From 0f40ae3ff2ef4df6d1fbac433e63362ee45683c8 Mon Sep 17 00:00:00 2001
From: fukua95 <fukua95@gmail.com>
Date: Mon, 9 Jun 2025 16:06:21 +0800
Subject: [PATCH] fix: check if the shard exists to avoid returning nil (#3396)

Signed-off-by: fukua95 <fukua95@gmail.com>
---
 ring.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/ring.go b/ring.go
index 8a004b8c..4da0b21a 100644
--- a/ring.go
+++ b/ring.go
@@ -405,7 +405,12 @@ func (c *ringSharding) GetByName(shardName string) (*ringShard, error) {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
 
-	return c.shards.m[shardName], nil
+	shard, ok := c.shards.m[shardName]
+	if !ok {
+		return nil, errors.New("redis: the shard is not in the ring")
+	}
+
+	return shard, nil
 }
 
 func (c *ringSharding) Random() (*ringShard, error) {