Wrong content behaviour on the pdf

[AlexP3]

Attach (recommended) or Link to PDF file here:
pdf.pdf

Configuration:

• Firefox 70.0.1 (64-bit)
• Microsoft Windows 10 Pro, 10.0.18362 N/A Build 18362
• PDF.js: 2.3.101 (Firefox console output)
• built in

Steps to reproduce the problem:
Drag and drop the pdf file in a firefox browser.

What is the expected behavior? (add screenshot)
Line on the first page should have start coordinates x=100, y=100.

I have checked on a Chrome and Adobe, works fine.

What went wrong? (add screenshot)
Line on the bottom of the first page has start coordinates x=0, y=0.

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

[timvandermeij]

I can reproduce this using Firefox 70.0.1 (64-bit, Linux). There are no warnings/errors in the console.

[THausherr]

This one does the transformation after the path has been set but before the draw. All PDFs I have seen do the transformation first. I could not find which way is correct by looking at the PDF specification.

[Snuffleupagus]

Duplicate of #10908