Looking for <svg in SVGs might fail

[MagicRB]

The file https://upload.wikimedia.org/wikipedia/commons/4/44/Bridge_pictogram.svg has <svg\n not <svg and so I end up with the following error:

         at /nix/store/kmkz4snxnr6h28ys5y0z2jcjywafip1j-source/topology/renderers/svg/default.nix:52:25:
           51|       then let
           52|         withoutPrefix = head (tail (splitString "<svg " (builtins.readFile file)));
             |                         ^
           53|         content = head (splitString "</svg>" withoutPrefix);

       error: list index 0 is out of bounds

easily fixable but thought I should report.

EDIT: that specific SVG doesn't work anyway, hmm

[oddlama]

Yeah the whole parsing-in-nix is not optimal. I should think of a better way to do all this for v2.0 anyway. For the time being I'd recommend running all svgs through some optimizers, they will ensure the format is compatible:

nix-shell -p nodePackages.svgo scour
scour --enable-viewboxing -i original.svg -o tmp.svg
svgo -i tmp.svg -o final.svg