Re: pdfroff in groff 1.23.0.rc3 changes compared to 1.22.4

[Dave Kemper]

On 4/5/23, Michał Kruszewski <mkru@protonmail.com> wrote:
> There are so many differences between pdfroff 1.22.4 <-> groff 1.22.4 and
> between groff 1.22.4 <-> 1.23.0rc3 that I think I am lost.

1.23 is definitely a quantum leap forward from 1.22.4.  There's a lot to digest!

> Secondly I have switched from groff 1.22.4 to groff 1.23.0rc3.
> However, the layout is now broken, as some of .sp and .bp in my document are
> ignored in the newer version.
> I do not see in man groff_ms any macros for page break or vertical space.
> I am attaching a little reproducer.

The missing page break you're seeing here is due to a combination of factors:
 - Immediately before the .bp, you call the .DE macro
 - The .DE macro was recently modified to invoke the .ns request.
 - When no-space mode (.ns) is in effect, a .bp is ignored.  (This is
long-established roff behavior.)

The .ns request was added to .DE to address a rendering issue with
multiple displays in a row.  (See http://savannah.gnu.org/bugs/?62688
for the full story.)  Your case appears to be an unintended side
effect.

The simplest solution is to turn off no-space mode yourself (using the
.rs request) before the call to .bp.  A more general solution for you
might be to write your own simple new-page macro that always does this
for you:

.de BP
.rs
.bp
..

I'll let Branden address whether his 62688 fix should be tweaked to
account for this.