To handle forming emoji 'ligatures' in RTL contexts we generate
reversed ligature sequences for the GSUB table. Formerly we only did
this when there was a ZWJ in the sequence, and full reversal worked
because we had no sequences with both fitzpatrick modifiers and ZWJ.
However, now we do. Harfbuzz treats fitzpatrick modifiers as though
they were combining marks and so we need to as well so that GSUB data
is in the order Harfbuzz expects. So we 'unreverse' these pairs.
- Remove PUA character for 'unknown flag' from cmap.
Unfortunately, the contorted build process means we can't do this where
we do our other cmap munging-- font.getGlyphID dies in emoji_builder
if we remove it from the cmap in add_glyphs.py. So we remove it at
the end of emoji_builder.
- Forgot to remap one territory flag, missed it in the spreadsheet. Also
corrected a typo where I remapped the same flag twice. Sorted the flags
in key alpha order.
This adds some additional flags to the default set. In addition,
it contains code that creates ligatures for some flag sequences to
others, for a few cases where we want different regions to share
the same flag. Finally, it adds default ligatures so that pairs of
regional indicator characters for which there's no predefined glyph
get a 'missing flag' glyph. This avoids cases where sequences of
regional indicator sequences accidentally match at odd locations
because of a previous mismatch.
There is no actual 'missing flag' glyph yet. The code uses an
existing emoji as a placeholder.
Doug Felt