Safety: there might not be any indexes to use

lib/adapters/redis.js

@@ -159,7 +159,7 @@ BridgeToRedis.prototype.all = function all(model, filter, callback) {
         var indexes = pi[0];
         var noIndexes = pi[1];
 
-        if (indexes.length) {
+        if (indexes && indexes.length) {
             cmd = 'SINTER "' + indexes.join('" "') + '"';
             if (noIndexes.length) {
                 log(model + ': no indexes found for ', noIndexes.join(', '),