SVG files rendered at a completely wrong size on Sphinx 9

[dkonigsberg]

When I run SimplePDF on Linux, the SVG graphics in the output all look fine. However, when I run it on macOS, those same graphics are sized wildly wrong.

Here's one side-by-side comparison, with Linux on the top and macOS on the bottom:

I've also attached the raw SVG here for reference:

This is not the worst example, but it is the easiest one to show in a simple side-by-side comparison.

Now I'm pretty sure the actual underlying libraries used to do the rendering aren't the same between both platforms, so if there's anything you'd like me to run/check to provide more information I certainly can. But I suspect this may be a case where Linux is scaling it as appropriate to the document and macOS is scaling it based on some metadata in the SVG file.

[dkonigsberg]

Digging into this a little more, I think the issue is that WeasyPrint on macOS is completely ignoring SVG size instructions from the HTML size, and just taking the ones in the SVG file itself verbatim. And those are kinda all over the map in my doc project, because they never mattered before. But if I explicitly add "width" and "height" attributes to the root "" element, rendering size becomes sane.

What's weird about this is that I do not have this problem on Linux, where SVGs render just fine based on the HTML code that Sphinx generates as an intermediary step for SimplePDF.

[dkonigsberg]

Further testing seems to show that this issue has nothing to do with macOS specifically. I can also reproduce it on Linux.

If I run SimplePDF on Sphinx 9.1.0, this SVG sizing issue happens.

If I run SimplePDF on Sphinx 8.2.3, then SVGs are rendered at the correct size