From 6a269d4d8df38746830b012cda5d9120f501f7d6 Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@wikimedia.org>
Date: Wed, 10 Feb 2016 21:04:28 +1100
Subject: [PATCH] Suppress SessionManager sessions in the installer

SessionManager cannot work in the installer since it depends on
ObjectCache which is just an EmptyBagOStuff and so doesn't store
anything. So, introduce a custom SessionProvider which pretends to
persist sessions but actually doesn't.

Bug: T126177
Change-Id: I13d8aa1453c519df7c19ca2f1fb052c99ade043c
---
 autoload.php                                  |  1 +
 includes/installer/Installer.php              |  9 +++
 .../installer/InstallerSessionProvider.php    | 60 +++++++++++++++++++
 3 files changed, 70 insertions(+)
 create mode 100644 includes/installer/InstallerSessionProvider.php

diff --git a/autoload.php b/autoload.php
index 0a9d80c6f1..d6e40777ff 100644
--- a/autoload.php
+++ b/autoload.php
@@ -593,6 +593,7 @@ $wgAutoloadLocalClasses = array(
 	'InstallDocFormatter' => __DIR__ . '/includes/installer/InstallDocFormatter.php',
 	'Installer' => __DIR__ . '/includes/installer/Installer.php',
 	'InstallerOverrides' => __DIR__ . '/mw-config/overrides.php',
+	'InstallerSessionProvider' => __DIR__ . '/includes/installer/InstallerSessionProvider.php',
 	'Interwiki' => __DIR__ . '/includes/interwiki/Interwiki.php',
 	'InvalidPassword' => __DIR__ . '/includes/password/InvalidPassword.php',
 	'IteratorDecorator' => __DIR__ . '/includes/utils/iterators/IteratorDecorator.php',
diff --git a/includes/installer/Installer.php b/includes/installer/Installer.php
index 40e51f0b41..0e8633ded7 100644
--- a/includes/installer/Installer.php
+++ b/includes/installer/Installer.php
@@ -1785,6 +1785,15 @@ abstract class Installer {
 
 		// Some of the environment checks make shell requests, remove limits
 		$GLOBALS['wgMaxShellMemory'] = 0;
+
+		$GLOBALS['wgSessionProviders'] = array(
+			array(
+				'class' => 'InstallerSessionProvider',
+				'args' => array( array(
+					'priority' => 1,
+				) )
+			)
+		);
 	}
 
 	/**
diff --git a/includes/installer/InstallerSessionProvider.php b/includes/installer/InstallerSessionProvider.php
new file mode 100644
index 0000000000..2b9f418590
--- /dev/null
+++ b/includes/installer/InstallerSessionProvider.php
@@ -0,0 +1,60 @@
+<?php
+/**
+ * Session provider which always provides the same session ID and doesn't
+ * persist the session. For use in the installer when ObjectCache doesn't
+ * work anyway.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Deployment
+ */
+
+use MediaWiki\Session\SessionProvider;
+use MediaWiki\Session\SessionBackend;
+use MediaWiki\Session\SessionInfo;
+
+class InstallerSessionProvider extends SessionProvider {
+	/**
+	 * Pretend there is a session, to avoid MWCryptRand overhead
+	 */
+	public function provideSessionInfo( WebRequest $request ) {
+		return new SessionInfo( 1, array(
+			'provider' => $this,
+			'id' => str_repeat( 'x', 32 ),
+		) );
+	}
+
+	/**
+	 * Yes we will treat your data with great care!
+	 */
+	public function persistsSessionId() {
+		return true;
+	}
+
+	/**
+	 * Sure, you can be whoever you want, as long as you have ID 0
+	 */
+	public function canChangeUser() {
+		return true;
+	}
+
+	public function persistSession( SessionBackend $session, WebRequest $request ) {
+	}
+
+	public function unpersistSession( WebRequest $request ) {
+	}
+}
-- 
2.20.1