Fix #943 (input/regression/slur-broken-trend.ly broken)

Fix #943 (input/regression/slur-broken-trend.ly broken)

* move after-line-breaking processing back into System::post_processing ()

[Patrick McCarty, 2010-02-21 21:09:54]

http://codereview.appspot.com/203054/diff/1/2
File lily/system.cc (right):

http://codereview.appspot.com/203054/diff/1/2#newcode310
lily/system.cc:310: {
Hi Neil,

I'm not really sure about the order of operations here, but I noticed something
else:

Removing the 'after-line-breaking callback from BarNumber also appears to fix
the problem.

Specifically, the slur regtest is fixed and "page-spacing-rehearsal-mark.ly" is
unaffected.

Is the 'after-line-breaking callback for BarNumber necessary?

[Neil Puttock, 2010-02-22 17:28:27]

On 2010/02/21 21:09:54, Patrick McCarty wrote:

> Is the 'after-line-breaking callback for BarNumber necessary?

I'm not quite sure; though it's unlikely anbody's going to change the BarNumber
stencil to a tall column (which would need the callback to prevent it running
off the top of the page), the regression tests seems to depend on the callback:
if you remove it, rehearsal marks, volte and metronome marks are placed too far
from staves.

[joeneeman, 2010-02-22 21:10:25]

http://codereview.appspot.com/203054/diff/1/2
File lily/system.cc (left):

http://codereview.appspot.com/203054/diff/1/2#oldcode193
lily/system.cc:193: }
For vertical positioning to work, it's important that after-line-breaking be
called before Page_layout_problem does its work. Can you check that this is
still the case?

[Neil Puttock, 2010-02-22 22:12:20]

On 2010/02/22 21:10:25, joeneeman wrote:

> For vertical positioning to work, it's important that after-line-breaking be
> called before Page_layout_problem does its work. Can you check that this is
> still the case?

The regression tests check out (though that's hardly surprising, considering all
this patch does is restore some code to its former position).

Doesn't Page_layout_problem come after the production of Paper_score objects? 
That's where the processing ultimately takes place (in
Paper_score::get_paper_systems ()).

[hanwenn, 2010-03-04 15:07:48]

If this restores code that was formerly working in some release this can go in,
but if this fixes a hairy issue, the change should at least document how the
hairy problem came about and why it fixes this.

[joeneeman, 2010-03-04 20:40:08]

Just for the record, I posted to lily-devel (because I wanted to attach a file
and I can't seem to do that here) to point out that this patch breaks
input/regression/page-spacing-rehearsal-mark.ly.

[Neil Puttock, 2010-03-04 21:31:25]

On 2010/03/04 20:40:08, joeneeman wrote:
> Just for the record, I posted to lily-devel (because I wanted to attach a file
> and I can't seem to do that here) to point out that this patch breaks
> input/regression/page-spacing-rehearsal-mark.ly.

Unfortunately, it didn't show up with `make check', so I assumed the patch
worked OK.