can you expand a little bit about the rationale for this change?

I can't see any reason why the BASE table would be ignored by default. I was subsetting a font with BASE table and with no explanation the BASE table was just dropped. Even with --passthrough-tables it still gets dropped because it's in the _drop_tables_default list. I can understand default dropping some of those other tables, but why BASE?

ok yes, dropping by default may be too blunt.

Even with --passthrough-tables it still gets dropped

hm that's not good, indeed. Can we just fix that?

Ideally the subsetter would trim the BASE script coverage to match the subset. But I have to refresh my memory about BASE table to see how that would work.

Yes, I guess ideally it would trim to match the subset if necessary.

I think here we should simply remove BASE from the _drop_tables_deafault list, so that it respects --no-subset-tables+=BASE or --passthrough-tables, but it is still dropped by default as subsetter does not know how to subset.

Even though it's cumbersome, this should currently work to prevent subsetter to drop BASE table:

--drop-tables-=BASE --no-subset-tables+=BASE

I'm happy to pass it through by default, since that does produce a correct font. @punchcutter can you rebase this plese?

This would be very helpful for some of the projects I'm helping to maintain. I'll take a look at rebasing this next week perhaps

#3949 was merged so this PR can be closed now. Thanks @punchcutter for the original PR, my rebase retained your authorship 🚀