kc3-lang/harfbuzz

2022-10-21T22:33:17

[subset] Always output Lookup's even if they are empty. The rest of layout subsetting depends on lookup indices being consistent with those computed during planning. So if an empty lookup is discarded during the subset phase it will invalidate all subsequent lookup indices. Generally we shouldn't end up with an empty lookup as we pre-prune them during the planning phase, but it can happen in rare cases such as when a subtable is considered degenerate (eg. #3853)