Lines vanish when printing on MacOS

When printing the border.fo example (converted to PDF from Apache FOP) to a 4x6 printer on a Mac, some of the lines vanish.

• The behavior does not occur on a A4 or US Letter document.
• The behavior varies slightly depending on rendering hints.
• The behavior is not reproducible on Linux
• This problem has been discussed – in part – on the mailing list here: https://lists.apache.org/thread/nb9vsfx2gd8j37mrnlbbj0vqy6wrwt88

Attached is a sample project which reproduces this problem:

fop.zip

To run the example:

1. Install a PDF printer on the Mac
2. Extract fop.zip and run it using maven: 

mvn compile && mvn exec:java

Expected:

Actual:

In the field, this issue may be common in scenarios where labels are obtained from shipping companies that use Apache FOP for creating the PDFs and are then printed using PDFBOX (e.g. PitneyShip).  At time of writing this, the issue seems to be specific to MacOS.