Duplicate clipId in HTML validation

[zepumph]

From phetsims/my-solar-system#88

When I paste an unbuilt version of My Solar System into https://validator.w3.org/nu/#textarea, it tells me that we have a duplicate id for an element:

Looks like that is coming from

scenery/js/display/SVGGroup.js

Line 365 in 7c77d92

const clipId = `clip${this.node.getId()}`;

I wonder if MSS is special in how it applies two different clipAreas to the same node. Should we make that unique? Is this buggy at all? Feel free to unassign.

[jonathanolson]

Not special, it's if there are multiple root SVG elements that need to show the same clip path. It's probably possible to append a unique ID for each SVG block onto all IDs used in such a manner.

It doesn't appear to cause issues so far, so it's unclear to me what priority handling that should be.

[zepumph]

Makes sense! I don't think it is worth the trouble. Unassigning.

[jonathanolson]

Clip areas actually stick with the SVGGroup, and bounce around between different SVG elements as needed. Each clip area now gets its own ID as part of phetsims/faradays-electromagnetic-lab#89, so I think this should be fixed. @zepumph any need to verify?

[zepumph]

Thanks. I don't see that error in the validator now.