From eb090d3544cb755ed8bc30a401ceff69671546e7 Mon Sep 17 00:00:00 2001
From: buengese <buengese@protonmail.com>
Date: Wed, 20 Jan 2021 17:07:03 +0100
Subject: [PATCH] compress: check type assertion in SetTier - fixes #4941

---
 backend/compress/compress.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/backend/compress/compress.go b/backend/compress/compress.go
index ae12b4917..96ee53811 100644
--- a/backend/compress/compress.go
+++ b/backend/compress/compress.go
@@ -1225,8 +1225,8 @@ func (o *Object) Hash(ctx context.Context, ht hash.Type) (string, error) {
 // multiple storage classes supported
 func (o *Object) SetTier(tier string) error {
 	do, ok := o.Object.(fs.SetTierer)
-	mdo, ok := o.mo.(fs.SetTierer)
-	if !ok {
+	mdo, mok := o.mo.(fs.SetTierer)
+	if !(ok && mok) {
 		return errors.New("press: underlying remote does not support SetTier")
 	}
 	if err := mdo.SetTier(tier); err != nil {