From da76af187fbe86da0edd2e1bd5c25d9d4a45738c Mon Sep 17 00:00:00 2001
From: chrislu <chris.lu@gmail.com>
Date: Fri, 4 Mar 2022 22:36:01 -0800
Subject: [PATCH] mount: avoid possible index out of bounds error

---
 weed/filer/reader_cache.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/weed/filer/reader_cache.go b/weed/filer/reader_cache.go
index 4f2c52303..bce97cc49 100644
--- a/weed/filer/reader_cache.go
+++ b/weed/filer/reader_cache.go
@@ -183,6 +183,10 @@ func (s *SingleChunkCacher) readChunkAt(buf []byte, offset int64) (int, error) {
 	s.RLock()
 	defer s.RUnlock()
 
-	return copy(buf, s.data[offset:]), s.err
+	if s.err != nil {
+		return 0, s.err
+	}
+
+	return copy(buf, s.data[offset:]), nil
 
 }