Fix sentence_pos handling

Change-Id: Ib9f5c0bf8bb06d53dec72437c7f337c749658605
diff --git a/token_writer_test.go b/token_writer_test.go
index 82baa69..a27ae1c 100644
--- a/token_writer_test.go
+++ b/token_writer_test.go
@@ -84,4 +84,14 @@
 
 	matStr = w.String()
 	assert.Equal("1 5 5 6\n1 6\n0 3 3 4\n0 4\n", matStr)
+
+	//
+	// Write sentence offsets without token offsets
+	tws = NewTokenWriter(w, SENTENCE_POS|NEWLINE_AFTER_EOT)
+
+	w.Reset()
+	mat.TransduceTokenWriter(strings.NewReader("\nThis.\x0a\x04\nAnd.\n\x04\n"), tws)
+
+	matStr = w.String()
+	assert.Equal("1 6\n0 4\n", matStr)
 }