[HarfBuzz] No kerning?

[Richard Wordingham]

On Tue, 6 Oct 2015 18:52:11 +0100
Jamie Dale <jamiedale88+harfbuzz at gmail.com> wrote:

> 2) What is OT::Sanitizer doing, and could it be skipped without
> leading to crashes?

My understanding is that its job is to prevent crashes and other data
corruption.  A subtable specified by an offset can quite easily be
beyond the bounds of the font, let alone the OT table.  (I assume a
table and its subtables may legitimately interleave with other tables
and their subtables.)

I'm not sure how far things have progressed along the
following line, but it would be helpful to have a tool that reported
what the sanitiser took exception to.  A Uniscribe on Windows 7 had me
baffled when it took exception to substitution with an input of two
glyphs having a subsidiary action for matches applicable to the
substring starting at the third glyph - in the event of a match, the
first glyph would be expanded to two glyphs.  In the other direction,
another OpenType renderer took exception to substitution contexts with
no subsidiary actions for matches.  These contexts were not redundant -
they were bleeding another context.

Richard.