In the acknowledger for the bar-line-interface, a check to see if the
acknowledged grob contains the bar-line-interface is superfluous.
Instead, filter out SpanBar grobs (with a span-bar-interface check) in
the acknowledger so that SpanBars are not added to bars_ if more than
one Span_bar_engraver exists in a context.
Span_bar_engraver::acknowledge_bar_line (Grob_info i)
{
int depth = i.origin_contexts (this).size ();
- if (depth && Bar_line::has_interface (i.grob ()))
+ if (depth && !Span_bar::has_interface (i.grob ()))
{
Item *it = dynamic_cast<Item *> (i.grob ());
bars_.push_back (it);