From 3b420034bb692eb871f914c1a90b556c86c3a9eb Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Mon, 25 Feb 2019 16:40:58 +0100
Subject: [PATCH] RESP3: allow HELLO to be used with version = 2.

---
 src/networking.c | 11 ++---------
 src/server.h     |  1 +
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/src/networking.c b/src/networking.c
index e46e1b7fa..37d648577 100644
--- a/src/networking.c
+++ b/src/networking.c
@@ -2034,13 +2034,6 @@ void helloCommand(client *c) {
         return;
     }
 
-    /* Switching to protocol v2 is not allowed. But we send a specific
-     * error message in this case. */
-    if (ver == 2) {
-        addReplyError(c,"Switching to RESP version 2 is not allowed.");
-        return;
-    }
-
     /* At this point we need to be authenticated to continue. */
     if (!c->authenticated) {
         addReplyError(c,"-NOAUTH HELLO must be called with the client already "
@@ -2050,8 +2043,8 @@ void helloCommand(client *c) {
         return;
     }
 
-    /* Let's switch to RESP3 mode. */
-    c->resp = 3;
+    /* Let's switch to the specified RESP mode. */
+    c->resp = ver;
     addReplyMapLen(c,7);
 
     addReplyBulkCString(c,"server");
diff --git a/src/server.h b/src/server.h
index 994952654..0e754e911 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1737,6 +1737,7 @@ void ACLInit(void);
 #define ACL_DENIED_CMD 1
 #define ACL_DENIED_KEY 2
 int ACLCheckUserCredentials(robj *username, robj *password);
+int ACLAuthenticateUser(client *c, robj *username, robj *password);
 unsigned long ACLGetCommandID(const char *cmdname);
 user *ACLGetUserByName(const char *name, size_t namelen);
 int ACLCheckCommandPerm(client *c);