Empty clip mask should not be removed in SVG export

[iconexperience]

If a Group has an empty path as the clip mask, the other child items are not visible. This is the expected behaviour, because the visible area is zero.

But if the Group is exported as SVG, the empty clip mask will be removed and no clipping will be applied at all in the SVG, so all previously hidden child nodes become visible.

Here is a little example:

var g = new Group();
g.addChild(new Path());
g.addChild(new Path.Circle({center: [100, 100], radius: 50, fillColor: "red"}));
g.clipped = true;

console.log(new XMLSerializer().serializeToString(project.exportSVG()));

And here is the Sketch

If you open the SVG output in a browser, you will see that the red circle is displayed. The SVG output is here:

<svg x="0" y="0" width="1705.00012" height="1530.00012" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <g fill="none" fill-rule="nonzero" stroke="none" stroke-width="1" stroke-linecap="butt" stroke-linejoin="miter" stroke-miterlimit="10" stroke-dasharray="" stroke-dashoffset="0" font-family="none" font-weight="none" font-size="none" text-anchor="none" style="mix-blend-mode: normal">
        <g>
            <path d="M50,100c0,-27.61424 22.38576,-50 50,-50c27.61424,0 50,22.38576 50,50c0,27.61424 -22.38576,50 -50,50c-27.61424,0 -50,-22.38576 -50,-50z" fill="#ff0000"/>
        </g>
    </g>
</svg>

As you can see, the clip mask is gone.

In detail this happens because in SvgExport.js line 72 the function exportSVG() returns null.

To fix this a check if the path is a clip mask could be added in SvgExport.js line 113 like this:

if (segments.length === 0 && !item.isClipMask())