Bug#508528: texlive-base-bin: dvips without -j0 causes missing characters in output
retitle 508528 dvips should parse referenced PS images to determin
used fonts
severity 508528 wishlist
tags 508528 wontfix
thanks
On Mon, Dec 15, 2008 at 10:35 -0500, Mark T.B. Carroll wrote:
> Ralf Stubner <ralf.stubner@web.de> writes:
>
> > The problem is simply that dvips cannot interpret the included PS
> > image, since it does not contain a PS parser.
>
> Oh - the DVI format still includes uninterpreted PostScript (the
> included EPS figures)? Gosh. Now I come to look at xdvi's manpage I see
> that indeed it does seem to call things like Ghostscript when necessary.
DVI files can contain raw PS code (eg when using pstricks), but it can
be even worse. In the current case of an included image, the DVI file
only contains a reference to the PS file, and that reference is not
some sort of standard feature of DVI but done via a so called special
command. These special comamnds can contain basically anything and it
is left to the DVI processor what to do with them. Fortunately the
number of DVI processors isn't all that hugh nowerdays, and there is
quite some overlap in the supported specials. Still, a DVI file
produced for dvips will not come out correctly when processed with
dvipdfm. And quite a lot of PostScript trickery that shows up
correctly after running dvips is invisible in xdvi.
> > I would therefore suggest to either close this bug or retitleit to
> > "dvips should parse included PS images to determin used fonts",
> > lowering it to 'whishlist' and tagging it as 'wontfix'. What do you
> > think?
>
> That seems very reasonable. Given `wontfix' at the Debian side, would
> you be able to pass the wishlist item upstream? (Or is that done
> routinely anyway?) Given that the DVI format seems capable of including
> PostScript, and LaTeX-with-EPS to DVI to PostScript is a common usage
> case of dvips, it seems bizarre for it to be so eager to attempt an
> optimization it can't currently actually do safely.
I see no point in passing it upstream for several reasons. One is that
there is almost no development going on with respect to dvips. The
other is that this is a quite tricky problem. Basically you would need
a full PS interpreter to find out which glyphs from which fonts are
used in any referenced image.
> I would put the idea in your mind of adding to the Debian dvips
> manpage's -j option documentation a warning that it may not recognize
> that characters from included diagrams are needed. I'll leave that
> decision up to your judgment though. (-:
I will see if I come up a with some propper wording for this. Though
it does not belong to the -j option from my point of view. The problem
is that you request dvips to (partially) download the base PS fonts
but at the same time use a EPS file that requires one of these base PS
fonts without including it. I do not know where this sort of
information should be put ...
cheerio
ralf
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