+ Stream_event *ev = start_events_[i];
+ string id = robust_scm2string (ev->get_property ("spanner-id"), "");
+ bool have_slur = false;
+ // Check if we already have a slur with the same spanner-id.
+ // In that case, don't create a new slur, but print a warning
+ for (vsize j = 0; j < slurs_.size (); j++)
+ have_slur = have_slur || (id == robust_scm2string (slurs_[j]->get_property ("spanner-id"), ""));
+
+ if (have_slur)
+ {
+ // We already have a slur, so give a warning and completely ignore
+ // the new slur.
+ ev->origin ()->warning (_ ("already have slur"));
+ start_events_.erase (start_events_.begin () + i);
+ }
+ }
+ for (vsize i = start_events_.size (); i--;)
+ {
+ Stream_event *ev = start_events_[i];
+ string id = robust_scm2string (ev->get_property ("spanner-id"), "");