add head-direction to semi-tie-interface.

diff --git a/lily/semi-tie.cc b/lily/semi-tie.cc
index 96d4a07219ac88906d15f596b51b2711de9a2bab..80a56e4c74846e150515d7cbd952d312737e9716 100644 (file)
--- a/lily/semi-tie.cc
+++ b/lily/semi-tie.cc
@@ -23,6 +23,7 @@ ADD_INTERFACE(Semi_tie,
              "control-points "
              "direction "
              "details "
+             "head-direction "
              "note-head "
              "thickness "
              );