[luatex] Bizarre bug with fontspec, math, and hat/tilde positioning

[Andrew Lutomirski]

On Fri, Aug 5, 2011 at 6:17 PM, Andrew Lutomirski <luto at mit.edu> wrote:
> I'm having trouble with the positioning of hats and tildes in
> lualatex.  To test this, you'll need Linux Libertine OpenType 5.1.3
> unpacked into your current directory.  The issue is that hats and
> tildes (but not both, if the brackets are appropriately positioned)
> are positioned way too far to the left.

It's the *regular* (not italic) font that causes the problem.  Loading
the 05/22/2011 version of LinLibertine_R.otf triggers the problem;
loading 4.75 does not.

>
> xelatex gets this right.  The no-math option to fontspec gets it a lot
> closer to correct.  The older Libertine fonts that come with TexLive
> seem to work as well.
>
> \mathit{\tilde A} has all kinds of different weird issues.
>
> I don't really know if this is the right list for this, since I don't
> know where the bug is.
>
> --- cut here ---
>
> \documentclass[english]{article}
> \usepackage[letterpaper]{geometry}
> \usepackage{babel}
>
> % With no-math, everything works.
> \usepackage{fontspec}
>
> \usepackage{amsmath}
>
> % A new font (5.1.3) in the local directory has issues with LuaTeX.
> \setromanfont[ExternalLocation=./,Mapping=tex-text,UprightFont=*_R,ItalicFont=*_RI,Extension=.otf,Numbers={OldStyle,Proportional}]{LinLibertine}
>
> % An older font that TexLive bundles is OK.
> %\setromanfont[ExternalLocation=/usr/share/texlive/texmf-dist/fonts/opentype/public/libertine/,Mapping=tex-text,UprightFont=*r,ItalicFont=*ri,Extension=.otf,Numbers={OldStyle,Proportional}]{fxl}
>
>
> % But the system version get all but \mathit right.
> %\setromanfont{Linux Libertine O}
>
>
> \begin{document}
>
> \[
> \tilde A
> \]
>
> \[
> {\tilde A}
> \]
>
> \[
> \hat A
> \]
>
> % If amsmath is enabled, then this draws a hat and tilde in the wrong place.
> %\[
> %\hat \tilde A
> %\]
>
> % If amsmath is enabled, then this draws a hat and tilde in the right place (!)
> \[
> \hat{\tilde A}
> \]
>
> \[
> \mathit{\tilde A}
> \]
>
> \end{document}
>