Build: Invoke python -tt throughout (issue 1707).

[lilypond.git] / lily / scheme-engraver.cc

diff --git a/lily/scheme-engraver.cc b/lily/scheme-engraver.cc
index cde829a60788bec5b140942dad26a6fd75168184..1b1aad924ac1efd10e3bb2c19148646572ca70c2 100644 (file)
--- a/lily/scheme-engraver.cc
+++ b/lily/scheme-engraver.cc
@@ -186,10 +186,19 @@ void mark_listen_closure (void *target)
   scm_gc_mark ((SCM)target);
 }
 
+static
+bool equal_listen_closure (void *a, void *b)
+{
+  SCM target_a = (SCM) a;
+  SCM target_b = (SCM) b;
+
+  return ly_is_equal (target_a, target_b);
+}
+
 Listener_function_table listen_closure
 =
 {
-  call_listen_closure, mark_listen_closure
+  call_listen_closure, mark_listen_closure, equal_listen_closure
 };
 
 /* static */