[XeTeX] XeTeX and DejaVU Sans Mono Kerning in Adobe Reader

[Bernhard Fisseni]

Good morning,

I am not sure whether this is a XeTeX bug, an Adobe Reader bug or a  
bug in the DejaVu Sans mono font, but maybe you can help me anyway.   
This problem only occurs if I use DejaVu Sans Mono with XeTeX/ 
xdvipdfmx and view the resulting PDF with Adobe Reader.  (I have not  
found any corresponding bug reports, but maybe this is a known issue,  
as DejaVu seems to be a very usual font.)

I used XeLaTeX[1] with xdvipdfmx to produce presentation slides for a  
course.  As monospaced font I used DejaVu Sans Mono. Now, if I open  
the resulting document in Adobe Reader[2], it seems to apply kerning  
to the monospaced passages (see the slide at http://www.uni-due.de/~hg0132/XeTeX-DejaVu.pdf 
, look at the dashes and "|"s; see also the attached rather minimal  
example, look at the "T.T," and the "|", but also the "wi").  This is  
rather unfortunate because it looks as if there are additional spaces  
where there should not be any (and students cannot be expected to see  
that this is a font issue because they are learning that such details  
can matter e.g. in regular expressions).

The problem does not occur if the file is viewed in any other viewer  
(any other viewer I tried: poppler/xpdf-based evince, xpdf, kpdf;  
Apple PDFKit-based Preview and Skim).  If I generate a PDF using  
DejaVu Sans Mono in OpenOffice.org or NeoOffice, it displays fine in  
Adobe Reader. With xdv2pdf, the PDF displays fine, too (however, I  
could not get the right page format for the presentation for all pages  
-- the first is different; and I would like to be able to compile the  
slides on Linux). If I use a different monospaced font (Monaco,  
Inconsolata), the PDF displays fine, as well (but then I still have to  
use DejaVu to get a ‘visible space’, which messes up the ‘monospacing’).

I'd be grateful for any hint.

Regards,
Bernhard


[1] Latest subversion version, but I also had the issue with earlier
versions, I must confess to being lazy about a bug(?) report.

[2] Teaching students to use a different PDF viewer is not really an
option. ;-|  And after all, PDF should be rather viewer independent.



RATHER MINIMAL EXAMPLE
======================


\documentclass{article}
\usepackage{xltxtra}
\setmonofont{DejaVu Sans Mono}

\begin{document}
\texttt{Kaffee|Tee? T.T,wie Typhus}
\end{document}