Inkscape fails to render document with size in "ex" (or "em")

[Radosław Chmielewski]

1. Open the definition of a rectangle from wikipedia : https://en.wikipedia.org/wiki/Rectangle

2. Download any graphic with a mathematical formula, example : https://wikimedia.org/api/rest_v1/media/math/render/svg/f4e29dbea6f5bd06fa2a867edb88e48a535be7d6.

3. Inkscape opens this file as a blank image, claims to be square and very small

rchmielewski@radek-laptop:~/Pulpit$ inkscape --version
Inkscape 0.92.1 unknown

rchmielewski@radek-laptop:~/Pulpit$ inkscape --export-png=png.png wiki.svg
Background RRGGBBAA: ffffff00
Area -1:-1:0:0 exported to 1 x 1 pixels (96 dpi)
Bitmap saved as: png.png

(empty image)

rchmielewski@radek-laptop:~/Pulpit$ inkscape --export-dpi=10000 --export-png=png.png wiki.svg
DPI: 10000
Background RRGGBBAA: ffffff00
Area -1:-1:0:0 exported to 104 x 104 pixels (10000 dpi)
Bitmap saved as: png.png

(empty image)

rchmielewski@radek-laptop:~/Pulpit$ inkscape --query-width wiki.svg
4.4186635e-41
rchmielewski@radek-laptop:~/Pulpit$ inkscape --query-height wiki.svg
9.2745658e-42

[Mc (mc...)]

The problem is caused by the document size being defined in "ex" (relative to the outer font size); so the whole document is like 0x0 for inkscape. Document appears when you change the document unit.

[Radosław Chmielewski (radoslaw.chm)]

I'm using inkscape to render SVGs on the server-side from clients. I do not want to interfere in XMLs to work around the problem. I really need a fix, thank you.