Re: [Groff] .br after .box *invariably* generates an output line?

[Jim Avera]

> > groff -Tascii <<'EOF'
> > .nf
>  ^^^
> This instruction causes the empty line.  Just try to insert three
> `.br' lines to get three line breaks.
> [snip]
> Only use .nf while replaying a diversion (to avoid reformatting), not
> while defining it.

Thanks for responding... I'm still not quite getting it, and hoping you can find
another way to explain.   A .br doesn't -create- a pending line, it just flushes
a pending partial line if there is one (right?)   Inserting three .br in a row
does not create three blank lines.  Clearly something besides a break has to 
happen
to create a pending line.

What I don't get is where the "pending" line comes from in a diversion which
contains absolutely no text at all, just a solitary ".br".  See example below.
 
The final .br is necessary to capture the last partial line _if_ there is one.
But if there is _not_ anything formatted before the .br, why does the .br
output a line anyway?  What puts something into the pending buffer?

groff -Tascii <<'EOF'
.box xxx
.\"There is nothing here, so I expected nothing in the diversion
.br
.box
.nf
.xxx
After the box.
EOF

=>(blank line)
  After the box.

Thanks again for your help.
-Jim