Re: [Groff] Difference in Groff 1.19

[Werner LEMBERG]

> It seems that if you include pic code within a diversion which is
> preceded by a ".vs 0" when you output the diversion you must set
> ".vs 0" again before you output.  On the other hand if the pic code
> is preceded by ".vs 0.001p" (instead of zero) the value of 'vs' can
> be anything when you output the diversion and have no effect.

This is correct.  `.vs 0' isn't saved in a diversion since it doesn't
result explicitly in a vertical motion.  I'll document this special
case.  [BTW, instead of `.vs 0.001p' you should rather say `.vs 1u'
to get the smallest possible amount.]

Actually it wasn't allowed to have `.vs 0' at all before version 1.19:
You got a warning `vertical spacing must be zero or negative' (or
something like this), and groff automatically uses `.vs 1u' instead.

Another reason to use `-ww' :-)

> Using ".vs 0" before pic code can be quite useful, it makes accurate
> positioning of lines on the page much easier.

I use it all the time.


    Werner