Checksums (again)

I've been looking into some client-side augmentation ideas recently and I'm reminded of the annoying checksum-related issues.

For example, consider the first note at: https://www.w3.org/TR/WOFF/#DataTables

So: Yes, as things currently stand, if a user-agent manipulates some font tables, it will need to recalculate the checksums to put into the sfnt it generates.

On the other hand, this is a silly thing for a client to be wasting its effort on. If it makes some sort of mistake generating the data the checksum won't catch anything because it's being recalculated afterwards. And don't most browsers sanitize font structure anyway?

At some future meeting I think we should consider asking the CSS folks for an optional extension to the Web Fonts Loading API that is equivalent to "ignore the checksums". Client-side code could then check to see if the option is present and use it in cases when sfnt checksum recalculation is irrelevant.

Skef