From 8d8755c7b56069646ab0bd02e46652bfee19fcd1 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Tue, 6 Mar 2018 12:55:41 +0100
Subject: [PATCH] CG: throw an error if XREADGROUP is used without GROUP.

---
 src/t_stream.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/t_stream.c b/src/t_stream.c
index a2404244..e2908d2c 100644
--- a/src/t_stream.c
+++ b/src/t_stream.c
@@ -1131,6 +1131,13 @@ void xreadCommand(client *c) {
         return;
     }
 
+    /* If the user specified XREADGROUP then it must also
+     * provide the GROUP option. */
+    if (xreadgroup && groupname == NULL) {
+        addReplyError(c,"Missing GROUP option for XREADGROUP");
+        return;
+    }
+
     /* Parse the IDs and resolve the group name. */
     if (streams_count > STREAMID_STATIC_VECTOR_LEN)
         ids = zmalloc(sizeof(streamID)*streams_count);