2 ) {
+			throw new \InvalidArgumentException( 'Expected at least two SessionInfo objects.' );
+		}
+		parent::__construct( $msg );
+		$this->sessionInfos = $sessionInfos;
+	}
+
+	/**
+	 * @return SessionInfo[]
+	 */
+	public function getSessionInfos() : array {
+		return $this->sessionInfos;
+	}
+}
diff --git a/tests/phpunit/includes/session/SessionManagerTest.php b/tests/phpunit/includes/session/SessionManagerTest.php
index cd0867d2ef..b2f525d741 100644
--- a/tests/phpunit/includes/session/SessionManagerTest.php
+++ b/tests/phpunit/includes/session/SessionManagerTest.php
@@ -259,14 +259,14 @@ class SessionManagerTest extends MediaWikiTestCase {
 		try {
 			$manager->getSessionForRequest( $request );
 			$this->fail( 'Expcected exception not thrown' );
-		} catch ( \OverflowException $ex ) {
+		} catch ( SessionOverflowException $ex ) {
 			$this->assertStringStartsWith(
 				'Multiple sessions for this request tied for top priority: ',
 				$ex->getMessage()
 			);
-			$this->assertCount( 2, $ex->sessionInfos );
-			$this->assertContains( $request->info1, $ex->sessionInfos );
-			$this->assertContains( $request->info2, $ex->sessionInfos );
+			$this->assertCount( 2, $ex->getSessionInfos() );
+			$this->assertContains( $request->info1, $ex->getSessionInfos() );
+			$this->assertContains( $request->info2, $ex->getSessionInfos() );
 		}
 		$this->assertFalse( $request->unpersist1 );
 		$this->assertFalse( $request->unpersist2 );
-- 
2.20.1