potential pstops (alternate) bug?

[Helge Blischke]

Christoph Litauer wrote:
> Hi,
> 
> I am running cups 1.1.23 using Helge Blischkes alternate pstops filter. 
>  From time to time we have problems printing documents where the 
> unfiltered (spooled) document could be printed but the filtered not.
> Most of the times this happens with documents containing images.
> 
> Now I tracked this down a little bit:
> I have a (large) pdf document printed with acrobat reader under windows 
> xp. The spooled data is printable, the output of pstops is not.
> 
> The original (spooled) postscript code contains lines like
> 
> (..........................................\^M.) show^M
> 
> These lines are converted to
> 
> (..........................................\
> .) show
> 
> As you can see, the carriage return character appearing in the middle of 
> a line has been converted to a newline. I think this is the reason why 
> documents containing pictures (binary data perhaps containing ^M's) are 
> unprintable after filtering.
> 
> What am I doing wrong? Is it really a bug?
> 

The "eaten" CRs should make no difference - usually they are
treated as ordinary line ends by the PS interpreter's scanner,
and a PostScript string that spans several lines is pretty legal.

I suspect there is an issue with DSC comments bracketing
binary data.

Try to configure your printer(s) an the windows side not to
use binary data.

If in doubt, please send me a sample file to have a look at.

Helge

-- 
Helge Blischke
Softwareentwicklung

H.Blischke at acm.org