Support for pathLength?

[prompteus]

Hi,
resvg ignores pathLength attribute (SVG specification).

<svg height='1000' width='1000' xmlns='http://www.w3.org/2000/svg'>
    <path
        d='M 100 100 L 900 100 L 900 900 L 100 900 Z'
        stroke='black'
        stroke-width='10'
        stroke-dasharray='100 100'
        fill='blue'
        pathLength='1000'
    />
</svg>

Setting pathLength='1000' vs pathLength='10000' should affect the rendered length of the dashes (and gaps) of the stroke. This is specified by SVG 1.1 standard (SVG 2 extends the attribute to rect, circle, etc.)

For reference, I tested the example in a few programs. Here is if they support the pathLength attribute correctly:

✅ Chrome (version 130.0.6723.117 arm64)
✅ Firefox (version 134.0.2, aarch64)
✅ Safari (version 17.4.1)
❌ Inkscape (Inkscape 1.3.2)

[RazrFalcon]

Yes, pathLength isn't supported and for some reason is missing from our unsupported.md docs...