first commit

5 files changed, 1305 insertions, 0 deletions

diff --git a/www/wiki/includes/context/ContextSource.php b/www/wiki/includes/context/ContextSource.php
new file mode 100644
index 00000000..03fb9e2b
--- /dev/null
+++ b/www/wiki/includes/context/ContextSource.php
@@ -0,0 +1,184 @@
+<?php
+/**
+ * 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
+ *
+ * @author Happy-melon
+ * @file
+ */
+use MediaWiki\MediaWikiServices;
+
+/**
+ * The simplest way of implementing IContextSource is to hold a RequestContext as a
+ * member variable and provide accessors to it.
+ *
+ * @since 1.18
+ */
+abstract class ContextSource implements IContextSource {
+	/**
+	 * @var IContextSource
+	 */
+	private $context;
+
+	/**
+	 * Get the base IContextSource object
+	 * @since 1.18
+	 * @return IContextSource
+	 */
+	public function getContext() {
+		if ( $this->context === null ) {
+			$class = static::class;
+			wfDebug( __METHOD__ . " ($class): called and \$context is null. " .
+				"Using RequestContext::getMain() for sanity\n" );
+			$this->context = RequestContext::getMain();
+		}
+
+		return $this->context;
+	}
+
+	/**
+	 * @since 1.18
+	 * @param IContextSource $context
+	 */
+	public function setContext( IContextSource $context ) {
+		$this->context = $context;
+	}
+
+	/**
+	 * @since 1.23
+	 * @return Config
+	 */
+	public function getConfig() {
+		return $this->getContext()->getConfig();
+	}
+
+	/**
+	 * @since 1.18
+	 * @return WebRequest
+	 */
+	public function getRequest() {
+		return $this->getContext()->getRequest();
+	}
+
+	/**
+	 * @since 1.18
+	 * @return Title|null
+	 */
+	public function getTitle() {
+		return $this->getContext()->getTitle();
+	}
+
+	/**
+	 * Check whether a WikiPage object can be get with getWikiPage().
+	 * Callers should expect that an exception is thrown from getWikiPage()
+	 * if this method returns false.
+	 *
+	 * @since 1.19
+	 * @return bool
+	 */
+	public function canUseWikiPage() {
+		return $this->getContext()->canUseWikiPage();
+	}
+
+	/**
+	 * Get the WikiPage object.
+	 * May throw an exception if there's no Title object set or the Title object
+	 * belongs to a special namespace that doesn't have WikiPage, so use first
+	 * canUseWikiPage() to check whether this method can be called safely.
+	 *
+	 * @since 1.19
+	 * @return WikiPage
+	 */
+	public function getWikiPage() {
+		return $this->getContext()->getWikiPage();
+	}
+
+	/**
+	 * @since 1.18
+	 * @return OutputPage
+	 */
+	public function getOutput() {
+		return $this->getContext()->getOutput();
+	}
+
+	/**
+	 * @since 1.18
+	 * @return User
+	 */
+	public function getUser() {
+		return $this->getContext()->getUser();
+	}
+
+	/**
+	 * @since 1.19
+	 * @return Language
+	 */
+	public function getLanguage() {
+		return $this->getContext()->getLanguage();
+	}
+
+	/**
+	 * @since 1.18
+	 * @return Skin
+	 */
+	public function getSkin() {
+		return $this->getContext()->getSkin();
+	}
+
+	/**
+	 * @since 1.27
+	 * @return Timing
+	 */
+	public function getTiming() {
+		return $this->getContext()->getTiming();
+	}
+
+	/**
+	 * @deprecated since 1.27 use a StatsdDataFactory from MediaWikiServices (preferably injected)
+	 *
+	 * @since 1.25
+	 * @return IBufferingStatsdDataFactory
+	 */
+	public function getStats() {
+		return MediaWikiServices::getInstance()->getStatsdDataFactory();
+	}
+
+	/**
+	 * Get a Message object with context set
+	 * Parameters are the same as wfMessage()
+	 *
+	 * @since 1.18
+	 * @param string|string[]|MessageSpecifier $key Message key, or array of keys,
+	 *   or a MessageSpecifier.
+	 * @param mixed $args,...
+	 * @return Message
+	 */
+	public function msg( $key /* $args */ ) {
+		$args = func_get_args();
+
+		return call_user_func_array( [ $this->getContext(), 'msg' ], $args );
+	}
+
+	/**
+	 * Export the resolved user IP, HTTP headers, user ID, and session ID.
+	 * The result will be reasonably sized to allow for serialization.
+	 *
+	 * @return array
+	 * @since 1.21
+	 */
+	public function exportSession() {
+		return $this->getContext()->exportSession();
+	}
+}
diff --git a/www/wiki/includes/context/DerivativeContext.php b/www/wiki/includes/context/DerivativeContext.php
new file mode 100644
index 00000000..f7a1815d
--- /dev/null
+++ b/www/wiki/includes/context/DerivativeContext.php
@@ -0,0 +1,301 @@
+<?php
+/**
+ * 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
+ *
+ * @author Daniel Friesen
+ * @file
+ */
+use MediaWiki\MediaWikiServices;
+
+/**
+ * An IContextSource implementation which will inherit context from another source
+ * but allow individual pieces of context to be changed locally
+ * eg: A ContextSource that can inherit from the main RequestContext but have
+ *     a different Title instance set on it.
+ * @since 1.19
+ */
+class DerivativeContext extends ContextSource implements MutableContext {
+	/**
+	 * @var WebRequest
+	 */
+	private $request;
+
+	/**
+	 * @var Title
+	 */
+	private $title;
+
+	/**
+	 * @var WikiPage
+	 */
+	private $wikipage;
+
+	/**
+	 * @var OutputPage
+	 */
+	private $output;
+
+	/**
+	 * @var User
+	 */
+	private $user;
+
+	/**
+	 * @var Language
+	 */
+	private $lang;
+
+	/**
+	 * @var Skin
+	 */
+	private $skin;
+
+	/**
+	 * @var Config
+	 */
+	private $config;
+
+	/**
+	 * @var Timing
+	 */
+	private $timing;
+
+	/**
+	 * @param IContextSource $context Context to inherit from
+	 */
+	public function __construct( IContextSource $context ) {
+		$this->setContext( $context );
+	}
+
+	/**
+	 * @param Config $config
+	 */
+	public function setConfig( Config $config ) {
+		$this->config = $config;
+	}
+
+	/**
+	 * @return Config
+	 */
+	public function getConfig() {
+		if ( !is_null( $this->config ) ) {
+			return $this->config;
+		} else {
+			return $this->getContext()->getConfig();
+		}
+	}
+
+	/**
+	 * @deprecated since 1.27 use a StatsdDataFactory from MediaWikiServices (preferably injected)
+	 *
+	 * @return IBufferingStatsdDataFactory
+	 */
+	public function getStats() {
+		return MediaWikiServices::getInstance()->getStatsdDataFactory();
+	}
+
+	/**
+	 * @return Timing
+	 */
+	public function getTiming() {
+		if ( !is_null( $this->timing ) ) {
+			return $this->timing;
+		} else {
+			return $this->getContext()->getTiming();
+		}
+	}
+
+	/**
+	 * @param WebRequest $request
+	 */
+	public function setRequest( WebRequest $request ) {
+		$this->request = $request;
+	}
+
+	/**
+	 * @return WebRequest
+	 */
+	public function getRequest() {
+		if ( !is_null( $this->request ) ) {
+			return $this->request;
+		} else {
+			return $this->getContext()->getRequest();
+		}
+	}
+
+	/**
+	 * @param Title $title
+	 */
+	public function setTitle( Title $title ) {
+		$this->title = $title;
+	}
+
+	/**
+	 * @return Title|null
+	 */
+	public function getTitle() {
+		if ( !is_null( $this->title ) ) {
+			return $this->title;
+		} else {
+			return $this->getContext()->getTitle();
+		}
+	}
+
+	/**
+	 * Check whether a WikiPage object can be get with getWikiPage().
+	 * Callers should expect that an exception is thrown from getWikiPage()
+	 * if this method returns false.
+	 *
+	 * @since 1.19
+	 * @return bool
+	 */
+	public function canUseWikiPage() {
+		if ( $this->wikipage !== null ) {
+			return true;
+		} elseif ( $this->title !== null ) {
+			return $this->title->canExist();
+		} else {
+			return $this->getContext()->canUseWikiPage();
+		}
+	}
+
+	/**
+	 * @since 1.19
+	 * @param WikiPage $wikiPage
+	 */
+	public function setWikiPage( WikiPage $wikiPage ) {
+		$this->wikipage = $wikiPage;
+	}
+
+	/**
+	 * Get the WikiPage object.
+	 * May throw an exception if there's no Title object set or the Title object
+	 * belongs to a special namespace that doesn't have WikiPage, so use first
+	 * canUseWikiPage() to check whether this method can be called safely.
+	 *
+	 * @since 1.19
+	 * @return WikiPage
+	 */
+	public function getWikiPage() {
+		if ( !is_null( $this->wikipage ) ) {
+			return $this->wikipage;
+		} else {
+			return $this->getContext()->getWikiPage();
+		}
+	}
+
+	/**
+	 * @param OutputPage $output
+	 */
+	public function setOutput( OutputPage $output ) {
+		$this->output = $output;
+	}
+
+	/**
+	 * @return OutputPage
+	 */
+	public function getOutput() {
+		if ( !is_null( $this->output ) ) {
+			return $this->output;
+		} else {
+			return $this->getContext()->getOutput();
+		}
+	}
+
+	/**
+	 * @param User $user
+	 */
+	public function setUser( User $user ) {
+		$this->user = $user;
+	}
+
+	/**
+	 * @return User
+	 */
+	public function getUser() {
+		if ( !is_null( $this->user ) ) {
+			return $this->user;
+		} else {
+			return $this->getContext()->getUser();
+		}
+	}
+
+	/**
+	 * @param Language|string $language Language instance or language code
+	 * @throws MWException
+	 * @since 1.19
+	 */
+	public function setLanguage( $language ) {
+		if ( $language instanceof Language ) {
+			$this->lang = $language;
+		} elseif ( is_string( $language ) ) {
+			$language = RequestContext::sanitizeLangCode( $language );
+			$obj = Language::factory( $language );
+			$this->lang = $obj;
+		} else {
+			throw new MWException( __METHOD__ . " was passed an invalid type of data." );
+		}
+	}
+
+	/**
+	 * @return Language
+	 * @since 1.19
+	 */
+	public function getLanguage() {
+		if ( !is_null( $this->lang ) ) {
+			return $this->lang;
+		} else {
+			return $this->getContext()->getLanguage();
+		}
+	}
+
+	/**
+	 * @param Skin $skin
+	 */
+	public function setSkin( Skin $skin ) {
+		$this->skin = clone $skin;
+		$this->skin->setContext( $this );
+	}
+
+	/**
+	 * @return Skin
+	 */
+	public function getSkin() {
+		if ( !is_null( $this->skin ) ) {
+			return $this->skin;
+		} else {
+			return $this->getContext()->getSkin();
+		}
+	}
+
+	/**
+	 * Get a message using the current context.
+	 *
+	 * This can't just inherit from ContextSource, since then
+	 * it would set only the original context, and not take
+	 * into account any changes.
+	 *
+	 * @param string|string[]|MessageSpecifier $key Message key, or array of keys,
+	 *   or a MessageSpecifier.
+	 * @param mixed $args,... Arguments to wfMessage
+	 * @return Message
+	 */
+	public function msg( $key ) {
+		$args = func_get_args();
+
+		return call_user_func_array( 'wfMessage', $args )->setContext( $this );
+	}
+}
diff --git a/www/wiki/includes/context/IContextSource.php b/www/wiki/includes/context/IContextSource.php
new file mode 100644
index 00000000..6e48e1eb
--- /dev/null
+++ b/www/wiki/includes/context/IContextSource.php
@@ -0,0 +1,137 @@
+<?php
+/**
+ * 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
+ *
+ * @since 1.18
+ *
+ * @author Happy-melon
+ * @file
+ */
+
+/**
+ * Interface for objects which can provide a MediaWiki context on request
+ *
+ * Context objects contain request-dependent objects that manage the core
+ * web request/response logic for essentially all requests to MediaWiki.
+ * The contained objects include:
+ *   a) Key objects that depend (for construction/loading) on the HTTP request
+ *   b) Key objects used for response building and PHP session state control
+ *   c) Performance metric deltas accumulated from request execution
+ *   d) The site configuration object
+ * All of the objects are useful for the vast majority of MediaWiki requests.
+ * The site configuration object is included on grounds of extreme
+ * utility, even though it should not actually depend on the web request.
+ *
+ * More specifically, the scope of the context includes:
+ *   a) Objects that represent the HTTP request/response and PHP session state
+ *   b) Object representing the MediaWiki user (as determined by the HTTP request)
+ *   c) Primary MediaWiki output builder objects (OutputPage, user skin object)
+ *   d) The language object for the user/request
+ *   e) The title and wiki page objects requested via URL (if any)
+ *   f) Performance metric deltas accumulated from request execution
+ *   g) The site configuration object
+ *
+ * This class is not intended as a service-locator nor a service singleton.
+ * Objects that only depend on site configuration do not belong here (aside
+ * from Config itself). Objects that represent persistent data stores do not
+ * belong here either. Session state changes should only be propagated on
+ * shutdown by separate persistence handler objects, for example.
+ */
+interface IContextSource extends MessageLocalizer {
+
+	/**
+	 * @return WebRequest
+	 */
+	public function getRequest();
+
+	/**
+	 * @return Title|null
+	 */
+	public function getTitle();
+
+	/**
+	 * Check whether a WikiPage object can be get with getWikiPage().
+	 * Callers should expect that an exception is thrown from getWikiPage()
+	 * if this method returns false.
+	 *
+	 * @since 1.19
+	 * @return bool
+	 */
+	public function canUseWikiPage();
+
+	/**
+	 * Get the WikiPage object.
+	 * May throw an exception if there's no Title object set or the Title object
+	 * belongs to a special namespace that doesn't have WikiPage, so use first
+	 * canUseWikiPage() to check whether this method can be called safely.
+	 *
+	 * @since 1.19
+	 * @return WikiPage
+	 */
+	public function getWikiPage();
+
+	/**
+	 * @return OutputPage
+	 */
+	public function getOutput();
+
+	/**
+	 * @return User
+	 */
+	public function getUser();
+
+	/**
+	 * @return Language
+	 * @since 1.19
+	 */
+	public function getLanguage();
+
+	/**
+	 * @return Skin
+	 */
+	public function getSkin();
+
+	/**
+	 * Get the site configuration
+	 *
+	 * @since 1.23
+	 * @return Config
+	 */
+	public function getConfig();
+
+	/**
+	 * @deprecated since 1.27 use a StatsdDataFactory from MediaWikiServices (preferably injected)
+	 *
+	 * @since 1.25
+	 * @return IBufferingStatsdDataFactory
+	 */
+	public function getStats();
+
+	/**
+	 * @since 1.27
+	 * @return Timing
+	 */
+	public function getTiming();
+
+	/**
+	 * Export the resolved user IP, HTTP headers, user ID, and session ID.
+	 * The result will be reasonably sized to allow for serialization.
+	 *
+	 * @return array
+	 * @since 1.21
+	 */
+	public function exportSession();
+}
diff --git a/www/wiki/includes/context/MutableContext.php b/www/wiki/includes/context/MutableContext.php
new file mode 100644
index 00000000..56ec9601
--- /dev/null
+++ b/www/wiki/includes/context/MutableContext.php
@@ -0,0 +1,67 @@
+<?php
+/**
+ * Request-dependant objects containers.
+ *
+ * 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
+ *
+ * @since 1.26
+ *
+ * @file
+ */
+
+interface MutableContext {
+
+	/**
+	 * @param Config $config
+	 */
+	public function setConfig( Config $config );
+
+	/**
+	 * @param WebRequest $request
+	 */
+	public function setRequest( WebRequest $request );
+
+	/**
+	 * @param Title $title
+	 */
+	public function setTitle( Title $title );
+
+	/**
+	 * @param WikiPage $wikiPage
+	 */
+	public function setWikiPage( WikiPage $wikiPage );
+
+	/**
+	 * @param OutputPage $output
+	 */
+	public function setOutput( OutputPage $output );
+
+	/**
+	 * @param User $user
+	 */
+	public function setUser( User $user );
+
+	/**
+	 * @param Language|string $language Language instance or language code
+	 */
+	public function setLanguage( $language );
+
+	/**
+	 * @param Skin $skin
+	 */
+	public function setSkin( Skin $skin );
+
+}
diff --git a/www/wiki/includes/context/RequestContext.php b/www/wiki/includes/context/RequestContext.php
new file mode 100644
index 00000000..db3a7a96
--- /dev/null
+++ b/www/wiki/includes/context/RequestContext.php
@@ -0,0 +1,616 @@
+<?php
+/**
+ * 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
+ *
+ * @since 1.18
+ *
+ * @author Alexandre Emsenhuber
+ * @author Daniel Friesen
+ * @file
+ */
+
+use MediaWiki\Logger\LoggerFactory;
+use MediaWiki\MediaWikiServices;
+use Wikimedia\ScopedCallback;
+
+/**
+ * Group all the pieces relevant to the context of a request into one instance
+ */
+class RequestContext implements IContextSource, MutableContext {
+	/**
+	 * @var WebRequest
+	 */
+	private $request;
+
+	/**
+	 * @var Title
+	 */
+	private $title;
+
+	/**
+	 * @var WikiPage
+	 */
+	private $wikipage;
+
+	/**
+	 * @var OutputPage
+	 */
+	private $output;
+
+	/**
+	 * @var User
+	 */
+	private $user;
+
+	/**
+	 * @var Language
+	 */
+	private $lang;
+
+	/**
+	 * @var Skin
+	 */
+	private $skin;
+
+	/**
+	 * @var Timing
+	 */
+	private $timing;
+
+	/**
+	 * @var Config
+	 */
+	private $config;
+
+	/**
+	 * @var RequestContext
+	 */
+	private static $instance = null;
+
+	/**
+	 * @param Config $config
+	 */
+	public function setConfig( Config $config ) {
+		$this->config = $config;
+	}
+
+	/**
+	 * @return Config
+	 */
+	public function getConfig() {
+		if ( $this->config === null ) {
+			// @todo In the future, we could move this to WebStart.php so
+			// the Config object is ready for when initialization happens
+			$this->config = MediaWikiServices::getInstance()->getMainConfig();
+		}
+
+		return $this->config;
+	}
+
+	/**
+	 * @param WebRequest $request
+	 */
+	public function setRequest( WebRequest $request ) {
+		$this->request = $request;
+	}
+
+	/**
+	 * @return WebRequest
+	 */
+	public function getRequest() {
+		if ( $this->request === null ) {
+			global $wgCommandLineMode;
+			// create the WebRequest object on the fly
+			if ( $wgCommandLineMode ) {
+				$this->request = new FauxRequest( [] );
+			} else {
+				$this->request = new WebRequest();
+			}
+		}
+
+		return $this->request;
+	}
+
+	/**
+	 * @deprecated since 1.27 use a StatsdDataFactory from MediaWikiServices (preferably injected)
+	 *
+	 * @return IBufferingStatsdDataFactory
+	 */
+	public function getStats() {
+		return MediaWikiServices::getInstance()->getStatsdDataFactory();
+	}
+
+	/**
+	 * @return Timing
+	 */
+	public function getTiming() {
+		if ( $this->timing === null ) {
+			$this->timing = new Timing( [
+				'logger' => LoggerFactory::getInstance( 'Timing' )
+			] );
+		}
+		return $this->timing;
+	}
+
+	/**
+	 * @param Title|null $title
+	 */
+	public function setTitle( Title $title = null ) {
+		$this->title = $title;
+		// Erase the WikiPage so a new one with the new title gets created.
+		$this->wikipage = null;
+	}
+
+	/**
+	 * @return Title|null
+	 */
+	public function getTitle() {
+		if ( $this->title === null ) {
+			global $wgTitle; # fallback to $wg till we can improve this
+			$this->title = $wgTitle;
+			wfDebugLog(
+				'GlobalTitleFail',
+				__METHOD__ . ' called by ' . wfGetAllCallers( 5 ) . ' with no title set.'
+			);
+		}
+
+		return $this->title;
+	}
+
+	/**
+	 * Check, if a Title object is set
+	 *
+	 * @since 1.25
+	 * @return bool
+	 */
+	public function hasTitle() {
+		return $this->title !== null;
+	}
+
+	/**
+	 * Check whether a WikiPage object can be get with getWikiPage().
+	 * Callers should expect that an exception is thrown from getWikiPage()
+	 * if this method returns false.
+	 *
+	 * @since 1.19
+	 * @return bool
+	 */
+	public function canUseWikiPage() {
+		if ( $this->wikipage ) {
+			// If there's a WikiPage object set, we can for sure get it
+			return true;
+		}
+		// Only pages with legitimate titles can have WikiPages.
+		// That usually means pages in non-virtual namespaces.
+		$title = $this->getTitle();
+		return $title ? $title->canExist() : false;
+	}
+
+	/**
+	 * @since 1.19
+	 * @param WikiPage $wikiPage
+	 */
+	public function setWikiPage( WikiPage $wikiPage ) {
+		$pageTitle = $wikiPage->getTitle();
+		if ( !$this->hasTitle() || !$pageTitle->equals( $this->getTitle() ) ) {
+			$this->setTitle( $pageTitle );
+		}
+		// Defer this to the end since setTitle sets it to null.
+		$this->wikipage = $wikiPage;
+	}
+
+	/**
+	 * Get the WikiPage object.
+	 * May throw an exception if there's no Title object set or the Title object
+	 * belongs to a special namespace that doesn't have WikiPage, so use first
+	 * canUseWikiPage() to check whether this method can be called safely.
+	 *
+	 * @since 1.19
+	 * @throws MWException
+	 * @return WikiPage
+	 */
+	public function getWikiPage() {
+		if ( $this->wikipage === null ) {
+			$title = $this->getTitle();
+			if ( $title === null ) {
+				throw new MWException( __METHOD__ . ' called without Title object set' );
+			}
+			$this->wikipage = WikiPage::factory( $title );
+		}
+
+		return $this->wikipage;
+	}
+
+	/**
+	 * @param OutputPage $output
+	 */
+	public function setOutput( OutputPage $output ) {
+		$this->output = $output;
+	}
+
+	/**
+	 * @return OutputPage
+	 */
+	public function getOutput() {
+		if ( $this->output === null ) {
+			$this->output = new OutputPage( $this );
+		}
+
+		return $this->output;
+	}
+
+	/**
+	 * @param User $user
+	 */
+	public function setUser( User $user ) {
+		$this->user = $user;
+	}
+
+	/**
+	 * @return User
+	 */
+	public function getUser() {
+		if ( $this->user === null ) {
+			$this->user = User::newFromSession( $this->getRequest() );
+		}
+
+		return $this->user;
+	}
+
+	/**
+	 * Accepts a language code and ensures it's sane. Outputs a cleaned up language
+	 * code and replaces with $wgLanguageCode if not sane.
+	 * @param string $code Language code
+	 * @return string
+	 */
+	public static function sanitizeLangCode( $code ) {
+		global $wgLanguageCode;
+
+		// BCP 47 - letter case MUST NOT carry meaning
+		$code = strtolower( $code );
+
+		# Validate $code
+		if ( !$code || !Language::isValidCode( $code ) || $code === 'qqq' ) {
+			$code = $wgLanguageCode;
+		}
+
+		return $code;
+	}
+
+	/**
+	 * @param Language|string $language Language instance or language code
+	 * @throws MWException
+	 * @since 1.19
+	 */
+	public function setLanguage( $language ) {
+		if ( $language instanceof Language ) {
+			$this->lang = $language;
+		} elseif ( is_string( $language ) ) {
+			$language = self::sanitizeLangCode( $language );
+			$obj = Language::factory( $language );
+			$this->lang = $obj;
+		} else {
+			throw new MWException( __METHOD__ . " was passed an invalid type of data." );
+		}
+	}
+
+	/**
+	 * Get the Language object.
+	 * Initialization of user or request objects can depend on this.
+	 * @return Language
+	 * @throws Exception
+	 * @since 1.19
+	 */
+	public function getLanguage() {
+		if ( isset( $this->recursion ) ) {
+			trigger_error( "Recursion detected in " . __METHOD__, E_USER_WARNING );
+			$e = new Exception;
+			wfDebugLog( 'recursion-guard', "Recursion detected:\n" . $e->getTraceAsString() );
+
+			$code = $this->getConfig()->get( 'LanguageCode' ) ?: 'en';
+			$this->lang = Language::factory( $code );
+		} elseif ( $this->lang === null ) {
+			$this->recursion = true;
+
+			global $wgContLang;
+
+			try {
+				$request = $this->getRequest();
+				$user = $this->getUser();
+
+				$code = $request->getVal( 'uselang', 'user' );
+				if ( $code === 'user' ) {
+					$code = $user->getOption( 'language' );
+				}
+				$code = self::sanitizeLangCode( $code );
+
+				Hooks::run( 'UserGetLanguageObject', [ $user, &$code, $this ] );
+
+				if ( $code === $this->getConfig()->get( 'LanguageCode' ) ) {
+					$this->lang = $wgContLang;
+				} else {
+					$obj = Language::factory( $code );
+					$this->lang = $obj;
+				}
+
+				unset( $this->recursion );
+			}
+			catch ( Exception $ex ) {
+				unset( $this->recursion );
+				throw $ex;
+			}
+		}
+
+		return $this->lang;
+	}
+
+	/**
+	 * @param Skin $skin
+	 */
+	public function setSkin( Skin $skin ) {
+		$this->skin = clone $skin;
+		$this->skin->setContext( $this );
+	}
+
+	/**
+	 * @return Skin
+	 */
+	public function getSkin() {
+		if ( $this->skin === null ) {
+			$skin = null;
+			Hooks::run( 'RequestContextCreateSkin', [ $this, &$skin ] );
+			$factory = SkinFactory::getDefaultInstance();
+
+			// If the hook worked try to set a skin from it
+			if ( $skin instanceof Skin ) {
+				$this->skin = $skin;
+			} elseif ( is_string( $skin ) ) {
+				// Normalize the key, just in case the hook did something weird.
+				$normalized = Skin::normalizeKey( $skin );
+				$this->skin = $factory->makeSkin( $normalized );
+			}
+
+			// If this is still null (the hook didn't run or didn't work)
+			// then go through the normal processing to load a skin
+			if ( $this->skin === null ) {
+				if ( !in_array( 'skin', $this->getConfig()->get( 'HiddenPrefs' ) ) ) {
+					# get the user skin
+					$userSkin = $this->getUser()->getOption( 'skin' );
+					$userSkin = $this->getRequest()->getVal( 'useskin', $userSkin );
+				} else {
+					# if we're not allowing users to override, then use the default
+					$userSkin = $this->getConfig()->get( 'DefaultSkin' );
+				}
+
+				// Normalize the key in case the user is passing gibberish
+				// or has old preferences (T71566).
+				$normalized = Skin::normalizeKey( $userSkin );
+
+				// Skin::normalizeKey will also validate it, so
+				// this won't throw an exception
+				$this->skin = $factory->makeSkin( $normalized );
+			}
+
+			// After all that set a context on whatever skin got created
+			$this->skin->setContext( $this );
+		}
+
+		return $this->skin;
+	}
+
+	/**
+	 * Get a Message object with context set
+	 * Parameters are the same as wfMessage()
+	 *
+	 * @param string|string[]|MessageSpecifier $key Message key, or array of keys,
+	 *   or a MessageSpecifier.
+	 * @param mixed $args,...
+	 * @return Message
+	 */
+	public function msg( $key ) {
+		$args = func_get_args();
+
+		return call_user_func_array( 'wfMessage', $args )->setContext( $this );
+	}
+
+	/**
+	 * Get the RequestContext object associated with the main request
+	 *
+	 * @return RequestContext
+	 */
+	public static function getMain() {
+		if ( self::$instance === null ) {
+			self::$instance = new self;
+		}
+
+		return self::$instance;
+	}
+
+	/**
+	 * Get the RequestContext object associated with the main request
+	 * and gives a warning to the log, to find places, where a context maybe is missing.
+	 *
+	 * @param string $func
+	 * @return RequestContext
+	 * @since 1.24
+	 */
+	public static function getMainAndWarn( $func = __METHOD__ ) {
+		wfDebug( $func . ' called without context. ' .
+			"Using RequestContext::getMain() for sanity\n" );
+
+		return self::getMain();
+	}
+
+	/**
+	 * Resets singleton returned by getMain(). Should be called only from unit tests.
+	 */
+	public static function resetMain() {
+		if ( !( defined( 'MW_PHPUNIT_TEST' ) || defined( 'MW_PARSER_TEST' ) ) ) {
+			throw new MWException( __METHOD__ . '() should be called only from unit tests!' );
+		}
+		self::$instance = null;
+	}
+
+	/**
+	 * Export the resolved user IP, HTTP headers, user ID, and session ID.
+	 * The result will be reasonably sized to allow for serialization.
+	 *
+	 * @return array
+	 * @since 1.21
+	 */
+	public function exportSession() {
+		$session = MediaWiki\Session\SessionManager::getGlobalSession();
+		return [
+			'ip' => $this->getRequest()->getIP(),
+			'headers' => $this->getRequest()->getAllHeaders(),
+			'sessionId' => $session->isPersistent() ? $session->getId() : '',
+			'userId' => $this->getUser()->getId()
+		];
+	}
+
+	/**
+	 * Import an client IP address, HTTP headers, user ID, and session ID
+	 *
+	 * This sets the current session, $wgUser, and $wgRequest from $params.
+	 * Once the return value falls out of scope, the old context is restored.
+	 * This method should only be called in contexts where there is no session
+	 * ID or end user receiving the response (CLI or HTTP job runners). This
+	 * is partly enforced, and is done so to avoid leaking cookies if certain
+	 * error conditions arise.
+	 *
+	 * This is useful when background scripts inherit context when acting on
+	 * behalf of a user. In general the 'sessionId' parameter should be set
+	 * to an empty string unless session importing is *truly* needed. This
+	 * feature is somewhat deprecated.
+	 *
+	 * @note suhosin.session.encrypt may interfere with this method.
+	 *
+	 * @param array $params Result of RequestContext::exportSession()
+	 * @return ScopedCallback
+	 * @throws MWException
+	 * @since 1.21
+	 */
+	public static function importScopedSession( array $params ) {
+		if ( strlen( $params['sessionId'] ) &&
+			MediaWiki\Session\SessionManager::getGlobalSession()->isPersistent()
+		) {
+			// Sanity check to avoid sending random cookies for the wrong users.
+			// This method should only called by CLI scripts or by HTTP job runners.
+			throw new MWException( "Sessions can only be imported when none is active." );
+		} elseif ( !IP::isValid( $params['ip'] ) ) {
+			throw new MWException( "Invalid client IP address '{$params['ip']}'." );
+		}
+
+		if ( $params['userId'] ) { // logged-in user
+			$user = User::newFromId( $params['userId'] );
+			$user->load();
+			if ( !$user->getId() ) {
+				throw new MWException( "No user with ID '{$params['userId']}'." );
+			}
+		} else { // anon user
+			$user = User::newFromName( $params['ip'], false );
+		}
+
+		$importSessionFunc = function ( User $user, array $params ) {
+			global $wgRequest, $wgUser;
+
+			$context = RequestContext::getMain();
+
+			// Commit and close any current session
+			if ( MediaWiki\Session\PHPSessionHandler::isEnabled() ) {
+				session_write_close(); // persist
+				session_id( '' ); // detach
+				$_SESSION = []; // clear in-memory array
+			}
+
+			// Get new session, if applicable
+			$session = null;
+			if ( strlen( $params['sessionId'] ) ) { // don't make a new random ID
+				$manager = MediaWiki\Session\SessionManager::singleton();
+				$session = $manager->getSessionById( $params['sessionId'], true )
+					?: $manager->getEmptySession();
+			}
+
+			// Remove any user IP or agent information, and attach the request
+			// with the new session.
+			$context->setRequest( new FauxRequest( [], false, $session ) );
+			$wgRequest = $context->getRequest(); // b/c
+
+			// Now that all private information is detached from the user, it should
+			// be safe to load the new user. If errors occur or an exception is thrown
+			// and caught (leaving the main context in a mixed state), there is no risk
+			// of the User object being attached to the wrong IP, headers, or session.
+			$context->setUser( $user );
+			$wgUser = $context->getUser(); // b/c
+			if ( $session && MediaWiki\Session\PHPSessionHandler::isEnabled() ) {
+				session_id( $session->getId() );
+				Wikimedia\quietCall( 'session_start' );
+			}
+			$request = new FauxRequest( [], false, $session );
+			$request->setIP( $params['ip'] );
+			foreach ( $params['headers'] as $name => $value ) {
+				$request->setHeader( $name, $value );
+			}
+			// Set the current context to use the new WebRequest
+			$context->setRequest( $request );
+			$wgRequest = $context->getRequest(); // b/c
+		};
+
+		// Stash the old session and load in the new one
+		$oUser = self::getMain()->getUser();
+		$oParams = self::getMain()->exportSession();
+		$oRequest = self::getMain()->getRequest();
+		$importSessionFunc( $user, $params );
+
+		// Set callback to save and close the new session and reload the old one
+		return new ScopedCallback(
+			function () use ( $importSessionFunc, $oUser, $oParams, $oRequest ) {
+				global $wgRequest;
+				$importSessionFunc( $oUser, $oParams );
+				// Restore the exact previous Request object (instead of leaving FauxRequest)
+				RequestContext::getMain()->setRequest( $oRequest );
+				$wgRequest = RequestContext::getMain()->getRequest(); // b/c
+			}
+		);
+	}
+
+	/**
+	 * Create a new extraneous context. The context is filled with information
+	 * external to the current session.
+	 * - Title is specified by argument
+	 * - Request is a FauxRequest, or a FauxRequest can be specified by argument
+	 * - User is an anonymous user, for separation IPv4 localhost is used
+	 * - Language will be based on the anonymous user and request, may be content
+	 *   language or a uselang param in the fauxrequest data may change the lang
+	 * - Skin will be based on the anonymous user, should be the wiki's default skin
+	 *
+	 * @param Title $title Title to use for the extraneous request
+	 * @param WebRequest|array $request A WebRequest or data to use for a FauxRequest
+	 * @return RequestContext
+	 */
+	public static function newExtraneousContext( Title $title, $request = [] ) {
+		$context = new self;
+		$context->setTitle( $title );
+		if ( $request instanceof WebRequest ) {
+			$context->setRequest( $request );
+		} else {
+			$context->setRequest( new FauxRequest( $request ) );
+		}
+		$context->user = User::newFromName( '127.0.0.1', false );
+
+		return $context;
+	}
+}