From 70ffa8ce5c6510bd7bf257a477e684d9a32ec1ac Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Tue, 18 Mar 2025 21:37:06 +0100
Subject: [PATCH] Fix VADD_CASReply() NULL reference on ID mismatch.

This bug was fixed thanks to the kind help of Dvir Dukhan
(@DvirDukhan) that found it and provided useful context.
---
 vset.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/vset.c b/vset.c
index 3be8e2f9e..7ccd6dae3 100644
--- a/vset.c
+++ b/vset.c
@@ -340,7 +340,8 @@ int VADD_CASReply(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
          * the other insert won. We don't even start a threaded VADD
          * if this was an udpate, since the deletion of the element itself
          * in order to perform the update would invalidate the CAS state. */
-        if (RedisModule_DictGet(vset->dict,val,NULL) != NULL) vset = NULL;
+        if (vset && RedisModule_DictGet(vset->dict,val,NULL) != NULL)
+            vset = NULL;
     }
 
     if (vset == NULL) {