[XeTeX] XeTeXpdffile positions differently on MacOS and Linux

[Paul Howson]

A strange problem is occurring when using \XeTeXpdffile to include PDF  
files with smallish dimensions -- e.g. 0.41 cm × 0.48 cm.

The included PDFs are being positioned differently on MacOS and Linux.

Background: We are using XETEX to generate reports for a web  
application. Small graphics used within the reports are included as  
PDF files via \XeTeXpdffile. Development of the report formats is  
being done on MacOS (Leopard) and the reports are being deployed on a  
Linux system where they are generated on the fly for a web application.

I believe we have exactly the same XETEX installation on both MacOS  
and Linux and that both are using the xdvipdfmx post-processor for  
generating the output PDFs.

Exactly the same PDF files are being included on both platforms.

So the differences in position must be due to some platform-specific  
difference in (i) how the bounding box or crop box or whatever box  
information is extracted from the PDFs AND/OR (ii) how xdvipdfmx  
positions the included PDFs.

Would Jonathan have any insights into these mechanisms and why there  
should be differences between platforms.

I'm surprised by this behaviour since everything else about XETEX,  
including Opentype font behaviour, seems to work identically (as one  
should expect).

Paul Howson
Queensland Australia