# [Dev-luatex] bug 345: Kerning is not perfect in math mode

Taco Hoekwater taco at boekplan.nl
Sat Mar 13 12:03:26 CET 2010

Hi,

See http://tracker.luatex.org/view.php?id=345

I've tried to fix this by checking the \catcode of the current
character for 'new math fons' instead of relying on the font's
space() fontdimen like TeX82 does.

This fix is based on the assumption that the 'high numbers' won't
have \catcode 11, so that only the low upright alphabetic characters
will have the italic correction stripped, and those are exactly the
ones we want to reach in 'typical' new math input: this nicely covers
operators that have 'names' like \sin, and any other uses of \rm
in math mode.

The downside is that this fix will break stuff like

$A {\it forces} B$

but I see no way to tackle that automatically.

Best wishes,
Taco