Docs: move common files and factorize Texinfo macros

[lilypond.git] / lily / listener.cc

diff --git a/lily/listener.cc b/lily/listener.cc
index edc96bdf1c84aed5a51c69b87ae4914a125ebe77..c8202a9d345d6ef8d9d0fabe066d688cd380a5e6 100644 (file)
--- a/lily/listener.cc
+++ b/lily/listener.cc
@@ -10,6 +10,12 @@
 #include "ly-smobs.icc"
 #include "warn.hh"
 
+Listener::Listener ()
+{
+  target_ = 0;
+  type_ = 0;
+}
+
 Listener::Listener (const void *target, Listener_function_table *type)
 {
   target_ = (void *)target;
@@ -30,12 +36,13 @@ SCM
 Listener::mark_smob (SCM sm)
 {
   Listener *me = (Listener *) SCM_CELL_WORD_1 (sm);
-  (me->type_->mark_callback) (me->target_);
+  if (me->type_)
+    (me->type_->mark_callback) (me->target_);
   return SCM_EOL;
 }
 
 int
-Listener::print_smob (SCM s, SCM p, scm_print_state*)
+Listener::print_smob (SCM, SCM p, scm_print_state*)
 {
   scm_puts ("#<Listener>", p);
   return 1;