Index: apachesolr.index.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/apachesolr/apachesolr.index.inc,v
retrieving revision 1.1.2.18
diff -u -p -r1.1.2.18 apachesolr.index.inc
--- apachesolr.index.inc	17 Dec 2009 16:36:10 -0000	1.1.2.18
+++ apachesolr.index.inc	22 Dec 2009 15:38:28 -0000
@@ -86,8 +86,9 @@ function apachesolr_node_to_document($ni
       $document->language = $node->language;
     }
     else {
-      // 'zxx' is the language-neutral code in Drupal 7.
-      $document->language = 'zxx';
+      // 'und' is the language-neutral code in Drupal 7.
+      // Note - this was changed from 'zxx'.
+      $document->language = 'und';
     }
     $document->body = apachesolr_clean_text($text);
     $document->type  = $node->type;
Index: apachesolr_search.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/apachesolr/apachesolr_search.module,v
retrieving revision 1.1.2.6.2.125
diff -u -p -r1.1.2.6.2.125 apachesolr_search.module
--- apachesolr_search.module	17 Dec 2009 16:37:39 -0000	1.1.2.6.2.125
+++ apachesolr_search.module	22 Dec 2009 15:38:28 -0000
@@ -756,9 +756,9 @@ function apachesolr_search_language_name
     if (function_exists('locale_language_list')) {
       $list = locale_language_list();
     }
-    $list['zxx'] = t('Language neutral');
-    // TODO - remove this line - only present for rc3 to rc4 update.
-    $list['[* TO *]'] = $list['zxx'];
+    $list['und'] = t('Language neutral');
+    // TODO - remove this line - only present for rc4 update.
+    $list['zxx'] = $list['und'];
   }
   return ($lang && isset($list[$lang])) ? $list[$lang] : $lang;
 }