Re: Footnotes: empty fill-lines in header & footer

[Mike Solomon]

On Mar 13, 2011, at 3:17 PM, Nicolas Sceaux wrote:

> Le 13 mars 2011 à 19:53, Nicolas Sceaux a écrit :
> 
>> Hi Mike,
>> 
>> First of all, thank you very much for your precious work on footnotes.
>> 
>> The following example demonstrates a strange behavior wrt footnotes:
>> 
>> %% For each empty \fill-line in header and footer markups,
>> %% footnotes together with separation line are added.
> 
> Actually the header markup has no impact, and the problem is not due to
> \fill-line, but to \column:
> 
> \paper {
>  %% no problem with \markup { \column { } }
>  oddFooterMarkup = \markup \column { }
> }
> 
> { \footnoteGrob #'NoteHead #'(1 . 2) "note" "footnote" c'' }
> 
> Nicolas
> 


AHH!!  Attack of the footnotes!!

I get the sense that this bug may have to do with the way that footers and/or 
markups work in general, not just the footnotes.  More precisely, the footnotes 
get attached to the footer via Page_layout_problem::add_footnotes_to_footer on 
line 98 of page-layout-problem.cc .  This is only ever called twice in the code 
- once for the dummy page used for configs (follow line 589 of page-breaking.cc 
to its logical conclusion) and once on line 553 of page-breaking.cc for the 
real deal.  When I use pretty prints in the code to compare the buggy output w/ 
the good output, the pretty prints in the footnote stream never change.

So, my guess is that the blank footer is printing multiple times, and thus, the 
non-blank footnote is tagging along with it.

What needs to be scrubbed, then, is this behavior.

As the behavior is correct for \markup { \column { } } and for \markup \column 
{ foo }, I think that it may be a parser issue &/or a markup interpretation 
issue &/or a footer creation issue.

At any rate, if there is someone who is conversant in markups and/or footers, 
I'd appreciate their taking this on.

The quick workaround, as already suggested by Nicolas, is simply to put \markup 
{ \column { } } anytime someone wants to use a blank column as the footer 
(which, admittedly, is esoteric, but as I am all about esoteric, I support 
someone's desire to do this).

Cheers,
MS