- cancellation_ = make_item ("KeyCancellation", key_ev_ ? key_ev_->self_scm () : SCM_EOL);
- cancellation_->set_property ("old-accidentals", last);
- cancellation_->set_property ("c0-position",
- get_property ("middleCPosition"));
+ SCM restore = SCM_EOL;
+ SCM *tail = &restore;
+ for (SCM s = last; scm_is_pair (s); s = scm_cdr (s))
+ {
+ SCM new_alter_pair = scm_assoc (scm_caar (s), key);
+ Rational old_alter = robust_scm2rational (scm_cdar (s), 0);
+ if (new_alter_pair == SCM_BOOL_F
+ || extranatural
+ && (ly_scm2rational (scm_cdr (new_alter_pair)) - old_alter)*old_alter < Rational (0))
+ {
+ *tail = scm_cons (scm_car (s), *tail);
+ tail = SCM_CDRLOC (*tail);
+ }
+ }
+
+ if (scm_is_pair (restore))
+ {
+ cancellation_ = make_item ("KeyCancellation",
+ key_event_
+ ? key_event_->self_scm () : SCM_EOL);
+
+ cancellation_->set_property ("alteration-alist", restore);
+ cancellation_->set_property ("c0-position",
+ get_property ("middleCPosition"));
+ }