From b2002ffc6d2129d3964470d90378662a426f1ae7 Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Thu, 20 May 2021 11:04:20 +0300
Subject: [PATCH] [#543] object/get: Fix potential NPE on request forwarder

Request forwarding callback should be called only if set since it is an
optional parameter. In GetRangeHash forwarder is never set.

Call `forwarder` function only if it is non-nil. Remove no longer needed
`hashOnly` option.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 pkg/services/object/get/exec.go | 12 +-----------
 pkg/services/object/get/get.go  |  2 +-
 pkg/services/object/get/util.go |  2 +-
 3 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/pkg/services/object/get/exec.go b/pkg/services/object/get/exec.go
index 140ece9f..4752e60b 100644
--- a/pkg/services/object/get/exec.go
+++ b/pkg/services/object/get/exec.go
@@ -38,7 +38,7 @@ type execCtx struct {
 
 	curOff uint64
 
-	head, hash bool
+	head bool
 
 	curProcEpoch uint64
 
@@ -71,12 +71,6 @@ func withPayloadRange(r *objectSDK.Range) execOption {
 	}
 }
 
-func hashOnly() execOption {
-	return func(c *execCtx) {
-		c.hash = true
-	}
-}
-
 func (exec *execCtx) setLogger(l *logger.Logger) {
 	req := "GET"
 	if exec.headOnly() {
@@ -152,10 +146,6 @@ func (exec *execCtx) headOnly() bool {
 	return exec.head
 }
 
-func (exec *execCtx) hashOnly() bool {
-	return exec.hash
-}
-
 func (exec *execCtx) netmapEpoch() uint64 {
 	return exec.prm.common.NetmapEpoch()
 }
diff --git a/pkg/services/object/get/get.go b/pkg/services/object/get/get.go
index d7f23011..c65bdfe1 100644
--- a/pkg/services/object/get/get.go
+++ b/pkg/services/object/get/get.go
@@ -41,7 +41,7 @@ func (s *Service) GetRangeHash(ctx context.Context, prm RangeHashPrm) (*RangeHas
 			hash: util.NewSaltingWriter(h, prm.salt),
 		})
 
-		if err := s.getRange(ctx, rngPrm, hashOnly()); err != nil {
+		if err := s.getRange(ctx, rngPrm); err != nil {
 			return nil, err
 		}
 
diff --git a/pkg/services/object/get/util.go b/pkg/services/object/get/util.go
index eb3316de..ba44e595 100644
--- a/pkg/services/object/get/util.go
+++ b/pkg/services/object/get/util.go
@@ -80,7 +80,7 @@ func (c *clientCacheWrapper) get(addr string) (getClient, error) {
 }
 
 func (c *clientWrapper) getObject(exec *execCtx) (*objectSDK.Object, error) {
-	if !exec.assembling && !exec.hashOnly() {
+	if !exec.assembling && exec.prm.forwarder != nil {
 		return exec.prm.forwarder(c.client)
 	}