zero width marks test

[phi-gamma]

The test

https://github.com/lualatex/luaotfload/blob/master/tests/zero_width_marks_lig.tex

is rendered incorrectly. This issue is caused upstream. However, if I run the test through Xetex (v 0.9998 from TL2012), I get the same output:

\ifx\directlua\undefined\else\input luaotfload.sty\fi
\font\testa="[TestLig.ttf:script=tibt;+ccmp;+abvs;+blws;+kern]" at 42pt
\testa གཚོའི་ཁིའུ་ཨཱཿཀ
\bye

[phi-gamma]

Hans traced the situation for us. Turns out enabling node mode fixes at least the positioning in the first case:

\font\testa=file:TestLig.ttf:script=tibt;+ccmp;+abvs;+blws;+kern;mode=node;analyze=yes at 42pt

The other issue (two circles overlayed on character) remains.

[eroux]

About XeTeX: it uses Harfbuzz, which has the bug too, see http://lists.freedesktop.org/archives/harfbuzz/2013-April/003101.html

[phi-gamma]

Oh, yeah, I read that. Does forcing node mode help?

[eroux]

It helps yes, now the ligature is ok... but the spacing is too large! and there is still the problem with the two circles... Well, these spacings are weird as they are in the font, but if it's a bug in the font, I would really like to have a solid document based on precise specifications... we'll see... anyway, with the ligature, it half-closes the bug... maybe we could close it when node will be default mode?

[phi-gamma]

maybe we could close it when node will be default mode?

In my repo, we default to node mode already. I’d say if the pull request checks out, then you can close this ticket and open another one for the remaining spacing/circles problem.

[eroux]

Ok, doing that.