Firefox doesn't show the new SVG Favicon:

According to this comment and this link this seems to be due to the used mime type. Doesn't seem to be the mime type, that's already set to image/svg+xml.
Correct mime type is already set, favicon still doesn't show up. Investigating...
Fixed by the above commit. The issue was actually that drawing a SVG to a canvas used internally fails silently in Firefox if the SVG doesn't have width and height attributes. Simply adding those solved the issue immediately.
Pushed and ready for 1.3.10rc2
Thank you!
1.3.10rc2 was just released.
Most helpful comment
Fixed by the above commit. The issue was actually that drawing a SVG to a canvas used internally fails silently in Firefox if the SVG doesn't have width and height attributes. Simply adding those solved the issue immediately.
Pushed and ready for 1.3.10rc2