* Guard against underflow when adjusting length
With the fuzz-testcase in mozilla bug 1295299, we end up with a recursed lookup that removes 3 items, when `match_positions[idx]` is 0, which results in (unsigned) `end` wrapping to a huge value.
Making `end` a signed int is probably the simplest route to a fix.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1295299.
* Add testcase for #421.
* [indic] Add support for Grantha marks that may be used in Tamil to the Indic table.
See https://bugzilla.mozilla.org/show_bug.cgi?id=1331339.
Testcase: U+0BA4,U+0BC6,U+1133c,U+0BAA,U+1133c,U+0BC6,U+1133c
* [indic] Add test for Grantha nukta that is allowed in Tamil by ScriptExtensions.txt
The numbers for right-to-left scripts are processed also from right to
left, so the order of applying “numr” and “dnom” features should be
reversed in such case.
Fixes https://github.com/behdad/harfbuzz/issues/395
Apparently some clients have reference-table callbacks that copy the table.
As such, avoid loading 'glyf' table which is only needed if fallback positioning
happens.
This is what Microsoft's implementation does. Marks that need advance
need to add it back using 'dist' or other feature in GPOS. Update tests to
match.
Fixes https://github.com/behdad/harfbuzz/issues/211
What happens in that bug is that a mark is attached to base first,
then a second mark is cursive-chained to the first mark. This only
"works" because it's in the Indic shaper where mark advances are
not zeroed.
Before, we didn't allow cursive to run on marks at all. Fix that.
We also where updating mark major offsets at the end of GPOS, such
that changes in advance of base will not change the mark attachment
position. That was superior to the alternative (which is what Uniscribe
does BTW), but made it hard to apply cursive to the mark after it
was positioned. We could track major-direction offset changes and
apply that to cursive in the post process, but that's a much trickier
thing to do than the fix here, which is to immediately apply the
major-direction advance-width offsets... Ie.:
https://github.com/behdad/harfbuzz/issues/211#issuecomment-183194739
If this breaks any fonts, the font should be fixed to do mark attachment
after all the advances are set up first (kerning, etc).
Finally, this, still doesn't make us match Uniscribe, for I explained
in that bug. Looks like Uniscribe applies minor-direction cursive
adjustment immediate as well. We don't, and we like it our way, at
least for now. Eg. the sequence in the test case does this:
- The first subscript attaches with mark-to-base, moving in x only,
- The second subscript attaches with cursive attachment to first subscript
moving in x only,
- A final context rule moves the first subscript up by 104 units.
The way we do, the final shift-up, also shifts up the second subscript
mark because it's cursively-attached. Uniscribe doesn't. We get:
[ttaorya=0+1307|casubscriptorya=0@-242,104+-231|casubscriptnarroworya=0@20,104+507]
while Uniscribe gets:
[ttaorya=0+1307|casubscriptorya=0@-242,104+-211|casubscriptnarroworya=0+487]
note the different y-offset of the last glyph. In our view, after cursive,
things move together, period.
This test font had a upem of 769, which results in rounding-related errors with
the FreeType font funcs. Change the upem to 1024 to fix that.
Fixes https://github.com/behdad/harfbuzz/issues/201
We use three bits for lig_id these days, so we finally got a report of
two separate ligatures with the same lig_id happening adjacent to each
other, and then the component-handling code was breaking things.
Protect against that by ignoring same-lig-id but lig-comp=0 glyphs after
a new ligature.
Fixes https://github.com/behdad/harfbuzz/issues/198
Before, we were just checking the use_category(). This detects as
halant a ligature that had the halant as first glyph (as seen in
NotoSansBalinese.) Change that to use the is_ligated() glyph prop
bit. The font is forming this ligature in ccmp, which is before
the rphf / pref tests. So we need to make sure the "ligated" bit
survives those tests. Since those only check the "substituted" bit,
we now only clear that bit for them and "ligated" survives.
Fixes https://github.com/behdad/harfbuzz/issues/180
This is just to make it harder to be extremely slow. There definitely
are ways still, just harder. Oh well... how do we tame this problem
without solving halting problem?!
Fixes https://github.com/behdad/harfbuzz/issues/174
To fully test what these are supposed to test, they should be run
against libharfbuzz-fuzzing.la instead of libharfbuzz.la, but for
now just record the files.
This resurrects the space fallback feature, after I disabled
the compatibility decomposition. Now I can release HarfBuzz
again without breaking Pango!
It also remembers which space character it was, such that later
on we can approximate the width of this particular space
character. That part is not implemented yet.
We normalize all GC=Zs chars except for U+1680 OGHA SPACE MARK,
which is better left alone.
Fails now. Fix coming. See thread "Issue with cursive attachment"
started by Khaled. Test fonts were made by modifying test font
from Khaled to add more anchors.
In Oriya, a ZWJ/ZWNJ might be added before candrabindu to encourage
or stop ligation of the candrabindu. This is clearly specified in
the Unicode section on Oriya. Allow it there. Note that Uniscribe
doesn't allow this.
Micro tests added using Noto Sans Oriya draft.
No changes in numbers. Currently at:
BENGALI: 353725 out of 354188 tests passed. 463 failed (0.130722%)
DEVANAGARI: 707307 out of 707394 tests passed. 87 failed (0.0122987%)
GUJARATI: 366349 out of 366457 tests passed. 108 failed (0.0294714%)
GURMUKHI: 60732 out of 60747 tests passed. 15 failed (0.0246926%)
KANNADA: 951190 out of 951913 tests passed. 723 failed (0.0759523%)
KHMER: 299070 out of 299124 tests passed. 54 failed (0.0180527%)
MALAYALAM: 1048147 out of 1048334 tests passed. 187 failed (0.0178378%)
ORIYA: 42320 out of 42329 tests passed. 9 failed (0.021262%)
SINHALA: 271662 out of 271847 tests passed. 185 failed (0.068053%)
TAMIL: 1091753 out of 1091754 tests passed. 1 failed (9.15957e-05%)
TELUGU: 970555 out of 970573 tests passed. 18 failed (0.00185457%)
Seems to be what Uniscribe does.
At this point I think it's work checking our default...
Fixes Bug 76767 - Zeroing of advance of 2nd component of multiple
substitution with SBL Hebrew
https://bugs.freedesktop.org/show_bug.cgi?id=76767
Micro-test added.
Looks like Unsicribe responds to the 'mymr' tag by zeroing marks
GDEF_LATE instead of generic-shaper UNICODE_LATE. Implement that.
Fixes
Bug 81775 - Incorrect Rendering with harfbuzz-ng myanmar unicode
https://bugs.freedesktop.org/show_bug.cgi?id=81775
Micro-test added based on Padauk.
Behdad Esfahbod
jfkthame
Khaled Hosny