GitHub PDF print

Very often I create PDF-files with PDFcreator from webpages for documentation purposes. From the resulting PDF I then can copy/paste text for sending it in a mail or ask somewhere a question.

I'm trying to do the same from URL at no luck. The PDF itself is ok and readable but when I copy some text from it I get weird characters like this:

screenshot

I tried Chrome / Firefox, also in reader view, none give a decent result.

What's the reason for not being able to create a "normal" PDF from GitHub with PDFcreator? Does GitHub use special formatting? Is there a solution to overcome this and have a "normal" PDF from which copy/paste is possible?

The PDF from github (see URL above) is the first time ever giving that kind of copy/paste problem (see picture above). I can only conclude that somehow github is different. As said, the PDF itself looks ok, it's just copy/paste that is not ok. I tried several PDF-readers, always with the same result