Issue with PDF printing via cairo library – Proposed Patch

[Tim-Philipp Müller]

Hi,

Due to an influx of spam user accounts on GitLab are restricted by
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Cheers
 Tim

On Fri, 2025-07-25 at 13:32 +0000, Vladimir Gribko wrote:
> 
> 
> Hello Luca Bacci,
>  
> Thank you for reviewing the proposed changes.
>  
> Today, I attempted to create a merge request but encountered an
> issue:
> I logged into gitlab.freedesktop.org using my GitHub account
> (vladgrind) and tried to fork the Cairo repository into my projects.
> However, I received the following warning:
>  
> "Limit reached. You cannot create projects in your personal
> namespace. Contact your GitLab administrator."
>  
> Could you please advise on how to proceed? Alternatively, would it be
> possible for one of the Cairo developers to add the changes into
> their branch for merging?
>  
> Thank you very much for your support.
>  
> Best regards,
> Vladimir.
>  
> 
> 
> From: Luca Bacci <luca.bacci982 at gmail.com>
> Sent: Wednesday, July 23, 2025 9:30 AM
> To: Vladimir Gribko <Vladimir.Gribko at cib.de>
> Cc: cairo at cairographics.org; Patrick Fritzsch
> <Patrick.Fritzsch at cib.de>
> Subject: [EXTERNAL] Re: Issue with PDF printing via cairo library –
> Proposed Patch
>  
> 
> 
> 
> 
> 
> 
> 
> You don't often get email fromluca.bacci982 at gmail.com. Learn why this
> is important [2] 
> 
> 
> 
> 
> 
> 
> 
> 
> Thanks, this looks like a sensible change. Could you open a Merge
> Request
> athttps://gitlab.freedesktop.org/cairo/cairo/-/merge_requests?
> 
>  
> 
> Best Regards,
> 
> Luca
>  
> 
> 
> Il giorno mar 22 lug 2025 alle ore 16:38 Vladimir Gribko
> <Vladimir.Gribko at cib.de> ha scritto:
> > 
> > 
> > 
> > Hello cairo developers,
> >  
> > I am a C++ developer at CIB software GmbH, and we use cairo for
> > rendering and printing PDF documents within our product, CIB pdf
> > toolbox 2.
> > Recently, we encountered an issue when printing certain PDF with
> > the "Microsoft Print to PDF" printer: the output PDF appeared
> > distorted.
> > We couldn't find a problem in our code, and for further testing we
> > printed this PDF, using the well-known open-source utility
> > pdftocairo: 
> >  
> > > pdftocairo.exe -print -printer "Microsoft Print to PDF" input.pdf
> > output.pdf
> >  
> > We observed the same result with pdftocairo and therefore suspected
> > a problem in the cairo code.
> >  
> > Upon analyzing the problem, we identified two issues within the
> > function _cairo_win32_printing_surface_paint_recording_pattern():
> >  
> > 1. The use of an uninitialized variable, is_subsurface.
> > 2. Displaced ClipPath for the pattern being printed, which leads to
> > the distorted output.
> >  
> > We have developed a patch addressing these two issues and would
> > like to propose it for inclusion in the cairo code.
> > Additionally, I have attached the minimized input.pdf and the
> > distorted output.pdf obtained with pdftocairo.
> > So, please review and share your feedback.
> > Thank you for your attention.
> >  
> > Best regards,
> > Vladimir Gribko.


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