Revert r86872: Breaks LiquidThreads page moves with the below failure. Threads are lost and nowhere to be found any more.

[25-Apr-2011 18:12:45] /wiki/Special:MoveThread/Thread:User_talk:Siebrand/test/One_new_message: Exception: MWNamespace::getTalk does not make any sense for given namespace -1
#0 /www/w/includes/Namespace.php(81): MWNamespace::isMethodValidFor(-1, 'MWNamespace::ge...')
#1 /www/w/includes/WatchedItem.php(73): MWNamespace::getTalk(-1)
#2 /www/w/includes/User.php(2304): WatchedItem->addWatch()
#3 /www/w/includes/actions/WatchAction.php(53): User->addWatch(Object(Title))
#4 /www/w/includes/Action.php(376): WatchAction->onView()
#5 /www/w/extensions/LiquidThreads/classes/Thread.php(115): FormlessAction->execute()
#6 /www/w/extensions/LiquidThreads/classes/Thread.php(435): Thread::create(Object(Article), Object(Article), NULL, 1, 'One new message')
#7 /www/w/extensions/LiquidThreads/classes/Thread.php(414): Thread->leaveTrace('move test', Object(Title), Object(Title))
#8 /www/w/extensions/LiquidThreads/pages/SpecialMoveThread.php(107): Thread->moveToPage(Object(Title), 'move test', true)
#9 [internal function]: SpecialMoveThread->trySubmit(Array)
#10 /www/w/includes/HTMLForm.php(279): call_user_func(Array, Array)
#11 /www/w/includes/HTMLForm.php(228): HTMLForm->trySubmit()
#12 /www/w/includes/HTMLForm.php(242): HTMLForm->tryAuthorizedSubmit()
#13 /www/w/extensions/LiquidThreads/pages/ThreadActionPage.php(37): HTMLForm->show()
#14 /www/w/includes/SpecialPageFactory.php(459): ThreadActionPage->execute('Thread:User_tal...')
#15 /www/w/includes/Wiki.php(252): SpecialPageFactory::executePath(Object(Title), Object(RequestContext))
#16 /www/w/includes/Wiki.php(98): MediaWiki->handleSpecialCases()
#17 /www/w/index.php(145): MediaWiki->performRequestForTitle(NULL)
#18 {main}

1 files changed, 72 insertions, 6 deletions

diff --git a/includes/Action.php b/includes/Action.php
index 032d0949b586..5fbb5c701331 100644
--- a/includes/Action.php
+++ b/includes/Action.php
@@ -23,12 +23,16 @@
  *
  * @file
  */
-abstract class Action extends ContextSource {
+abstract class Action {
 
 	// Page on which we're performing the action
 	// @var Article
 	protected $page;
 
+	// RequestContext if specified; otherwise we'll use the Context from the Page
+	// @var RequestContext
+	protected $context;
+
 	// The fields used to create the HTMLForm
 	// @var Array
 	protected $fields;
@@ -87,13 +91,76 @@ abstract class Action extends ContextSource {
 	}
 
 	/**
+	 * Get the RequestContext in use here
+	 * @return RequestContext
+	 */
+	protected final function getContext() {
+		if ( $this->context instanceof RequestContext ) {
+			return $this->context;
+		}
+		return $this->page->getContext();
+	}
+
+	/**
+	 * Get the WebRequest being used for this instance
+	 *
+	 * @return WebRequest
+	 */
+	protected final function getRequest() {
+		return $this->getContext()->request;
+	}
+
+	/**
+	 * Get the OutputPage being used for this instance
+	 *
+	 * @return OutputPage
+	 */
+	protected final function getOutput() {
+		return $this->getContext()->output;
+	}
+
+	/**
+	 * Shortcut to get the User being used for this instance
+	 *
+	 * @return User
+	 */
+	protected final function getUser() {
+		return $this->getContext()->user;
+	}
+
+	/**
+	 * Shortcut to get the Skin being used for this instance
+	 *
+	 * @return Skin
+	 */
+	protected final function getSkin() {
+		return $this->getContext()->skin;
+	}
+
+	/**
+	 * Shortcut to get the user Language being used for this instance
+	 *
+	 * @return Skin
+	 */
+	protected final function getLang() {
+		return $this->getContext()->lang;
+	}
+
+	/**
+	 * Shortcut to get the Title object from the page
+	 * @return Title
+	 */
+	protected final function getTitle() {
+		return $this->page->getTitle();
+	}
+
+	/**
 	 * Protected constructor: use Action::factory( $action, $page ) to actually build
 	 * these things in the real world
 	 * @param Article $page
 	 */
 	protected function __construct( Article $page ) {
 		$this->page = $page;
-		$this->setContext( $page->getContext() );
 	}
 
 	/**
@@ -282,7 +349,7 @@ abstract class FormAction extends Action {
 	public function execute( array $data = null, $captureErrors = true ) {
 		try {
 			// Set a new context so output doesn't leak.
-			$this->setContext( clone $this->page->getContext() );
+			$this->context = clone $this->page->getContext();
 
 			// This will throw exceptions if there's a problem
 			$this->checkCanExecute( $this->getUser() );
@@ -364,11 +431,10 @@ abstract class FormlessAction extends Action {
 	public function execute( array $data = null, $captureErrors = true ) {
 		try {
 			// Set a new context so output doesn't leak.
-			$context = clone $this->page->getContext();
+			$this->context = clone $this->page->getContext();
 			if ( is_array( $data ) ) {
-				$context->setRequest( new FauxRequest( $data, false ) );
+				$this->context->setRequest( new FauxRequest( $data, false ) );
 			}
-			$this->setContext( $context );
 
 			// This will throw exceptions if there's a problem
 			$this->checkCanExecute( $this->getUser() );