Re: [groff] PDF problems - see attached file

[Robert D. Goulding]

On Wed, 22 May 2002, Christian Jensen wrote:

> On Tue, 21 May 2002, Robert D. Goulding wrote:
>
> > So could
> > you try:
> >
> > 1: Looking at the the .ps and .pdf files to check that they do look as I
> > describe, and that this is not an artifact of my system.
>
> Postscript file looks fine. The .pdf file looks wrong in Acrobat Reader
> (page 2), but ok in xpdf.
>
> > 2: Processing the .ps file with whatever version of gs you're using (and
> > Distiller?) to see if the fault is with my release of Ghostscript.
>
> GNU Ghostscript 6.51 (2001-03-28) produces a fine .pdf file from your .ps
> file. Seems the problem is somewhere in the combination of your gs version
> and Acrobat Reader?

Christian - thanks for testing it out.  I compiled and installed AFPL gs
7.04, and got exactly the same results.  You're right that the pdf file
looks fine in xpdf, but this isn't *just* an Acrobat problem, because it
also looks wrong in gv -- and (as I found after more experimentation) it
prints badly both in Acrobat and ghostscript (though, again, xpdf will
print to file with the ligatures correct).  It *seems* to me that this is
a bug with grops; something about its output cannot be handled by the 7.0x
branch of Ghostscript.  To summarize:

1) groff's postscript output can be distilled to pdf using the 6.x branch
of ghostscript without problem.

2) The 7.x branch, however, distills it incorrectly.  f-ligatures are
wrong (mis-spaced) from the *second* page of the pdf file.  This is so,
even though the postscript file can be viewed and printed correctly in
ghostscript.

3) These errors are apparent both to Acrobat Reader and to gv.  They
affect both on-screen viewing and printing.

4) The pdf file appears OK under xpdf, and prints to file correctly.

5) This problem seems to be groff-specific (or rather, grops-specific).
I tried distilling, by ps2pdf, a postscript file created by dvips and all
the ligatures appeared correctly.