From 779f1024c102bc0833acc1d258693125e1673419 Mon Sep 17 00:00:00 2001
From: Jackmcbarn <jackmcbarn@gmail.com>
Date: Tue, 3 Jun 2014 16:10:02 -0400
Subject: [PATCH] Use preview content when it transcludes itself

When a page transcludes itself, such as <noinclude>foo
{{:{{FULLPAGENAME}}}}</noinclude><includeonly>bar</includeonly>, use the
preview content in its own transclusions. This code was basically ripped
straight from Extension:TemplateSandbox.

Bug: T85408
Bug: T7278
Change-Id: I1aa091a395a4f7b7b744e09e0bed59bc2e1176d0
---
 includes/EditPage.php             |  2 ++
 includes/parser/ParserOptions.php | 42 +++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/includes/EditPage.php b/includes/EditPage.php
index 2155c1b237..b65668e2a0 100644
--- a/includes/EditPage.php
+++ b/includes/EditPage.php
@@ -3561,6 +3561,8 @@ HTML
 			# But it's now deprecated, so never mind
 
 			$pstContent = $content->preSaveTransform( $this->mTitle, $wgUser, $parserOptions );
+			$scopedCallback = $parserOptions->setupFakeRevision(
+				$this->mTitle, $pstContent, $wgUser );
 			$parserOutput = $pstContent->getParserOutput( $this->mTitle, null, $parserOptions );
 
 			# Try to stash the edit for the final submission step
diff --git a/includes/parser/ParserOptions.php b/includes/parser/ParserOptions.php
index 7ad85a9371..ddeb90644e 100644
--- a/includes/parser/ParserOptions.php
+++ b/includes/parser/ParserOptions.php
@@ -818,4 +818,46 @@ class ParserOptions {
 
 		return $confstr;
 	}
+
+	/**
+	 * Sets a hook to force that a page exists, and sets a current revision callback to return a
+	 * revision with custom content when the current revision of the page is requested.
+	 *
+	 * @since 1.25
+	 * @param Title $title
+	 * @param Content $content
+	 * @param User $user The user that the fake revision is attributed to
+	 * @return ScopedCallback to unset the hook
+	 */
+	public function setupFakeRevision( $title, $content, $user ) {
+		$oldCallback = $this->setCurrentRevisionCallback( function ( $titleToCheck, $parser = false ) use ( $title, $content, $user, &$oldCallback ) {
+			if ( $titleToCheck->equals( $title ) ) {
+				return new Revision( array(
+					'page' => $title->getArticleID(),
+					'user_text' => $user->getName(),
+					'user' => $user->getId(),
+					'parent_id' => $title->getLatestRevId(),
+					'title' => $title,
+					'content' => $content
+				) );
+			} else {
+				return call_user_func( $oldCallback, $titleToCheck, $parser );
+			}
+		} );
+		global $wgHooks;
+		$wgHooks['TitleExists'][] =
+			function ( $titleToCheck, &$exists ) use ( $title ) {
+				if ( $titleToCheck->equals( $title ) ) {
+					$exists = true;
+				}
+			};
+		end( $wgHooks['TitleExists'] );
+		$key = key( $wgHooks['TitleExists'] );
+		LinkCache::singleton()->clearBadLink( $title->getPrefixedDBkey() );
+		return new ScopedCallback( function () use ( $title, $key ) {
+			global $wgHooks;
+			unset( $wgHooks['TitleExists'][$key] );
+			LinkCache::singleton()->clearLink( $title );
+		} );
+	}
 }
-- 
2.20.1