Issue 4718/2: Let transpose_music_list act defensively for non-Prob members

diff --git a/lily/music-sequence.cc b/lily/music-sequence.cc
index 049300442bf0acad42e7a575080f7f93a7618c90..644ba9beb727e5982603ba69485a1c4dfdda15b2 100644 (file)
--- a/lily/music-sequence.cc
+++ b/lily/music-sequence.cc
@@ -30,7 +30,8 @@ void
 transpose_music_list (SCM lst, Pitch rq)
 {
   for (SCM s = lst; scm_is_pair (s); s = scm_cdr (s))
-    unsmob<Prob> (scm_car (s))->transpose (rq);
+    if (Prob *p = unsmob<Prob> (scm_car (s)))
+      p->transpose (rq);
 }
 
 Moment