Initial setup of gtk-doc. Straight forward setup following the gtk-doc
instructions. Ignore some troublesome types in src/hb-gobject.h. To
build use "./autogen.sh --enable-gtk-doc" then "make". Docs are in
harfbuzz/docs/reference/html/index.html.

See discussion on the list in the thread "Arabic presentation forms
and the uniscribe backend".

Based on patch from Jonathan Kew.

Based on patch from Jonathan Kew and data from Apple.

It's not working correctly though, and I suspect I'm hitting a bug in
CoreText.  When I do this:

hb-shape /Library/Fonts/Zapfino.ttf ZapfinoZapfino --shaper coretext \
--features=-liga

I expect both ligatures to turn off, but only the second one does:

[Z_a_p_f_i_n_o=0+2333|Z=7+395|a=8+285|p_f=9+433|i=11+181|n=12+261|o=13+250]

whereas if I disable 'dlig' instead of 'liga', both are turned off.
Smells...

Doesn't resolve conflicting feature settings.

Rename HB_SCRIPT_CANADIAN_ABORIGINAL to HB_SCRIPT_CANADIAN_SYLLABICS
and a macro for the old name.

Doesn't matter for most users since they should be working in a
fixed sub-pixel scale anyway (ie. 22.10, 26.6, 16.16, etc).

See thread by John Dagget on the list.

Unlike AAT, looks like with CoreText very few OT features can be mapped.
:(

This reverts commit 95212100.

In light of discussion on the mailing list...

As Khaled pointed out, right now setting any features, turns kern
and possibly other features off.

Turning features on globally works now.

As reported by cibu.  Untested.

Windows 8 doesn't, and the spec will be fixed.

Patch from Jonathan Kew.

According to Andrew Glass: "The issue with Myanmar <mark> feature was
fixed via a servicing patch as soon as Windows 8 became available."

When installing per-process fonts using AddFontMemResourceEx(),
if a font with the same family name is already installed, sometimes
that one gets used.  Which is problematic for us.  As such, we
now mangle the font to install a new 'name' table with a unique
name, which we then use to choose the font.

Patch from Jonathan Kew.

During GSUB, if a ligation happens, subsequence context input matching
matches the new indexing.  During GPOS however, the indices never
change.  So just go one by one.

Fixes 'dist' positioning with mmrtext.ttf and the following sequence:

  U+1014,U+1039,U+1011,U+1014,U+1039,U+1011,U+1014,U+1039,U+1011

Reported by Jonathan Kew.

Based on patch from Jonathan Kew, as reported on the mailing list.

Email from Jonathan Kew:

My cygwin build kept aborting on certain test words when run with the
uniscribe backend. Turned out this was caused by a bug in the allocation
of scratch buffers in hb-uniscribe.cc.

Commit 2a17f956 introduced a new line

  ALLOCATE_ARRAY (SCRIPT_VISATTR, vis_attr, glyphs_size);

but it failed to account for this in the computation of glyphs_size
(the number of glyphs for which scratch buffer space is available),
with the result that the vis_clusters array ends up overrunning the
end of the scratch buffer and clobbering the beginning of the buffer's
info[].

AFAICS, the vis_attr array is not actually used, so the simple fix is
to remove the line that allocates it. (If/when we -do- need to use
vis_attr for something, we'll need to add another term to the earlier
calculation of glyphs_size.)

With this patch, the uniscribe backend runs reliably again.

JK

We should add for other scripts too, send me the virama codepoint
and script name...

As per Werner's report on the list.

See email thread "Skipping Control for Attaching Marks using OpenType"
from earlier this month.