Index: EditPage.php
===================================================================
RCS file: /cvsroot/wikipedia/phase3/includes/EditPage.php,v
retrieving revision 1.142
diff -w -b -i -r1.142 EditPage.php
639c639
< 		global $wgOut, $wgUser, $wgTitle, $wgParser;
---
> 		global $wgOut, $wgUser, $wgTitle, $wgParser, $wgAllowDiffPreview, $wgEnableDiffPreviewPreference;
670a671,684
> 			# display preview with diff, if enabled
> 			$difftext = '';
> 			if ( $wgAllowDiffPreview && ( !$wgEnableDiffPreviewPreference || $wgUser->getOption('diffpreview') )) {
> 				require_once( "DifferenceEngine.php" );
> 				$oldtext = $this->mArticle->getContent(true);
> 				$newtext = $toparse;
> 				$oldtitle = wfMsg('currentrev');
> 				$newtitle = wfMsg('yourtext');
> 				
> 				if ($oldtext != wfMsg('noarticletext') || $newtext != '') {
> 					$difftext = DifferenceEngine::getDiff( $oldtext, $newtext, $oldtitle, $newtitle );
> 				}
> 			}
> 			
674a689,691
> 			if (!empty($difftext)) {
> 				$previewHTML .= '<br />' . $difftext;
> 			}