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adobe-type-tools / afdko

Adobe Font Development Kit for OpenType
https://adobe-type-tools.github.io/afdko/
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[otf2otc] Handling of DSIG tables is suspect #975

Open josh-hadley opened 5 years ago

josh-hadley commented 5 years ago

From the OpenType Specification, Font Collections (TTC/OTC) are supposed to have a single DSIG table for the entire collection file, with its presence indicated and offset & checksum stored in the TTCHeader, which implies that DSIG should not be treated like other shared/unique tables of component fonts.

From observation and inspection of the code, it does not appear that otf2otc performs any special handling of DSIGs per the specification's instructions, and instead treats them like other regular font tables.

madig commented 4 years ago

The interesting question here is if there is any code on this planet that can tell the difference?

josh-hadley commented 4 years ago

"on the planet"? Yes, I wrote it for a validation tool in another life :-) It's not hard to tell.

madig commented 4 years ago

Interesting. The only validator I know of is embedded into the old MS FontVal. Where is your validator used?

josh-hadley commented 4 years ago

You'll have to ask the folks at my other life, I no longer have anything to do with it.