[XeTeX] Problems with thickness of \frac rule and width of accents (\hat) with XeLaTeX

[Khaled Hosny]

On Tue, Aug 17, 2010 at 09:54:00PM +0200, Ulrik Vieth wrote:
[...]
> Unfortunately, there seems to be a major conceptual difference
> between XeTeX and LuaTeX here with respect to font loading of OT
> math fonts, which cannot be resolved quickly without major changes
> to the engine.
> 
> The most feasible short-term solution probably would be to apply a
> XeTeX-specific workaround in the font loading code in unicode-math.

The test file seems to work OK on both engines, if there no major issues
that would result from assigning to families 2 and 3 in luatex, then I
think unicode-math should always do that.

Hmm, thinking a bit more, this is likely to break legacy math control
sequences that has no equivalent in unicode-math yet, which will
currently just grap a glyph from CM, more seriously, it will break
\overbrace and likes since XeTeX support seems not working and
unicode-math is simply using the CM constructs for those.

-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer