From 959c94037c1e32f93b76b4648081f078587264c2 Mon Sep 17 00:00:00 2001
From: filipecosta90 <filipecosta.90@gmail.com>
Date: Sat, 29 Apr 2023 21:36:46 +0100
Subject: [PATCH] Enable specifying the protocol version on connection setup.
 Avoid CLIENT SETNAME command when using HELLO

---
 options.go | 12 ++++++++++++
 redis.go   |  6 ++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/options.go b/options.go
index a4af5884..d821b444 100644
--- a/options.go
+++ b/options.go
@@ -133,6 +133,11 @@ type Options struct {
 
 	// Enables read only queries on slave/follower nodes.
 	readOnly bool
+
+	// Protocol Version
+	// Redis version 6 and above supports two protocols: the old protocol, RESP2, and a new one introduced with Redis 6, RESP3.
+	// Default is 3.
+	ProtocolVersion int
 }
 
 func (opt *Options) init() {
@@ -199,6 +204,13 @@ func (opt *Options) init() {
 	case 0:
 		opt.MaxRetryBackoff = 512 * time.Millisecond
 	}
+
+	// If no ProtocolVersion is specified we default to 3.
+	// RESP3 has certain advantages since when the connection is in this mode,
+	// Redis is able to reply with more semantical replies.
+	if opt.ProtocolVersion != 2 && opt.ProtocolVersion != 3 {
+		opt.ProtocolVersion = 3
+	}
 }
 
 func (opt *Options) clone() *Options {
diff --git a/redis.go b/redis.go
index cae12f8c..f46ee76b 100644
--- a/redis.go
+++ b/redis.go
@@ -279,11 +279,13 @@ func (c *baseClient) initConn(ctx context.Context, cn *pool.Conn) error {
 	conn := newConn(c.opt, connPool)
 
 	var auth bool
+	var clientNameSet bool
 
 	// for redis-server versions that do not support the HELLO command,
 	// RESP2 will continue to be used.
-	if err := conn.Hello(ctx, 3, username, password, "").Err(); err == nil {
+	if err := conn.Hello(ctx, c.opt.ProtocolVersion, username, password, c.opt.ClientName).Err(); err == nil {
 		auth = true
+		clientNameSet = true
 	} else if !isRedisError(err) {
 		// When the server responds with the RESP protocol and the result is not a normal
 		// execution result of the HELLO command, we consider it to be an indication that
@@ -312,7 +314,7 @@ func (c *baseClient) initConn(ctx context.Context, cn *pool.Conn) error {
 			pipe.ReadOnly(ctx)
 		}
 
-		if c.opt.ClientName != "" {
+		if !clientNameSet && c.opt.ClientName != "" {
 			pipe.ClientSetName(ctx, c.opt.ClientName)
 		}