Re: Free documents using non-free fonts - can they be in main?

[Frank Küster <frank@debian.org>]

Bas Zoetekouw <bas@debian.org> wrote:

> Hi Frank!
>
> You wrote:
>
>> I'm wondering whether a document that's licensed under a DFSG-free
>> license, with TeX/sgml/whatever sources available and all, may use
>> non-free fonts.  For example, the LaTeX source would contain
>> \usepackage{lucidabr}
>> and you'd be able to create the document from that source only if you
>> have either the commercial or otherwise non-free font installed, or you
>> replace/remove that line.  Assuming that the original author has the
>> right to distribute and let re-distribute PDF files using that font
>> without limits, would it be okay for main to distribute the compiled
>> document (PDF) in the binary package, and the sources in the source
>> package?
>
> I think not.  AFAIK, the binaries in main must be built from the sources
> in main, which wouldn't be possible in the case you're describing.
> 
> What's the problem with just using the normal Concrete TeX fonts?

That's not the point.  In tetex-doc, we generally do *not* build the
documentation files from source, but instead use the ones included in
the orig.tar.gz, which in turn includes the author-provided versions
from CTAN.  There are several reasons for that, some of which are

- tetex-base would have to build-depend on tetex-bin if we rebuild the
  documentation

- we'd have to merge the upstream texmf.tar.gz (=tetex-base source
  package) and texmfsrc.tar.gz (=tetex-src source package) into one
  orig.tar.gz 

- There's no automated way to reproduce the documentation exactly as the
  author wants it, and once we would establish one, there would be no
  way to detect whether a new upstream version changed that.

  The reason for this is that building (La)TeX documentation

  * depends on the right number and order of commands to be executed,
    which one has to find by trial and error (it's very rare that
    authors upload Makefiles, since usually they aren't needed much)

  * depends on settings in local configuration files, which may differ
    from package author to package author and from version to version.

  So the author of a LaTeX package generates the documentation, looks at
  it, adjusts their local configuration if necessary, and uploads the
  package sources  and the documentation PDF (CTAN requires this AFAIK),
  but not local configuration files.  I assume the CTAN admins would
  reject uploads that include configuration files like ltxdoc.cfg,
  because it would make CTAN's search facilities unusable for that
  file. 

  As a consequence, you can't be sure to get the same document by simply
  running pdflatex over the source file.

So, since we don't rebuild the documentation anyway, we just ensure[1]
that the files we include have a free license, and that the source is
complete. 

So in the case of a document using a non-free font, it would be trivial
to "free" its source by simply commenting the line in the source.  I'd
rather avoid that, because I think it bloats the diff.gz without adding
any value, but I wouldn't care much.

But the important question is whether we can distribute that *existing*
document in main.

Regards, Frank


Footnotes: 
[1]  Read: are about to ensure, see http://bugs.debian.org/345604

-- 
Frank Küster
Single Molecule Spectroscopy, Protein Folding @ Inst. f. Biochemie, Univ. Zürich
Debian Developer (teTeX)