Page breaks before @example

[Gavin Smith]

I was experimenting with adding a page break penalty at the start of
an @example, and some other display environments, because in material
like:

If you want to remove a preinstalled address@hidden completely before any of
its modes have been used,
@example
(unload-feature 'tex-site)
@end example
should accomplish that.

it looks better if there's no page break before the example. I've made
a test file to show this.

I managed to add a penalty at the start of the environment, but I
don't understand why there was actually a bonus for a page break in
the existing code. In \aboveenvbreak there is:

      % it's not a good place to break if the last penalty was \nobreak
      % or better ...
      \ifnum\lastpenalty<10000 \penalty-50 \fi

That \penalty-50 is a bonus. As far as I can tell that bonus has
always been there.

Any thoughts or guesses about whether it's a good idea, to discourage
or encourage page breaks before @examples?

I would guess that bonus is there to try to get an @example not to
span more than one page.

example-new-page.texi
Description: TeXInfo document

example-new-page.dvi
Description: TeX dvi file