From c8b3faddffdea876f9fda3b9dc4632a1b4e25591 Mon Sep 17 00:00:00 2001
From: Alexandre Emsenhuber <ialex@users.mediawiki.org>
Date: Sat, 30 Jul 2011 15:03:21 +0000
Subject: [PATCH] In Special:ComparePages: * Validate title and revision when
 passed * Don't display the diff if a field is not valid * Pass the context to
 the HTMLForm and removed the setTitle() call

---
 includes/specials/SpecialComparePages.php | 36 ++++++++++++++++++++---
 languages/messages/MessagesEn.php         | 17 ++++++-----
 maintenance/language/messages.inc         |  3 ++
 3 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/includes/specials/SpecialComparePages.php b/includes/specials/SpecialComparePages.php
index 6b9ef0a958..5531a6dde2 100644
--- a/includes/specials/SpecialComparePages.php
+++ b/includes/specials/SpecialComparePages.php
@@ -57,6 +57,7 @@ class SpecialComparePages extends SpecialPage {
 				'label-message' => 'compare-page1',
 				'size' => '40',
 				'section' => 'page1',
+				'validation-callback' => array( $this, 'checkExistingTitle' ),
 			),
 			'Revision1' => array(
 				'type' => 'int',
@@ -64,6 +65,7 @@ class SpecialComparePages extends SpecialPage {
 				'label-message' => 'compare-rev1',
 				'size' => '8',
 				'section' => 'page1',
+				'validation-callback' => array( $this, 'checkExistingRevision' ),
 			),
 			'Page2' => array(
 				'type' => 'text',
@@ -71,6 +73,7 @@ class SpecialComparePages extends SpecialPage {
 				'label-message' => 'compare-page2',
 				'size' => '40',
 				'section' => 'page2',
+				'validation-callback' => array( $this, 'checkExistingTitle' ),
 			),
 			'Revision2' => array(
 				'type' => 'int',
@@ -78,6 +81,7 @@ class SpecialComparePages extends SpecialPage {
 				'label-message' => 'compare-rev2',
 				'size' => '8',
 				'section' => 'page2',
+				'validation-callback' => array( $this, 'checkExistingRevision' ),
 			),
 			'Action' => array(
 				'type' => 'hidden',
@@ -87,16 +91,15 @@ class SpecialComparePages extends SpecialPage {
 				'type' => 'hidden',
 				'name' => 'diffonly',
 			),
-		), 'compare' );
+		), $this->getContext(), 'compare' );
 		$form->setSubmitText( wfMsg( 'compare-submit' ) );
 		$form->suppressReset();
 		$form->setMethod( 'get' );
-		$form->setTitle( $this->getTitle() );
+		$form->setSubmitCallback( array( __CLASS__, 'showDiff' ) );
 
 		$form->loadData();
 		$form->displayForm( '' );
-
-		self::showDiff( $form->mFieldData );
+		$form->trySubmit();
 	}
 
 	public static function showDiff( $data ){
@@ -125,4 +128,29 @@ class SpecialComparePages extends SpecialPage {
 		}
 		return null;
 	}
+
+	public function checkExistingTitle( $value, $alldata ) {
+		if ( $value === '' ) {
+			return true;
+		}
+		$title = Title::newFromText( $value );
+		if ( !$title instanceof Title ) {
+			return wfMsgExt( 'compare-invalid-title', 'parse' );
+		}
+		if ( !$title->exists() ) {
+			return wfMsgExt( 'compare-title-not-exists', 'parse' );
+		}
+		return true;
+	}
+
+	public function checkExistingRevision( $value, $alldata ) {
+		if ( $value === '' ) {
+			return true;
+		}
+		$revision = Revision::newFromId( $value );
+		if ( $revision === null ) {
+			return wfMsgExt( 'compare-revision-not-exists', 'parse' );
+		}
+		return true;
+	}
 }
diff --git a/languages/messages/MessagesEn.php b/languages/messages/MessagesEn.php
index 2903cdcfcf..ec19c9b1c1 100644
--- a/languages/messages/MessagesEn.php
+++ b/languages/messages/MessagesEn.php
@@ -4567,13 +4567,16 @@ Enter the file name without the "{{ns:file}}:" prefix.',
 'tags-hitcount'           => '$1 {{PLURAL:$1|change|changes}}',
 
 # Special:ComparePages
-'comparepages'     => 'Compare pages',
-'compare-selector' => 'Compare page revisions',
-'compare-page1'    => 'Page 1',
-'compare-page2'    => 'Page 2',
-'compare-rev1'     => 'Revision 1',
-'compare-rev2'     => 'Revision 2',
-'compare-submit'   => 'Compare',
+'comparepages'                => 'Compare pages',
+'compare-selector'            => 'Compare page revisions',
+'compare-page1'               => 'Page 1',
+'compare-page2'               => 'Page 2',
+'compare-rev1'                => 'Revision 1',
+'compare-rev2'                => 'Revision 2',
+'compare-submit'              => 'Compare',
+'compare-invalid-title'       => 'The title you specified is invalid.',
+'compare-title-not-exists'    => 'The title you specified does not exist.',
+'compare-revision-not-exists' => 'The revision you specified does not exist.',
 
 # Database error messages
 'dberr-header'      => 'This wiki has a problem',
diff --git a/maintenance/language/messages.inc b/maintenance/language/messages.inc
index 91c25fc019..82b168c208 100644
--- a/maintenance/language/messages.inc
+++ b/maintenance/language/messages.inc
@@ -3444,6 +3444,9 @@ $wgMessageStructure = array(
 		'compare-rev1',
 		'compare-rev2',
 		'compare-submit',
+		'compare-invalid-title',
+		'compare-title-not-exists',
+		'compare-revision-not-exists',
 	),
 	'db-error-messages' => array(
 		'dberr-header',
-- 
2.20.1