[#1338] object: Fix range provider in Patch handler

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

pkg/services/object/patch/range_provider.go

@@ -30,6 +30,12 @@ type rangeProvider struct {
 var _ patcherSDK.RangeProvider = (*rangeProvider)(nil)
 
 func (r *rangeProvider) GetRange(ctx context.Context, rng *objectSDK.Range) io.Reader {
+	// Remote GetRange request to a container node uses an SDK-client that fails range validation
+	// with zero-length. However, from the patcher's point of view, such request is still valid.
+	if rng.GetLength() == 0 {
+		return &nopReader{}
+	}
+
 	pipeReader, pipeWriter := io.Pipe()
 
 	var rngPrm getsvc.RangePrm
@@ -61,3 +67,9 @@ func (r *rangeProvider) GetRange(ctx context.Context, rng *objectSDK.Range) io.R
 
 	return pipeReader
 }
+
+type nopReader struct{}
+
+func (nopReader) Read(_ []byte) (int, error) {
+	return 0, io.EOF
+}