From 6cd7a09b225902ecb92c6851e0aad63d8331ac3e Mon Sep 17 00:00:00 2001
From: Vladimir Mihailenco <vladimir.webdev@gmail.com>
Date: Fri, 16 Dec 2016 14:05:21 +0200
Subject: [PATCH] Use first slot/shard when key is not defined.

---
 cluster.go | 17 +++++++++--------
 ring.go    |  3 ---
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/cluster.go b/cluster.go
index 5a8d25c..b898c0d 100644
--- a/cluster.go
+++ b/cluster.go
@@ -258,10 +258,10 @@ func newClusterState(nodes *clusterNodes, slots []ClusterSlot) (*clusterState, e
 
 func (c *clusterState) slotMasterNode(slot int) (*clusterNode, error) {
 	nodes := c.slotNodes(slot)
-	if len(nodes) == 0 {
-		return c.nodes.Random()
+	if len(nodes) > 0 {
+		return nodes[0], nil
 	}
-	return nodes[0], nil
+	return c.nodes.Random()
 }
 
 func (c *clusterState) slotSlaveNode(slot int) (*clusterNode, error) {
@@ -364,15 +364,16 @@ func (c *ClusterClient) state() *clusterState {
 }
 
 func (c *ClusterClient) cmdSlotAndNode(state *clusterState, cmd Cmder) (int, *clusterNode, error) {
+	if state == nil {
+		node, err := c.nodes.Random()
+		return 0, node, err
+	}
+
 	cmdInfo := c.cmds[cmd.arg(0)]
 	firstKey := cmd.arg(cmdFirstKeyPos(cmd, cmdInfo))
-	if firstKey == "" || cmdInfo == nil {
-		node, err := c.nodes.Random()
-		return -1, node, err
-	}
 	slot := hashtag.Slot(firstKey)
 
-	if cmdInfo.ReadOnly && c.opt.ReadOnly {
+	if cmdInfo != nil && cmdInfo.ReadOnly && c.opt.ReadOnly {
 		if c.opt.RouteByLatency {
 			node, err := state.slotClosestNode(slot)
 			return slot, node, err
diff --git a/ring.go b/ring.go
index 356684f..aff019d 100644
--- a/ring.go
+++ b/ring.go
@@ -267,9 +267,6 @@ func (c *Ring) shardByName(name string) (*ringShard, error) {
 func (c *Ring) cmdShard(cmd Cmder) (*ringShard, error) {
 	cmdInfo := c.cmdInfo(cmd.arg(0))
 	firstKey := cmd.arg(cmdFirstKeyPos(cmd, cmdInfo))
-	if firstKey == "" {
-		return c.randomShard()
-	}
 	return c.shardByKey(firstKey)
 }