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.
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 2a17f9568d 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
This changes the semantics of get_glyph() callback and expect that
callbacks return false if the requested variant is not available, and
then we will call them back with variation_selector=0 and will retain
the glyph for the selector in the glyph stream.
Apparently most Mongolian fonts implement the Mongolian Variation
Selectors using GSUB, not cmap.
https://bugs.freedesktop.org/show_bug.cgi?id=65258
Note that this doesn't fix the Mongolian shaping yet, because the way
that's implemented is that the, say, 'init' feature ligates the letter
and the variation-selector. However, since currently the variation
selector doesn't have the 'init' mask on, it will not be matched...
Bug 65246 - Fix build without graphite2
If we don't provide ACTION-IF-NOT-FOUND, configure aborts if it can't
find the libraries. We handle that ourselves so we don't want the
macro to abort.
We only want UCDN if we don't have any other Unicode provider.
I'm going to remove ICU from the list of default Unicode providers
as part of moving hb-icu into its own library. As such, the only
providers will be UCDN and glib.
If there's a mark ligating forward with non-mark, they were
inheriting the GC of the mark and later get advance-zeroed.
Don't do that if there's any non-mark glyph in the ligature.
Sample test: U+1780,U+17D2,U+179F with Kh-Metal-Chrieng.ttf
Also:
Bug 58922 - Issue with mark advance zeroing in generic shaper
Behdad Esfahbod
Bradley Grainger
Chun-wei Fan