[Groff] Re: begin page blues

[Miklos Somogyi]

On 19/02/2006, at 1:38 AM, Miklos Somogyi wrote:

> Dear Experts,
>
> There's something that drives me crazy.
>
> If I start a page with something indented, it gets printed 1v lower  
> than otherwise.
> What is this "first line is different" thing?
> Can you save me from the asylum (or vice versa)?
>
> Miklos
>
> PS: I use the "me" macros and have tried .br and .rs with no luck.
----------------------------------------

PS: Sorry, I've found out that this is not an indentation problem after 
all.
There is a "unlawful" space that produces a linefeed when the indent is 
defined.

My groff file defines this an' that, calls .bp, calls a macro \Y[grid] 
that draws a grid in PS
to check out the layout. Then comes text with/without indentation.

The unlawful space seems to come from the grid macro and the problem 
can be solved with .sp -1
after the \Y[grid] call.
However, it would be good to know the how and why of this space 
(bug/feature).
Especially that there could be cases with no such easy solution.

Here's an artificial example just to see the extra space at work:

.vs  0.85c
.ps 20
.ft CR
.sp 10
Hello1
\X'ps: exec 1 0 0 setrgbcolor'
Hello2
Hello3
\X'ps: exec 0 0 0 setrgbcolor'
.br
Hello1 Hello2 Hello3
.\"
.ex

Here the red Hello2 Hello3 are one space to the right of the black ones.
Does anyone know the how and why of this space?

Thanks

Miklos