From cc6209e8a011974ef25a5be53ccac8c59ff0414e Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Mon, 30 May 2022 09:41:26 +0300
Subject: [PATCH] [#1449] object/delete: Fix NPE in `collectChain`

`head.previous` method returns (nil, nil) if object has no previous
neighbor.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 pkg/services/object/delete/exec.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pkg/services/object/delete/exec.go b/pkg/services/object/delete/exec.go
index cfefd8ad..ab012ab3 100644
--- a/pkg/services/object/delete/exec.go
+++ b/pkg/services/object/delete/exec.go
@@ -153,8 +153,10 @@ func (exec *execCtx) collectChain() bool {
 			exec.status = statusOK
 			exec.err = nil
 
-			withPrev = true
-			prev = *p
+			withPrev = p != nil
+			if withPrev {
+				prev = *p
+			}
 		}
 	}