Re: [Groff] Re: Problem with devtag macros?

[Werner LEMBERG]

>> The  problem is that the .tag request confuses the
>> .br request.

I've now analyzed the problem.  Sorry for the long delay.

> I do not understand why the output of a tag-unaware device can
> depend on tags.  I still think it is a bug or a design problem.

The requests `.tag' and `.taga' insert a node, causing the problems
you experience with `.SP'.  From a user's point of view, it behaves
similarly to inserting `\&'.

> I have successfully used input line traps to fix this for my
> particular task (no drawing requests, multicolumn output and
> complicated nested diver- stions), but I couldn't derive a generic
> criteria to determine whether a .tag request has been called so it
> could be handled specially in .SP to stop it from generating excess
> vertical space...

It is not possible to find out the type of the last node in the line
node list.  However, if you say

  .vpt 0
  .DEVTAG-EO-H
  .br
  .sp -1
  .vpt 1

the vertical effect of .DEVTAG-EO-H is cancelled; this works just fine
with your example.  Can you try whether this works with your documents
as a patch to to mm also?


    Werner