From c275010fffe03ac83c5636ed464d7e57f7d96005 Mon Sep 17 00:00:00 2001
From: Madelyn Olson <34459052+madolson@users.noreply.github.com>
Date: Mon, 24 Jan 2022 22:08:57 -0800
Subject: [PATCH] Correctly handle minimum arity checks in scripts (#10171)

Correctly handle variable arity checks in scripts
---
 src/script.c             | 2 +-
 tests/unit/scripting.tcl | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/script.c b/src/script.c
index ded531e14..14a64b961 100644
--- a/src/script.c
+++ b/src/script.c
@@ -284,7 +284,7 @@ void scriptKill(client *c, int is_eval) {
 }
 
 static int scriptVerifyCommandArity(struct redisCommand *cmd, int argc, sds *err) {
-    if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) || (argc < cmd->arity))) {
+    if (!cmd || ((cmd->arity > 0 && cmd->arity != argc) || (argc < -cmd->arity))) {
         if (cmd)
             *err = sdsnew("Wrong number of args calling Redis command from script");
         else
diff --git a/tests/unit/scripting.tcl b/tests/unit/scripting.tcl
index 9e1246355..f16555350 100644
--- a/tests/unit/scripting.tcl
+++ b/tests/unit/scripting.tcl
@@ -598,6 +598,11 @@ start_server {tags {"scripting"}} {
         set e
     } {ERR Number of keys can't be negative}
 
+    test {Scripts can handle commands with incorrect arity} {
+        assert_error "*Wrong number of args calling Redis command from script" {run_script "redis.call('set','invalid')" 0}
+        assert_error "*Wrong number of args calling Redis command from script" {run_script "redis.call('incr')" 0}
+    }
+
     test {Correct handling of reused argv (issue #1939)} {
         run_script {
               for i = 0, 10 do