From 20400cb21fd566c1cea4553cd040171096216654 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Wed, 24 Aug 2016 17:19:58 -0700
Subject: [PATCH] Move HTTP 304 check from performRequest to ViewAction

* Follow-up to 8b141886edebc
* The method is now called after the setCdnMaxage() call
  in performAction.
* Allow any CDN urls for the title now, check $wgDebugToolbar,
  and allows caching redirects. The multi-step redirect case does
  not cache however, for simplicity.
* Removed now-unused code in Article that calculated $timestamp.

Change-Id: Ic4f4e3a79d7d386c2f15ca5b11dddf5c57ff9e9f
---
 includes/MediaWiki.php          | 10 ----------
 includes/actions/ViewAction.php | 24 +++++++++++++++++++++++
 includes/page/Article.php       | 34 ++++++++++-----------------------
 3 files changed, 34 insertions(+), 34 deletions(-)

diff --git a/includes/MediaWiki.php b/includes/MediaWiki.php
index 2a00900b06..77ac76ae4c 100644
--- a/includes/MediaWiki.php
+++ b/includes/MediaWiki.php
@@ -286,16 +286,6 @@ class MediaWiki {
 				// may still be a wikipage redirect to another article or URL.
 				$article = $this->initializeArticle();
 				if ( is_object( $article ) ) {
-					$url = $request->getFullRequestURL(); // requested URL
-					if (
-						$request->getMethod() === 'GET' &&
-						$url === $article->getTitle()->getCanonicalURL() &&
-						$article->checkTouched() &&
-						$output->checkLastModified( $article->getTouched() )
-					) {
-						wfDebug( __METHOD__ . ": done 304\n" );
-						return;
-					}
 					$this->performAction( $article, $requestTitle );
 				} elseif ( is_string( $article ) ) {
 					$output->redirect( $article );
diff --git a/includes/actions/ViewAction.php b/includes/actions/ViewAction.php
index 3a24565c35..55507f5aa4 100644
--- a/includes/actions/ViewAction.php
+++ b/includes/actions/ViewAction.php
@@ -41,6 +41,30 @@ class ViewAction extends FormlessAction {
 	}
 
 	public function show() {
+		$config = $this->context->getConfig();
+
+		if (
+			$config->get( 'DebugToolbar' ) == false && // don't let this get stuck on pages
+			$this->page->checkTouched() // page exists and is not a redirect
+		) {
+			// Include any redirect in the last-modified calculation
+			$redirFromTitle = $this->page->getRedirectedFrom();
+			if ( !$redirFromTitle ) {
+				$touched = $this->page->getTouched();
+			} elseif ( $config->get( 'MaxRedirects' ) <= 1 ) {
+				$touched = max( $this->page->getTouched(), $redirFromTitle->getTouched() );
+			} else {
+				// Don't bother following the chain and getting the max mtime
+				$touched = null;
+			}
+
+			// Send HTTP 304 if the IMS matches or otherwise set expiry/last-modified headers
+			if ( $touched && $this->getOutput()->checkLastModified( $touched ) ) {
+				wfDebug( __METHOD__ . ": done 304\n" );
+				return;
+			}
+		}
+
 		$this->page->view();
 	}
 }
diff --git a/includes/page/Article.php b/includes/page/Article.php
index b3a97f7bf1..e299f7eece 100644
--- a/includes/page/Article.php
+++ b/includes/page/Article.php
@@ -149,6 +149,15 @@ class Article implements Page {
 		return $article;
 	}
 
+	/**
+	 * Get the page this view was redirected from
+	 * @return Title|null
+	 * @since 1.28
+	 */
+	public function getRedirectedFrom() {
+		return $this->mRedirectedFrom;
+	}
+
 	/**
 	 * Tell the page view functions that this view was redirected
 	 * from another page on the wiki.
@@ -467,7 +476,7 @@ class Article implements Page {
 	 * page of the given title.
 	 */
 	public function view() {
-		global $wgUseFileCache, $wgDebugToolbar, $wgMaxRedirects;
+		global $wgUseFileCache, $wgDebugToolbar;
 
 		# Get variables from query string
 		# As side effect this will load the revision and update the title
@@ -520,29 +529,6 @@ class Article implements Page {
 
 		# Try client and file cache
 		if ( !$wgDebugToolbar && $oldid === 0 && $this->mPage->checkTouched() ) {
-			# Use the greatest of the page's timestamp or the timestamp of any
-			# redirect in the chain (bug 67849)
-			$timestamp = $this->mPage->getTouched();
-			if ( isset( $this->mRedirectedFrom ) ) {
-				$timestamp = max( $timestamp, $this->mRedirectedFrom->getTouched() );
-
-				# If there can be more than one redirect in the chain, we have
-				# to go through the whole chain too in case an intermediate
-				# redirect was changed.
-				if ( $wgMaxRedirects > 1 ) {
-					$titles = Revision::newFromTitle( $this->mRedirectedFrom )
-						->getContent( Revision::FOR_THIS_USER, $user )
-						->getRedirectChain();
-					$thisTitle = $this->getTitle();
-					foreach ( $titles as $title ) {
-						if ( Title::compare( $title, $thisTitle ) === 0 ) {
-							break;
-						}
-						$timestamp = max( $timestamp, $title->getTouched() );
-					}
-				}
-			}
-
 			# Try to stream the output from file cache
 			if ( $wgUseFileCache && $this->tryFileCache() ) {
 				wfDebug( __METHOD__ . ": done file cache\n" );
-- 
2.20.1