Re: \tempo indication not printed

[Reinhold Kainhofer]

Am Donnerstag, 1. September 2011, 14:26:02 schrieb Neil Puttock:
> On 1 September 2011 13:06, Valentin Villenave <address@hidden> > > 
Unless *anyone* can explain what's going on therebelow, that is.
> 
> I think this is to do with the way barlines are treated by the
> engraver.  We have a special case for full-bar rests which ensures the
> tempo mark is aligned on the barline.  Unfortunately, it looks like
> it's preventing the mark from appearing in an empty bar.

BTW, this is a really minimal example:
\version "2.15.9"

{
  s1
  \tempo "Waldo"
  s1
}

The issue is that the moment after the \tempo command does not have any grobs 
where the tempo could be attached to. As soon as you change the s1 to a note 
or rest, or if you have clef/key/timesig change at the same moment as the 
\tempo, the tempo mark can be reparented. But it seems that the engraver 
misses the case that there are no other grobs at the same moment as the \tempo 
change. In that case, the tempo mark should be reparented to the barline...

The check currently is:
 if ([check for MM rest])
   ...
 else if (!support_)
   {
     if (Grob *mc = unsmob_grob (get_property ("currentMusicalColumn"))) 
       text_->set_parent (mc, X_AXIS);
     else if (Grob *cc = unsmob_grob (get_property ("currentCommandColumn")))
       text_->set_parent (cc, X_AXIS);
   }

So, the mark is always assigned the currentMusicalColumn as parent (confirmed 
by some debug statements). I think I read somewhere that later on the 
currentMusicalColumn is deleted if it does not contain any grobs... Am I 
wrong?


Cheers,
Reinhold
-- 
------------------------------------------------------------------
Reinhold Kainhofer, address@hidden, http://reinhold.kainhofer.com/
 * Financial & Actuarial Math., Vienna Univ. of Technology, Austria
 * http://www.fam.tuwien.ac.at/, DVR: 0005886
 * LilyPond, Music typesetting, http://www.lilypond.org