Allow data:image in srcset. And the U+002C COMMA character (,) issue

[janmazanek]

What is the issue with the HTML Standard?

According to https://html.spec.whatwg.org/multipage/images.html#srcset-attributes the srcset attribute may not contain ",":
4.8.4.2.1 Srcset attributes > 2: "A valid non-empty URL that does not start or end with a U+002C COMMA character (,)"

How should a "U+002C COMMA character (,)" be escaped/replaced, if it is within an URL? Or in my particular case in data:image?

I wasn't able to escape: "data:image/svg+xml," (,)
with: "data:image/svg+xml%2C" (%2C)
in: srcset="data:image/svg+xml,%3Csvg%20xmlns%3D%27http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%27%20width%3D%27472%27%20height%3D%27314%27%20viewBox%3D%270%200%20472%20314%27%3E%3Crect%20width%3D%27472%27%20height%3D%27314%27%20fill-opacity%3D%220%22%2F%3E%3C%2Fsvg%3E ...."

Notices:
1) I came here from https://github.com/orgs/rehypejs/discussions/78#discussioncomment-1632589, where is described similar issue with URLs without data:image

2) I'm sorry, if this is not a specification issue. In this case, I would kindly ask you, if you could send me a link to a solution (and possibly add it also to https://html.spec.whatwg.org/multipage/images.html#srcset-attributes)

[myakura]

How should a "U+002C COMMA character (,)" be escaped/replaced, if it is within an URL? Or in my particular case in data:image?

does the data URL ever starts with a comma?

[YummyBacon5]

does the data URL ever starts with a comma?

Yes, data:, is the shortest which it can be

[myakura]

Yes, data:, is the shortest which it can be

oh. didn't think data URLs can end with ,. but aren't data URLs are, in most cases, "A valid non-empty URL that does not start or end with a U+002C COMMA character (,)" so can just placed safely in the secret attribute?