Default region if endpoint specified

s3/s3.go

@@ -732,10 +732,14 @@ func (r *Replica) Init(ctx context.Context) (err error) {
 	// Endpoints are typically used for non-S3 object stores and do not
 	// necessarily require a region.
 	region := r.Region
-	if region == "" && r.Endpoint == "" {
+	if region == "" {
+		if r.Endpoint == "" {
 			if region, err = r.findBucketRegion(ctx, r.Bucket); err != nil {
 				return fmt.Errorf("cannot lookup bucket region: %w", err)
 			}
+		} else {
+			region = "us-east-1" // default for non-S3 object stores
+		}
 	}
 
 	// Create new AWS session.