Fail gracefully when given bogus revisions

diff --git a/includes/DifferenceEngine.php b/includes/DifferenceEngine.php
index 767c736..93cec34 100644 (file)
--- a/includes/DifferenceEngine.php
+++ b/includes/DifferenceEngine.php
@@ -270,6 +270,9 @@ class DifferenceEngine {
                } else {
                        $this->newRev =& Revision::newFromTitle( $wgTitle );
                }
+               if( is_null( $this->newRev ) ) {
+                       return false;
+               }
                
                if( $this->newRev->isCurrent() ) {
                        $this->mPagetitle = htmlspecialchars( wfMsg( 'currentrev' ) );
@@ -290,6 +293,9 @@ class DifferenceEngine {
                        $this->oldRev =& $this->newRev->getPrevious();
                        $this->mOldid = $this->oldRev->getId();
                }
+               if( is_null( $this->oldRev ) ) {
+                       return false;
+               }
                        
                $this->mOldPage = $this->oldRev->getTitle();