From 3b80e0a41d3dcaa492da559f0669def34b5469ab Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Mon, 10 Mar 2014 16:28:18 +0100
Subject: [PATCH] Cluster: don't allow BY option of SORT as well.

There is the exception of a "constant" BY pattern that is used in order
to signal to don't sort at all. In this case no lookup is needed so it
is possible to support this case in Cluster mode.
---
 src/sort.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/sort.c b/src/sort.c
index 95c87cc0..fedf0cf3 100644
--- a/src/sort.c
+++ b/src/sort.c
@@ -248,7 +248,17 @@ void sortCommand(redisClient *c) {
             sortby = c->argv[j+1];
             /* If the BY pattern does not contain '*', i.e. it is constant,
              * we don't need to sort nor to lookup the weight keys. */
-            if (strchr(c->argv[j+1]->ptr,'*') == NULL) dontsort = 1;
+            if (strchr(c->argv[j+1]->ptr,'*') == NULL) {
+                dontsort = 1;
+            } else {
+                /* If BY is specified with a real patter, we can't accept
+                 * it in cluster mode. */
+                if (server.cluster_enabled) {
+                    addReplyError(c,"BY option of SORT denied in Cluster mode.");
+                    syntax_error++;
+                    break;
+                }
+            }
             j++;
         } else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
             if (server.cluster_enabled) {