MDL-12542 - backup_todb not called on restore on date before it is inserted into mdl_user. This would cause a backup from a pre 1.7 site (or a pre 1.7 that has been upgraded to 1.9) to a 1.9 fresh install, to fail sometimes. Backported from MOODLE_19_STABLE.

backup/restorelib.php

@@ -1418,15 +1418,23 @@
             //in backup_ids->info will be the real info (serialized)
             $info = restore_read_xml_users($restore,$xml_file);
         }
-
+        
         //Now, get evey user_id from $info and user data from $backup_ids
         //and create the necessary records (users, user_students, user_teachers
         //user_course_creators and user_admins
         if (!empty($info->users)) {
             //For each user, take its info from backup_ids
             foreach ($info->users as $userid) {
-                $rec = backup_getid($restore->backup_unique_code,"user",$userid); 
+                $rec = backup_getid($restore->backup_unique_code,"user",$userid);
                 $user = $rec->info;
+                foreach (array_keys(get_object_vars($user)) as $field) {
+                    if (!is_array($user->$field)) {
+                        $user->$field = backup_todb($user->$field);
+                        if (is_null($user->$field)) {
+                            $user->$field = '';
+                        }
+                    }
+                }
 
                 //Now, recode some languages (Moodle 1.5)
                 if ($user->lang == 'ma_nt') {