From 679a4447b46ab448e75ec50c761da14ccf837d32 Mon Sep 17 00:00:00 2001
From: Claudio Costa <cstcld91@gmail.com>
Date: Thu, 3 Sep 2020 19:25:01 +0200
Subject: [PATCH] Fix error handling (#15392)

---
 services/filesstore/s3store.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/services/filesstore/s3store.go b/services/filesstore/s3store.go
index 42f7308127..468047553b 100644
--- a/services/filesstore/s3store.go
+++ b/services/filesstore/s3store.go
@@ -6,6 +6,7 @@ package filesstore
 import (
 	"bytes"
 	"context"
+	"errors"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -140,7 +141,8 @@ func (b *S3FileBackend) FileExists(path string) (bool, *model.AppError) {
 		return true, nil
 	}
 
-	if err.(s3.ErrorResponse).Code == "NoSuchKey" {
+	var s3Err s3.ErrorResponse
+	if errors.As(err, &s3Err); s3Err.Code == "NoSuchKey" {
 		return false, nil
 	}