https://github.com/behdad/harfbuzz/commit/e1d4d0f1dbd8518b5672245c05d73f22a9ed03ea#commitcomment-15006653

AIX fixes

- use '-w' instead of '\<...\>' for check-header-guards
  grep manpage says these are the same

- put '-q' first in the grep options

- move VAR into hb-private.hh

- hb-font-private.hh - use [VAR] instead of [] for variable array

Fixes https://github.com/behdad/harfbuzz/pull/165

Patch from Volker Simonis.

Back in the old days, we used to apply 'calt' and 'cswh' in Arabic shaper,
with a pause in between.  Then we disabled the 'cswh' because Microsoft
disabled it, but forgot to remove the unnecessary pause.  Do that now.

This has the benefit that it fixes shaping with monbaiti from Windows 10.
In that version of that font, the lookups from 'calt' are duplicated in
'rclt', and Mongolian was changed to go through Universal Shaping Engine.
We still use the Arabic shaper for Mongolian.  With a pause after 'calt',
we were applying the duplicate lookups from 'calt' and 'rclt' twice.  It
happened to be the case that these lookups were NOT idempotent.  So we
were getting wrong shaping.  See thread "Windows 10 monbaiti.ttf upgrade
(5.01 -> 5.51) caused loss of diacritical marks when shaped with harfbuz"
on the mailing list.  This fixes that.

[issue 191] Make apply_stch() give a more precise fit

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=93274

Looks like the original sort was wrongly done.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=93275

Currently fails.  Part of
https://bugs.freedesktop.org/show_bug.cgi?id=93275

Add working but less prefect DirectWrite backend

This aims to make Syriac Abbr Mark sizing more accurate when repeating segments are used, by adding an extra repeat and tightening up the spacing slightly rather than leaving a shortfall corresponding to a partial repeat-width.

Fixes https://github.com/behdad/harfbuzz/issues/188
Fixes https://bugs.freedesktop.org/show_bug.cgi?id=93182

This was brorken earlier, though, it's really hard to notice it.
Unlike the glyph_h_origin(), an unset glyph_v_origin() does NOT
mean that the vertical origin is at 0,0.

Related to https://github.com/behdad/harfbuzz/issues/187

Fixes https://github.com/behdad/harfbuzz/issues/187

Funcs implementations that have a non-zero horizontal origin must
implement the glyph_h_origin() callback, nothing new here.

Other implementations (all I know of!) can simply not set
glyph_h_origin() now.  I did that for hb-ot and hb-ft in
44f82750, though that broke the
fallback shaper because the default was returning false...

Fix all VC++ warnings and errors

Enable use of compiler directives to export symbols

Fix y_scale problems in hb-gr

[travis] Enable Mac OS X support

Fixes https://github.com/behdad/harfbuzz/issues/182

I never could get it to work, and it's a proprietary platform.

This prepares the headers for exporting symbols using visibility
attributes or __declspec(dllexport), so that we do not need to maintain
symbols listing files, as this is what was and is done in GLib and GTK+.

Add braces for subobject initializer in _hb_font_funcs_nil

The generic template operator overloading was causing more problems than it
solved.  Eg:

https://github.com/behdad/harfbuzz/pull/163
https://github.com/behdad/harfbuzz/issues/175

So, just use macros.

Fixes https://github.com/behdad/harfbuzz/issues/175
Fixes https://github.com/behdad/harfbuzz/pull/178

To avoid triggering -Wmissing-braces; see https://bugzilla.mozilla.org/show_bug.cgi?id=1226175#c8