From 0816b8fadd3cba0e49418452842f0d5c97a2040f Mon Sep 17 00:00:00 2001
From: Yossi Gottlieb <yossigo@gmail.com>
Date: Tue, 18 Aug 2020 17:13:09 +0300
Subject: [PATCH] Module API: Fail ineffective auth calls.

The client pointed to by the module context may in some cases be a fake
client. RM_Authenticate*() calls in this case would be ineffective but
appear to succeed, and this change fails them to make it easier to catch
such cases.

(cherry picked from commit 82866776d0c26f17043f9c1b0f0f5f48660e6848)
---
 src/module.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/module.c b/src/module.c
index bfe7d6886..65d22b713 100644
--- a/src/module.c
+++ b/src/module.c
@@ -5638,6 +5638,11 @@ static int authenticateClientWithUser(RedisModuleCtx *ctx, user *user, RedisModu
         return REDISMODULE_ERR;
     }
 
+    /* Avoid settings which are meaningless and will be lost */
+    if (!ctx->client || (ctx->client->flags & CLIENT_MODULE)) {
+        return REDISMODULE_ERR;
+    }
+
     moduleNotifyUserChanged(ctx->client);
 
     ctx->client->user = user;