From 222b01f5169f1c7e69762e0e8904c24f78f71882 Mon Sep 17 00:00:00 2001
From: Pierre Schmitz <pierre@archlinux.de>
Date: Wed, 28 Jul 2010 11:52:48 +0200
Subject: update to MediaWiki 1.16.0

---
 includes/diff/DifferenceInterface.php | 1021 +++++++++++++++++++++++++++++++++
 1 file changed, 1021 insertions(+)
 create mode 100644 includes/diff/DifferenceInterface.php

(limited to 'includes/diff/DifferenceInterface.php')

diff --git a/includes/diff/DifferenceInterface.php b/includes/diff/DifferenceInterface.php
new file mode 100644
index 00000000..d7d36799
--- /dev/null
+++ b/includes/diff/DifferenceInterface.php
@@ -0,0 +1,1021 @@
+<?php
+/**
+ * @defgroup DifferenceEngine DifferenceEngine
+ */
+ 
+/**
+ * Constant to indicate diff cache compatibility.
+ * Bump this when changing the diff formatting in a way that
+ * fixes important bugs or such to force cached diff views to
+ * clear.
+ */
+define( 'MW_DIFF_VERSION', '1.11a' );
+
+/**
+ * @todo document
+ * @ingroup DifferenceEngine
+ */
+class DifferenceEngine {
+	/**#@+
+	 * @private
+	 */
+	var $mOldid, $mNewid, $mTitle;
+	var $mOldtitle, $mNewtitle, $mPagetitle;
+	var $mOldtext, $mNewtext;
+	var $mOldPage, $mNewPage;
+	var $mRcidMarkPatrolled;
+	var $mOldRev, $mNewRev;
+	var $mRevisionsLoaded = false; // Have the revisions been loaded
+	var $mTextLoaded = 0; // How many text blobs have been loaded, 0, 1 or 2?
+	var $mCacheHit = false; // Was the diff fetched from cache?
+
+	/**
+	 * Set this to true to add debug info to the HTML output.
+	 * Warning: this may cause RSS readers to spuriously mark articles as "new"
+	 * (bug 20601)
+	 */
+	var $enableDebugComment = false;
+
+	// If true, line X is not displayed when X is 1, for example to increase
+	// readability and conserve space with many small diffs.
+	protected $mReducedLineNumbers = false;
+
+	protected $unhide = false;
+	/**#@-*/
+
+	/**
+	 * Constructor
+	 * @param $titleObj Title object that the diff is associated with
+	 * @param $old Integer: old ID we want to show and diff with.
+	 * @param $new String: either 'prev' or 'next'.
+	 * @param $rcid Integer: ??? FIXME (default 0)
+	 * @param $refreshCache boolean If set, refreshes the diff cache
+	 * @param $unhide boolean If set, allow viewing deleted revs
+	 */
+	function __construct( $titleObj = null, $old = 0, $new = 0, $rcid = 0,
+		$refreshCache = false, $unhide = false )
+	{
+		if ( $titleObj ) {
+			$this->mTitle = $titleObj;
+		} else {
+			global $wgTitle;
+			$this->mTitle = $wgTitle;
+		}
+		wfDebug("DifferenceEngine old '$old' new '$new' rcid '$rcid'\n");
+
+		if ( 'prev' === $new ) {
+			# Show diff between revision $old and the previous one.
+			# Get previous one from DB.
+			$this->mNewid = intval($old);
+			$this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid );
+		} elseif ( 'next' === $new ) {
+			# Show diff between revision $old and the next one.
+			# Get next one from DB.
+			$this->mOldid = intval($old);
+			$this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid );
+			if ( false === $this->mNewid ) {
+				# if no result, NewId points to the newest old revision. The only newer
+				# revision is cur, which is "0".
+				$this->mNewid = 0;
+			}
+		} else {
+			$this->mOldid = intval($old);
+			$this->mNewid = intval($new);
+			wfRunHooks( 'NewDifferenceEngine', array(&$titleObj, &$this->mOldid, &$this->mNewid, $old, $new) ); 
+		}
+		$this->mRcidMarkPatrolled = intval($rcid);  # force it to be an integer
+		$this->mRefreshCache = $refreshCache;
+		$this->unhide = $unhide;
+	}
+
+	function setReducedLineNumbers( $value = true ) {
+		$this->mReducedLineNumbers = $value;
+	}
+
+	function getTitle() {
+		return $this->mTitle;
+	}
+	
+	function wasCacheHit() {
+		return $this->mCacheHit;
+	}
+	
+	function getOldid() {
+		return $this->mOldid;
+	}
+	
+	function getNewid() {
+		return $this->mNewid;
+	}
+
+	function showDiffPage( $diffOnly = false ) {
+		global $wgUser, $wgOut, $wgUseExternalEditor, $wgUseRCPatrol;
+		wfProfileIn( __METHOD__ );
+
+
+		# If external diffs are enabled both globally and for the user,
+		# we'll use the application/x-external-editor interface to call
+		# an external diff tool like kompare, kdiff3, etc.
+		if($wgUseExternalEditor && $wgUser->getOption('externaldiff')) {
+			global $wgInputEncoding,$wgServer,$wgScript,$wgLang;
+			$wgOut->disable();
+			header ( "Content-type: application/x-external-editor; charset=".$wgInputEncoding );
+			$url1=$this->mTitle->getFullURL( array(
+				'action' => 'raw',
+				'oldid' => $this->mOldid
+			) );
+			$url2=$this->mTitle->getFullURL( array(
+				'action' => 'raw',
+				'oldid' => $this->mNewid
+			) );
+			$special=$wgLang->getNsText(NS_SPECIAL);
+			$control=<<<CONTROL
+			[Process]
+			Type=Diff text
+			Engine=MediaWiki
+			Script={$wgServer}{$wgScript}
+			Special namespace={$special}
+
+			[File]
+			Extension=wiki
+			URL=$url1
+
+			[File 2]
+			Extension=wiki
+			URL=$url2
+CONTROL;
+			echo($control);
+			return;
+		}
+
+		$wgOut->setArticleFlag( false );
+		if ( !$this->loadRevisionData() ) {
+			$t = $this->mTitle->getPrefixedText();
+			$d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
+			$wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
+			$wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", $d );
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+
+		wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
+
+		if ( $this->mNewRev->isCurrent() ) {
+			$wgOut->setArticleFlag( true );
+		}
+
+		# mOldid is false if the difference engine is called with a "vague" query for
+		# a diff between a version V and its previous version V' AND the version V
+		# is the first version of that article. In that case, V' does not exist.
+		if ( $this->mOldid === false ) {
+			$this->showFirstRevision();
+			$this->renderNewRevision();  // should we respect $diffOnly here or not?
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+
+		$wgOut->suppressQuickbar();
+
+		$oldTitle = $this->mOldPage->getPrefixedText();
+		$newTitle = $this->mNewPage->getPrefixedText();
+		if( $oldTitle == $newTitle ) {
+			$wgOut->setPageTitle( $newTitle );
+		} else {
+			$wgOut->setPageTitle( $oldTitle . ', ' . $newTitle );
+		}
+		$wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
+		$wgOut->setRobotPolicy( 'noindex,nofollow' );
+
+		if ( !$this->mOldPage->userCanRead() || !$this->mNewPage->userCanRead() ) {
+			$wgOut->loginToUse();
+			$wgOut->output();
+			$wgOut->disable();
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+
+		$sk = $wgUser->getSkin();
+
+		// Check if page is editable
+		$editable = $this->mNewRev->getTitle()->userCan( 'edit' );
+		if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) {
+			$rollback = '&nbsp;&nbsp;&nbsp;' . $sk->generateRollback( $this->mNewRev );
+		} else {
+			$rollback = '';
+		}
+
+		// Prepare a change patrol link, if applicable
+		if( $wgUseRCPatrol && $this->mTitle->userCan('patrol') ) {
+			// If we've been given an explicit change identifier, use it; saves time
+			if( $this->mRcidMarkPatrolled ) {
+				$rcid = $this->mRcidMarkPatrolled;
+				$rc = RecentChange::newFromId( $rcid );
+				// Already patrolled?
+				$rcid = is_object($rc) && !$rc->getAttribute('rc_patrolled') ? $rcid : 0;
+			} else {
+				// Look for an unpatrolled change corresponding to this diff
+				$db = wfGetDB( DB_SLAVE );
+				$change = RecentChange::newFromConds(
+					array(
+					// Redundant user,timestamp condition so we can use the existing index
+						'rc_user_text'  => $this->mNewRev->getRawUserText(),
+						'rc_timestamp'  => $db->timestamp( $this->mNewRev->getTimestamp() ),
+						'rc_this_oldid' => $this->mNewid,
+						'rc_last_oldid' => $this->mOldid,
+						'rc_patrolled'  => 0
+					),
+					__METHOD__
+				);
+				if( $change instanceof RecentChange ) {
+					$rcid = $change->mAttribs['rc_id'];
+					$this->mRcidMarkPatrolled = $rcid;
+				} else {
+					// None found
+					$rcid = 0;
+				}
+			}
+			// Build the link
+			if( $rcid ) {
+				$patrol = ' <span class="patrollink">[' . $sk->link(
+					$this->mTitle, 
+					wfMsgHtml( 'markaspatrolleddiff' ),
+					array(),
+					array(
+						'action' => 'markpatrolled',
+						'rcid' => $rcid
+					),
+					array(
+						'known',
+						'noclasses'
+					)
+				) . ']</span>';
+			} else {
+				$patrol = '';
+			}
+		} else {
+			$patrol = '';
+		}
+
+		# Carry over 'diffonly' param via navigation links
+		if( $diffOnly != $wgUser->getBoolOption('diffonly') ) {
+			$query['diffonly'] = $diffOnly;
+		}
+
+		# Make "previous revision link"
+		$query['diff'] = 'prev';
+		$query['oldid'] = $this->mOldid;
+		# Cascade unhide param in links for easy deletion browsing
+		if( $this->unhide ) {
+			$query['unhide'] = 1;
+		}
+		$prevlink = $sk->link(
+			$this->mTitle,
+			wfMsgHtml( 'previousdiff' ),
+			array(
+				'id' => 'differences-prevlink'
+			),
+			$query,
+			array(
+				'known',
+				'noclasses'
+			)
+		);
+
+		# Make "next revision link"
+		$query['diff'] = 'next';
+		$query['oldid'] = $this->mNewid;
+		# Skip next link on the top revision
+		if( $this->mNewRev->isCurrent() ) {
+			$nextlink = '&nbsp;';
+		} else {
+			$nextlink = $sk->link(
+				$this->mTitle,
+				wfMsgHtml( 'nextdiff' ),
+				array(
+					'id' => 'differences-nextlink'
+				),
+				$query,
+				array(
+					'known',
+					'noclasses'
+				)
+			);
+		}
+
+		$oldminor = '';
+		$newminor = '';
+
+		if( $this->mOldRev->isMinor() ) {
+			$oldminor = ChangesList::flag( 'minor' );
+		}
+		if( $this->mNewRev->isMinor() ) {
+			$newminor = ChangesList::flag( 'minor' );
+		}
+
+		# Handle RevisionDelete links...
+		$ldel = $this->revisionDeleteLink( $this->mOldRev );
+		$rdel = $this->revisionDeleteLink( $this->mNewRev );
+
+		$oldHeader = '<div id="mw-diff-otitle1"><strong>'.$this->mOldtitle.'</strong></div>' .
+			'<div id="mw-diff-otitle2">' .
+				$sk->revUserTools( $this->mOldRev, !$this->unhide ).'</div>' .
+			'<div id="mw-diff-otitle3">' . $oldminor .
+				$sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ).$ldel.'</div>' .
+			'<div id="mw-diff-otitle4">' . $prevlink .'</div>';
+		$newHeader = '<div id="mw-diff-ntitle1"><strong>'.$this->mNewtitle.'</strong></div>' .
+			'<div id="mw-diff-ntitle2">' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) .
+				" $rollback</div>" .
+			'<div id="mw-diff-ntitle3">' . $newminor .
+				$sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ).$rdel.'</div>' .
+			'<div id="mw-diff-ntitle4">' . $nextlink . $patrol . '</div>';
+
+		# Check if this user can see the revisions
+		$allowed = $this->mOldRev->userCan(Revision::DELETED_TEXT)
+			&& $this->mNewRev->userCan(Revision::DELETED_TEXT);
+		# Check if one of the revisions is deleted/suppressed
+		$deleted = $suppressed = false;
+		if( $this->mOldRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$deleted = true; // old revisions text is hidden
+			if( $this->mOldRev->isDeleted(Revision::DELETED_RESTRICTED) )
+				$suppressed = true; // also suppressed
+		}
+		if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$deleted = true; // new revisions text is hidden
+			if( $this->mNewRev->isDeleted(Revision::DELETED_RESTRICTED) )
+				$suppressed = true; // also suppressed
+		}
+		# If the diff cannot be shown due to a deleted revision, then output
+		# the diff header and links to unhide (if available)...
+		if( $deleted && (!$this->unhide || !$allowed) ) {
+			$this->showDiffStyle();
+			$multi = $this->getMultiNotice();
+			$wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
+			if( !$allowed ) {
+				$msg = $suppressed ? 'rev-suppressed-no-diff' : 'rev-deleted-no-diff';
+				# Give explanation for why revision is not visible
+				$wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n",
+					array( $msg ) );
+			} else {
+				# Give explanation and add a link to view the diff...
+				$link = $this->mTitle->getFullUrl( array(
+					'diff' => $this->mNewid,
+					'oldid' => $this->mOldid,
+					'unhide' => 1
+				) );
+				$msg = $suppressed ? 'rev-suppressed-unhide-diff' : 'rev-deleted-unhide-diff';
+				$wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n", array( $msg, $link ) );
+			}
+		# Otherwise, output a regular diff...
+		} else {
+			# Add deletion notice if the user is viewing deleted content
+			$notice = '';
+			if( $deleted ) {
+				$msg = $suppressed ? 'rev-suppressed-diff-view' : 'rev-deleted-diff-view';
+				$notice = "<div class='mw-warning plainlinks'>\n".wfMsgExt($msg,'parseinline')."</div>\n";
+			}
+			$this->showDiff( $oldHeader, $newHeader, $notice );
+			if( !$diffOnly ) {
+				$this->renderNewRevision();
+			}
+		}
+		wfProfileOut( __METHOD__ );
+	}
+	
+	protected function revisionDeleteLink( $rev ) {
+		global $wgUser;
+		$link = '';
+		$canHide = $wgUser->isAllowed( 'deleterevision' );
+		// Show del/undel link if:
+		// (a) the user can delete revisions, or
+		// (b) the user can view deleted revision *and* this one is deleted
+		if( $canHide || ($rev->getVisibility() && $wgUser->isAllowed( 'deletedhistory' )) ) {
+			$sk = $wgUser->getSkin();
+			if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
+				$link = $sk->revDeleteLinkDisabled( $canHide ); // revision was hidden from sysops
+			} else {
+				$query = array(
+					'type' 	 => 'revision',
+					'target' => $rev->mTitle->getPrefixedDbkey(),
+					'ids' 	 => $rev->getId()
+				);
+				$link = $sk->revDeleteLink( $query,
+					$rev->isDeleted( Revision::DELETED_RESTRICTED ), $canHide );
+			}
+			$link = '&nbsp;&nbsp;&nbsp;' . $link . ' ';
+		}
+		return $link;
+	}
+
+	/**
+	 * Show the new revision of the page.
+	 */
+	function renderNewRevision() {
+		global $wgOut, $wgUser;
+		wfProfileIn( __METHOD__ );
+
+		$wgOut->addHTML( "<hr /><h2>{$this->mPagetitle}</h2>\n" );
+		# Add deleted rev tag if needed
+		if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
+			$wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n", 'rev-deleted-text-permission' );
+		} else if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n", 'rev-deleted-text-view' );
+		}
+
+		if( !$this->mNewRev->isCurrent() ) {
+			$oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
+		}
+
+		$this->loadNewText();
+		if( is_object( $this->mNewRev ) ) {
+			$wgOut->setRevisionId( $this->mNewRev->getId() );
+		}
+
+		if( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
+			// Stolen from Article::view --AG 2007-10-11
+			// Give hooks a chance to customise the output
+			if( wfRunHooks( 'ShowRawCssJs', array( $this->mNewtext, $this->mTitle, $wgOut ) ) ) {
+				// Wrap the whole lot in a <pre> and don't parse
+				$m = array();
+				preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
+				$wgOut->addHTML( "<pre class=\"mw-code mw-{$m[1]}\" dir=\"ltr\">\n" );
+				$wgOut->addHTML( htmlspecialchars( $this->mNewtext ) );
+				$wgOut->addHTML( "\n</pre>\n" );
+			}
+		} else {
+			$wgOut->addWikiTextTidy( $this->mNewtext );
+		}
+
+		if( is_object( $this->mNewRev ) && !$this->mNewRev->isCurrent() ) {
+			$wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
+		}
+		# Add redundant patrol link on bottom...
+		if( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan('patrol') ) {
+			$sk = $wgUser->getSkin();
+			$wgOut->addHTML(
+				"<div class='patrollink'>[" . $sk->link(
+					$this->mTitle,
+					wfMsgHtml( 'markaspatrolleddiff' ),
+					array(),
+					array(
+						'action' => 'markpatrolled',
+						'rcid' => $this->mRcidMarkPatrolled
+					)
+				) . ']</div>'
+			 );
+		}
+
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Show the first revision of an article. Uses normal diff headers in
+	 * contrast to normal "old revision" display style.
+	 */
+	function showFirstRevision() {
+		global $wgOut, $wgUser;
+		wfProfileIn( __METHOD__ );
+
+		# Get article text from the DB
+		#
+		if ( ! $this->loadNewText() ) {
+			$t = $this->mTitle->getPrefixedText();
+			$d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
+			$wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
+			$wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", $d );
+			wfProfileOut( __METHOD__ );
+			return;
+		}
+		if ( $this->mNewRev->isCurrent() ) {
+			$wgOut->setArticleFlag( true );
+		}
+
+		# Check if user is allowed to look at this page. If not, bail out.
+		#
+		if ( !$this->mTitle->userCanRead() ) {
+			$wgOut->loginToUse();
+			$wgOut->output();
+			wfProfileOut( __METHOD__ );
+			throw new MWException("Permission Error: you do not have access to view this page");
+		}
+
+		# Prepare the header box
+		#
+		$sk = $wgUser->getSkin();
+
+		$next = $this->mTitle->getNextRevisionID( $this->mNewid );
+		if( !$next ) {
+			$nextlink = '';
+		} else {
+			$nextlink = '<br />' . $sk->link(
+				$this->mTitle,
+				wfMsgHtml( 'nextdiff' ),
+				array(
+					'id' => 'differences-nextlink'
+				),
+				array(
+					'diff' => 'next',
+					'oldid' => $this->mNewid,
+				),
+				array(
+					'known',
+					'noclasses'
+				)
+			);
+		}
+		$header = "<div class=\"firstrevisionheader\" style=\"text-align: center\">" .
+			$sk->revUserTools( $this->mNewRev ) . "<br />" . $sk->revComment( $this->mNewRev ) . $nextlink . "</div>\n";
+
+		$wgOut->addHTML( $header );
+
+		$wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
+		$wgOut->setRobotPolicy( 'noindex,nofollow' );
+
+		wfProfileOut( __METHOD__ );
+	}
+
+	/**
+	 * Get the diff text, send it to $wgOut
+	 * Returns false if the diff could not be generated, otherwise returns true
+	 */
+	function showDiff( $otitle, $ntitle, $notice = '' ) {
+		global $wgOut;
+		$diff = $this->getDiff( $otitle, $ntitle, $notice );
+		if ( $diff === false ) {
+			$wgOut->addWikiMsg( 'missing-article', "<nowiki>(fixme, bug)</nowiki>", '' );
+			return false;
+		} else {
+			$this->showDiffStyle();
+			$wgOut->addHTML( $diff );
+			return true;
+		}
+	}
+
+	/**
+	 * Add style sheets and supporting JS for diff display.
+	 */
+	function showDiffStyle() {
+		global $wgStylePath, $wgStyleVersion, $wgOut;
+		$wgOut->addStyle( 'common/diff.css' );
+
+		// JS is needed to detect old versions of Mozilla to work around an annoyance bug.
+		$wgOut->addScript( "<script type=\"text/javascript\" src=\"$wgStylePath/common/diff.js?$wgStyleVersion\"></script>" );
+	}
+
+	/**
+	 * Get complete diff table, including header
+	 *
+	 * @param Title $otitle Old title
+	 * @param Title $ntitle New title
+	 * @param string $notice HTML between diff header and body
+	 * @return mixed
+	 */
+	function getDiff( $otitle, $ntitle, $notice = '' ) {
+		$body = $this->getDiffBody();
+		if ( $body === false ) {
+			return false;
+		} else {
+			$multi = $this->getMultiNotice();
+			return $this->addHeader( $body, $otitle, $ntitle, $multi, $notice );
+		}
+	}
+
+	/**
+	 * Get the diff table body, without header
+	 *
+	 * @return mixed
+	 */
+	function getDiffBody() {
+		global $wgMemc;
+		wfProfileIn( __METHOD__ );
+		$this->mCacheHit = true;
+		// Check if the diff should be hidden from this user
+		if ( !$this->loadRevisionData() )
+			return '';
+		if ( $this->mOldRev && !$this->mOldRev->userCan(Revision::DELETED_TEXT) ) {
+			return '';
+		} else if ( $this->mNewRev && !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
+			return '';
+		} else if ( $this->mOldRev && $this->mNewRev && $this->mOldRev->getID() == $this->mNewRev->getID() ) {
+			return '';
+		}
+		// Cacheable?
+		$key = false;
+		if ( $this->mOldid && $this->mNewid ) {
+			$key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION, 'oldid', $this->mOldid, 'newid', $this->mNewid );
+			// Try cache
+			if ( !$this->mRefreshCache ) {
+				$difftext = $wgMemc->get( $key );
+				if ( $difftext ) {
+					wfIncrStats( 'diff_cache_hit' );
+					$difftext = $this->localiseLineNumbers( $difftext );
+					$difftext .= "\n<!-- diff cache key $key -->\n";
+					wfProfileOut( __METHOD__ );
+					return $difftext;
+				}
+			} // don't try to load but save the result
+		}
+		$this->mCacheHit = false;
+
+		// Loadtext is permission safe, this just clears out the diff
+		if ( !$this->loadText() ) {
+			wfProfileOut( __METHOD__ );
+			return false;
+		}
+
+		$difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
+
+		// Save to cache for 7 days
+		if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
+			wfIncrStats( 'diff_uncacheable' );
+		} else if ( $key !== false && $difftext !== false ) {
+			wfIncrStats( 'diff_cache_miss' );
+			$wgMemc->set( $key, $difftext, 7*86400 );
+		} else {
+			wfIncrStats( 'diff_uncacheable' );
+		}
+		// Replace line numbers with the text in the user's language
+		if ( $difftext !== false ) {
+			$difftext = $this->localiseLineNumbers( $difftext );
+		}
+		wfProfileOut( __METHOD__ );
+		return $difftext;
+	}
+
+	/**
+	 * Make sure the proper modules are loaded before we try to
+	 * make the diff
+	 */
+	private function initDiffEngines() {
+		global $wgExternalDiffEngine;
+		if ( $wgExternalDiffEngine == 'wikidiff' && !function_exists( 'wikidiff_do_diff' ) ) {
+			wfProfileIn( __METHOD__ . '-php_wikidiff.so' );
+			wfSuppressWarnings();
+			dl( 'php_wikidiff.so' );
+			wfRestoreWarnings();
+			wfProfileOut( __METHOD__ . '-php_wikidiff.so' );
+		}
+		else if ( $wgExternalDiffEngine == 'wikidiff2' && !function_exists( 'wikidiff2_do_diff' ) ) {
+			wfProfileIn( __METHOD__ . '-php_wikidiff2.so' );
+			wfSuppressWarnings();
+			dl( 'php_wikidiff2.so' );
+			wfRestoreWarnings();
+			wfProfileOut( __METHOD__ . '-php_wikidiff2.so' );
+		}
+	}
+
+	/**
+	 * Generate a diff, no caching
+	 * $otext and $ntext must be already segmented
+	 */
+	function generateDiffBody( $otext, $ntext ) {
+		global $wgExternalDiffEngine, $wgContLang;
+
+		$otext = str_replace( "\r\n", "\n", $otext );
+		$ntext = str_replace( "\r\n", "\n", $ntext );
+
+		$this->initDiffEngines();
+
+		if ( $wgExternalDiffEngine == 'wikidiff' && function_exists( 'wikidiff_do_diff' ) ) {
+			# For historical reasons, external diff engine expects
+			# input text to be HTML-escaped already
+			$otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
+			$ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
+			return $wgContLang->unsegementForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
+			$this->debug( 'wikidiff1' );
+		}
+
+		if ( $wgExternalDiffEngine == 'wikidiff2' && function_exists( 'wikidiff2_do_diff' ) ) {
+			# Better external diff engine, the 2 may some day be dropped
+			# This one does the escaping and segmenting itself
+			wfProfileIn( 'wikidiff2_do_diff' );
+			$text = wikidiff2_do_diff( $otext, $ntext, 2 );
+			$text .= $this->debug( 'wikidiff2' );
+			wfProfileOut( 'wikidiff2_do_diff' );
+			return $text;
+		}
+		if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
+			# Diff via the shell
+			global $wgTmpDirectory;
+			$tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
+			$tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
+
+			$tempFile1 = fopen( $tempName1, "w" );
+			if ( !$tempFile1 ) {
+				wfProfileOut( __METHOD__ );
+				return false;
+			}
+			$tempFile2 = fopen( $tempName2, "w" );
+			if ( !$tempFile2 ) {
+				wfProfileOut( __METHOD__ );
+				return false;
+			}
+			fwrite( $tempFile1, $otext );
+			fwrite( $tempFile2, $ntext );
+			fclose( $tempFile1 );
+			fclose( $tempFile2 );
+			$cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
+			wfProfileIn( __METHOD__ . "-shellexec" );
+			$difftext = wfShellExec( $cmd );
+			$difftext .= $this->debug( "external $wgExternalDiffEngine" );
+			wfProfileOut( __METHOD__ . "-shellexec" );
+			unlink( $tempName1 );
+			unlink( $tempName2 );
+			return $difftext;
+		}
+
+		# Native PHP diff
+		$ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
+		$nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
+		$diffs = new Diff( $ota, $nta );
+		$formatter = new TableDiffFormatter();
+		return $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
+		$this->debug();
+	}
+
+	/**
+	 * Generate a debug comment indicating diff generating time,
+	 * server node, and generator backend.
+	 */
+	protected function debug( $generator="internal" ) {
+		global $wgShowHostnames;
+		if ( !$this->enableDebugComment ) {
+			return '';
+		}
+		$data = array( $generator );
+		if( $wgShowHostnames ) {
+			$data[] = wfHostname();
+		}
+		$data[] = wfTimestamp( TS_DB );
+		return "<!-- diff generator: " .
+		implode( " ",
+		array_map(
+					"htmlspecialchars",
+		$data ) ) .
+			" -->\n";
+	}
+
+	/**
+	 * Replace line numbers with the text in the user's language
+	 */
+	function localiseLineNumbers( $text ) {
+		return preg_replace_callback( '/<!--LINE (\d+)-->/',
+		array( &$this, 'localiseLineNumbersCb' ), $text );
+	}
+
+	function localiseLineNumbersCb( $matches ) {
+		global $wgLang;
+		if ( $matches[1] === '1' && $this->mReducedLineNumbers ) return '';
+		return wfMsgExt( 'lineno', 'escape', $wgLang->formatNum( $matches[1] ) );
+	}
+
+
+	/**
+	 * If there are revisions between the ones being compared, return a note saying so.
+	 */
+	function getMultiNotice() {
+		if ( !is_object($this->mOldRev) || !is_object($this->mNewRev) )
+		return '';
+
+		if( !$this->mOldPage->equals( $this->mNewPage ) ) {
+			// Comparing two different pages? Count would be meaningless.
+			return '';
+		}
+
+		$oldid = $this->mOldRev->getId();
+		$newid = $this->mNewRev->getId();
+		if ( $oldid > $newid ) {
+			$tmp = $oldid; $oldid = $newid; $newid = $tmp;
+		}
+
+		$n = $this->mTitle->countRevisionsBetween( $oldid, $newid );
+		if ( !$n )
+		return '';
+
+		return wfMsgExt( 'diff-multi', array( 'parseinline' ), $n );
+	}
+
+
+	/**
+	 * Add the header to a diff body
+	 */
+	static function addHeader( $diff, $otitle, $ntitle, $multi = '', $notice = '' ) {
+		$header = "<table class='diff'>";
+		if( $diff ) { // Safari/Chrome show broken output if cols not used
+			$header .= "
+			<col class='diff-marker' />
+			<col class='diff-content' />
+			<col class='diff-marker' />
+			<col class='diff-content' />";
+			$colspan = 2;
+			$multiColspan = 4;
+		} else {
+			$colspan = 1;
+			$multiColspan = 2;
+		}
+		$header .= "
+		<tr valign='top'>
+		<td colspan='$colspan' class='diff-otitle'>{$otitle}</td>
+		<td colspan='$colspan' class='diff-ntitle'>{$ntitle}</td>
+		</tr>";
+
+		if ( $multi != '' ) {
+			$header .= "<tr><td colspan='{$multiColspan}' align='center' class='diff-multi'>{$multi}</td></tr>";
+		}
+		if ( $notice != '' ) {
+			$header .= "<tr><td colspan='{$multiColspan}' align='center'>{$notice}</td></tr>";
+		}
+
+		return $header . $diff . "</table>";
+	}
+
+	/**
+	 * Use specified text instead of loading from the database
+	 */
+	function setText( $oldText, $newText ) {
+		$this->mOldtext = $oldText;
+		$this->mNewtext = $newText;
+		$this->mTextLoaded = 2;
+		$this->mRevisionsLoaded = true;
+	}
+
+	/**
+	 * Load revision metadata for the specified articles. If newid is 0, then compare
+	 * the old article in oldid to the current article; if oldid is 0, then
+	 * compare the current article to the immediately previous one (ignoring the
+	 * value of newid).
+	 *
+	 * If oldid is false, leave the corresponding revision object set
+	 * to false. This is impossible via ordinary user input, and is provided for
+	 * API convenience.
+	 */
+	function loadRevisionData() {
+		global $wgLang, $wgUser;
+		if ( $this->mRevisionsLoaded ) {
+			return true;
+		} else {
+			// Whether it succeeds or fails, we don't want to try again
+			$this->mRevisionsLoaded = true;
+		}
+
+		// Load the new revision object
+		$this->mNewRev = $this->mNewid
+			? Revision::newFromId( $this->mNewid )
+			: Revision::newFromTitle( $this->mTitle );
+		if( !$this->mNewRev instanceof Revision )
+			return false;
+
+		// Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
+		$this->mNewid = $this->mNewRev->getId();
+
+		// Check if page is editable
+		$editable = $this->mNewRev->getTitle()->userCan( 'edit' );
+
+		// Set assorted variables
+		$timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
+		$dateofrev = $wgLang->date( $this->mNewRev->getTimestamp(), true );
+		$timeofrev = $wgLang->time( $this->mNewRev->getTimestamp(), true );
+		$this->mNewPage = $this->mNewRev->getTitle();
+		if( $this->mNewRev->isCurrent() ) {
+			$newLink = $this->mNewPage->escapeLocalUrl( array(
+				'oldid' => $this->mNewid
+			) );
+			$this->mPagetitle = htmlspecialchars( wfMsg(
+				'currentrev-asof',
+				$timestamp,
+				$dateofrev,
+				$timeofrev
+			) );
+			$newEdit = $this->mNewPage->escapeLocalUrl( array(
+				'action' => 'edit'
+			) );
+
+			$this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
+			$this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
+		} else {
+			$newLink = $this->mNewPage->escapeLocalUrl( array(
+				'oldid' => $this->mNewid
+			) );
+			$newEdit = $this->mNewPage->escapeLocalUrl( array(
+				'action' => 'edit',
+				'oldid' => $this->mNewid
+			) );
+			$this->mPagetitle = htmlspecialchars( wfMsg(
+				'revisionasof',
+				$timestamp,
+				$dateofrev,
+				$timeofrev
+			) );
+
+			$this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
+			$this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
+		}
+		if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
+			$this->mNewtitle = "<span class='history-deleted'>{$this->mPagetitle}</span>";
+		} else if ( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
+			$this->mNewtitle = "<span class='history-deleted'>{$this->mNewtitle}</span>";
+		}
+
+		// Load the old revision object
+		$this->mOldRev = false;
+		if( $this->mOldid ) {
+			$this->mOldRev = Revision::newFromId( $this->mOldid );
+		} elseif ( $this->mOldid === 0 ) {
+			$rev = $this->mNewRev->getPrevious();
+			if( $rev ) {
+				$this->mOldid = $rev->getId();
+				$this->mOldRev = $rev;
+			} else {
+				// No previous revision; mark to show as first-version only.
+				$this->mOldid = false;
+				$this->mOldRev = false;
+			}
+		}/* elseif ( $this->mOldid === false ) leave mOldRev false; */
+
+		if( is_null( $this->mOldRev ) ) {
+			return false;
+		}
+
+		if ( $this->mOldRev ) {
+			$this->mOldPage = $this->mOldRev->getTitle();
+
+			$t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
+			$dateofrev = $wgLang->date( $this->mOldRev->getTimestamp(), true );
+			$timeofrev = $wgLang->time( $this->mOldRev->getTimestamp(), true );
+			$oldLink = $this->mOldPage->escapeLocalUrl( array(
+				'oldid' => $this->mOldid
+			) );
+			$oldEdit = $this->mOldPage->escapeLocalUrl( array(
+				'action' => 'edit',
+				'oldid' => $this->mOldid
+			) );
+			$this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t, $dateofrev, $timeofrev ) );
+
+			$this->mOldtitle = "<a href='$oldLink'>{$this->mOldPagetitle}</a>"
+			. " (<a href='$oldEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
+			// Add an "undo" link
+			$newUndo = $this->mNewPage->escapeLocalUrl( array(
+				'action' => 'edit',
+				'undoafter' => $this->mOldid,
+				'undo' => $this->mNewid
+			) );
+			$htmlLink = htmlspecialchars( wfMsg( 'editundo' ) );
+			$htmlTitle = $wgUser->getSkin()->tooltip( 'undo' );
+			if( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
+				$this->mNewtitle .= " (<a href='$newUndo' $htmlTitle>" . $htmlLink . "</a>)";
+			}
+
+			if( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
+				$this->mOldtitle = '<span class="history-deleted">' . $this->mOldPagetitle . '</span>';
+			} else if( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
+				$this->mOldtitle = '<span class="history-deleted">' . $this->mOldtitle . '</span>';
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Load the text of the revisions, as well as revision data.
+	 */
+	function loadText() {
+		if ( $this->mTextLoaded == 2 ) {
+			return true;
+		} else {
+			// Whether it succeeds or fails, we don't want to try again
+			$this->mTextLoaded = 2;
+		}
+
+		if ( !$this->loadRevisionData() ) {
+			return false;
+		}
+		if ( $this->mOldRev ) {
+			$this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
+			if ( $this->mOldtext === false ) {
+				return false;
+			}
+		}
+		if ( $this->mNewRev ) {
+			$this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
+			if ( $this->mNewtext === false ) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	/**
+	 * Load the text of the new revision, not the old one
+	 */
+	function loadNewText() {
+		if ( $this->mTextLoaded >= 1 ) {
+			return true;
+		} else {
+			$this->mTextLoaded = 1;
+		}
+		if ( !$this->loadRevisionData() ) {
+			return false;
+		}
+		$this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
+		return true;
+	}
+}
-- 
cgit v1.2.2