Ticket #10172: 10172.diff

wp-includes/wp-db.php

@@ -396 +396 @@
          */
         function set_prefix($prefix) {
 
-                if ( preg_match('|[^a-z0-9_]|i', $prefix) )
+                if ( preg_match('|^[^a-z0-9_]*$|i', $prefix) )
                         return new WP_Error('invalid_db_prefix', /*WP_I18N_DB_BAD_PREFIX*/'Invalid database prefix'/*/WP_I18N_DB_BAD_PREFIX*/);
 
                 $old_prefix = $this->prefix;