[#605] Fix panic when payload discard

Signed-off-by: Roman Loginov <r.loginov@yadro.com>

api/layer/object.go

@@ -525,10 +525,7 @@ func (n *Layer) objectPutAndHash(ctx context.Context, prm frostfs.PrmObjectCreat
 	})
 	res, err := n.frostFS.CreateObject(ctx, prm)
 	if err != nil {
-		if _, errDiscard := io.Copy(io.Discard, prm.Payload); errDiscard != nil {
+		n.payloadDiscard(ctx, prm.Payload)
-			n.reqLogger(ctx).Warn(logs.FailedToDiscardPutPayloadProbablyGoroutineLeaks, zap.Error(errDiscard))
-		}
-
 		return nil, err
 	}
 	return &data.CreatedObjectInfo{
@@ -540,6 +537,14 @@ func (n *Layer) objectPutAndHash(ctx context.Context, prm frostfs.PrmObjectCreat
 	}, nil
 }
 
+func (n *Layer) payloadDiscard(ctx context.Context, payload io.Reader) {
+	if payload != nil {
+		if _, errDiscard := io.Copy(io.Discard, payload); errDiscard != nil {
+			n.reqLogger(ctx).Warn(logs.FailedToDiscardPutPayloadProbablyGoroutineLeaks, zap.Error(errDiscard))
+		}
+	}
+}
+
 type logWrapper struct {
 	log *zap.Logger
 }

api/layer/object_test.go

@@ -49,3 +49,16 @@ func TestGoroutinesDontLeakInPutAndHash(t *testing.T) {
 	require.ErrorIs(t, err, expErr)
 	require.Empty(t, payload.Len(), "body must be read out otherwise goroutines can leak in wrapReader")
 }
+
+func TestNilPayloadPutAndHash(t *testing.T) {
+	tc := prepareContext(t)
+	prm := frostfs.PrmObjectCreate{
+		Filepath: tc.obj,
+		Payload:  nil,
+	}
+
+	expErr := errors.New("some error")
+	tc.testFrostFS.SetObjectPutError(tc.obj, expErr)
+	_, err := tc.layer.objectPutAndHash(tc.ctx, prm, tc.bktInfo)
+	require.ErrorIs(t, err, expErr)
+}