here is the correct fix for head (MF 1.3)

diff --git a/includes/Parser.php b/includes/Parser.php
index be98d71..b59ac6c 100644 (file)
--- a/includes/Parser.php
+++ b/includes/Parser.php
@@ -2094,12 +2094,15 @@ class Parser
                $valid = '0123456789-ABCDEFGHIJKLMNOPQRSTUVWXYZ';
 
                foreach ( $a as $x ) {
-                       if ( $x == '' ) continue;
                        $isbn = $blank = '' ;
                        while ( ' ' == $x{0} ) {
                                $blank .= ' ';
                                $x = substr( $x, 1 );
                        }
+                       if ( $x == '' ) { # blank isbn
+                               $text .= "ISBN $blank";
+                               continue;
+                       }
                        while ( strstr( $valid, $x{0} ) != false ) {
                                $isbn .= $x{0};
                                $x = substr( $x, 1 );