From 56457b21bee95fce31b83b5436ca21a2e8c77627 Mon Sep 17 00:00:00 2001
From: Daniel Kinzler <daniel.kinzler@wikimedia.de>
Date: Tue, 20 Mar 2012 10:15:10 +0000
Subject: [PATCH] getUndoContent()

---
 includes/Content.php        | 11 +++++++++--
 includes/ContentHandler.php | 27 ++++++++++++++++++++++++++-
 includes/WikiPage.php       | 31 ++++++++++++++-----------------
 3 files changed, 49 insertions(+), 20 deletions(-)

diff --git a/includes/Content.php b/includes/Content.php
index fe2783a896..0fcb7179f3 100644
--- a/includes/Content.php
+++ b/includes/Content.php
@@ -40,6 +40,14 @@ abstract class Content {
         return $this->getSize() == 0;
     }
 
+    public function equals( Content $that ) {
+        if ( empty( $that ) ) return false;
+        if ( $that === $this ) return true;
+        if ( $that->getModelName() !== $this->getModelName() ) return false;
+
+        return $this->getNativeData() == $that->getNativeData();
+    }
+
     /**
      * Returns true if this content is countable as a "real" wiki page, provided
      * that it's also in a countable location (e.g. a current revision in the main namespace).
@@ -93,11 +101,10 @@ abstract class Content {
     # XXX: isCacheable( ) # can/should we do this here?
 
     # TODO: WikiPage::getUndoText( Revision $undo, Revision $undoafter = null )
-    # TODO: WikiPage::getAutosummary( $oldtext, $text, $flags )
 
     # TODO: EditPage::getPreloadedText( $preload ) // $wgParser->getPreloadText
     # TODO: tie into EditPage, make it use Content-objects throughout, make edit form aware of content model and format
-    # TODO: tie into WikiPage, make it use Content-objects throughout, especially in doEdit(), doDelete(), etc
+    # TODO: tie into WikiPage, make it use Content-objects throughout, especially in doEdit(), doDelete(), updateRevisionOn(), etc
     # TODO: make model-aware diff view!
     # TODO: handle ImagePage and CategoryPage
 
diff --git a/includes/ContentHandler.php b/includes/ContentHandler.php
index 39f9fcde36..96069adba4 100644
--- a/includes/ContentHandler.php
+++ b/includes/ContentHandler.php
@@ -380,8 +380,33 @@ abstract class ContentHandler {
         return $reason;
     }
 
+    /**
+     * Get the Content object that needs to be saved in order to undo all revisions
+     * between $undo and $undoafter. Revisions must belong to the same page,
+     * must exist and must not be deleted
+     * @param $undo Revision
+     * @param $undoafter Revision Must be an earlier revision than $undo
+     * @return mixed string on success, false on failure
+     */
+    public function getUndoContent( Revision $current, Revision $undo, Revision $undoafter ) {
+        $cur_content = $current->getContent();
+
+        if ( empty( $cur_content ) ) {
+            return false; // no page
+        }
+
+        $undo_content = $undo->getContent();
+        $undoafter_content = $undoafter->getContent();
 
-    #TODO: cover patch/undo just like merge3.
+        if ( $cur_content->equals( $undo_content ) ) {
+            # No use doing a merge if it's just a straight revert.
+            return $undoafter_content;
+        }
+
+        $undone_content = $this->merge3( $undo_content, $undoafter_content, $cur_content );
+
+        return $undone_content;
+    }
 
     #TODO: how to handle extra message for JS/CSS previews??
     #TODO: Article::showCssOrJsPage ---> specialized classes!
diff --git a/includes/WikiPage.php b/includes/WikiPage.php
index 4bf9ff9a78..42637e23f0 100644
--- a/includes/WikiPage.php
+++ b/includes/WikiPage.php
@@ -424,6 +424,11 @@ class WikiPage extends Page {
 		return $this->getText( Revision::RAW );
 	}
 
+    /**
+     * Get the content of the current revision. No side-effects...
+     *
+     * @return Contet|false The text of the current revision
+     */
     protected function getNativeData() {
         $content = $this->getContent( Revision::RAW );
         if ( !$content ) return null;
@@ -1097,27 +1102,19 @@ class WikiPage extends Page {
 	 * @param $undo Revision
 	 * @param $undoafter Revision Must be an earlier revision than $undo
 	 * @return mixed string on success, false on failure
+     * @deprecated since 1.20: use ContentHandler::getUndoContent() instead.
 	 */
-	public function getUndoText( Revision $undo, Revision $undoafter = null ) { #FIXME: move undo logic to ContentHandler
-		$cur_text = $this->getRawText();
-		if ( $cur_text === false ) {
-			return false; // no page
-		}
-		$undo_text = $undo->getText();
-		$undoafter_text = $undoafter->getText();
-
-		if ( $cur_text == $undo_text ) {
-			# No use doing a merge if it's just a straight revert.
-			return $undoafter_text;
-		}
+	public function getUndoText( Revision $undo, Revision $undoafter = null ) { #FIXME: replace usages.
+        $this->loadLastEdit();
 
-		$undone_text = '';
+        if ( $this->mLastRevision ) {
+            $handler = ContentHandler::getForTitle( $this->getTitle() );
+            $undone = $handler->getUndoContent( $this->mLastRevision, $undo, $undoafter );
 
-		if ( !wfMerge( $undo_text, $undoafter_text, $cur_text, $undone_text ) ) {
-			return false;
-		}
+            return ContentHandler::getContentText( $undone );
+        }
 
-		return $undone_text;
+        return false;
 	}
 
 	/**
-- 
2.20.1