[XeTeX] sporadic shifted underbrace error

[Khaled Hosny]

The issue is now fixed in git repository.

Regards,
Khaled

On Fri, Feb 08, 2013 at 03:48:51AM +0200, Khaled Hosny wrote:
> Thanks for reproducing the issue. This is clearly an engine bug (unlike
> old TeX, the over/under braces are handled solely by the engine not
> constructed by macros).
> 
> I’ll try to debug this now it is reproducible, but whatever fix I can
> come up with will not be available before the next XeTeX release (TeX
> Live 2013), so It won’t solve your immediate problem, sorry.
> 
> Regards,
> Khaled
> 
> On Wed, Feb 06, 2013 at 12:50:17PM +0800, Daniel Greenhoe wrote:
> > Khaled, thanks for the great suggestion. I used an open type math font
> > (xits-math.otf) and the problem now shows up multiple times. In the
> > attached pdf, the shift occurs on pages 3, 8, 9, 10, 19, 21, 23, 28,
> > 34, ...
> > 
> > My setup includes these:
> > \usepackage[no-config,no-math]{fontspec}  % font selection for xelatex
> > \usepackage{xunicode}                 % unicode character support
> >  \usepackage{amsmath}                 % AMS math package
> >  \usepackage{unicode-math}            % unicode math support
> >  \unimathsetup{math-style=ISO,bold-style=ISO,vargreek-shape=TeX}
> >  \setmathfont{xits-math.otf}
> >  \setmathfont[range={\mathcal,\mathbfcal},StylisticSet=1]{xits-math.otf}
> > 
> > Attached is a tex file and pdf output. Can anyone else reproduce the
> > errors? Any suggestions?
> > 
> >   command line:  xelatex underbrace
> > 
> > Dan
> > 
> > On Wed, Feb 6, 2013 at 11:43 AM, Khaled Hosny <khaledhosny at eglug.org> wrote:
> > > I’ve seen this once with OpenType math fonts, but I wasn’t able to
> > > reproduce it again. Trying using the same fonts in your minimal example,
> > > since it is probably and OpenType math-only issue.
> > >
> > > Regards,
> > > Khaled
> > >
> > > On Wed, Feb 06, 2013 at 11:13:51AM +0800, Daniel Greenhoe wrote:
> > >> I did make a quick minimal example (but not exactly the same as in the
> > >> previous email) that uses the underbrace 1000 (?) times. But so far
> > >> apparently no success in getting the problem to show itself again.
> > >>
> > >> If interested, please see attachments.
> > >>
> > >> Dan
> > >>
> > >>
> > >> On Wed, Feb 6, 2013 at 10:32 AM, Daniel Greenhoe <dgreenhoe at gmail.com> wrote:
> > >> > For some time now I have been having *sporadic* problems with
> > >> > underbraces being shifted to the right by maybe 15mm or so.
> > >> >
> > >> > The problem is sporadic---it appears sometimes, but on the next
> > >> > compile may well have disappeared. The document I am currently working
> > >> > on contains several hundred pages. I can try to put together a minimal
> > >> > example...but that may be of limited use since it may be difficult to
> > >> > get the problem to show itself when I want it to show itself.
> > >> >
> > >> > So, before I do that, might anyone have an idea of what might be the problem?
> > >> >
> > >> > There is a screen capture of a shift. The right underbrace has been
> > >> > shifted far to the right. It should be like the underbrace on the
> > >> > left.
> > >> >
> > >> > Here is my current underbrace macro:
> > >> >
> > >> > \newcommand{\mcom}[3][c]{\ensuremath{%
> > >> >   \begin{array}[t]{#1}%
> > >> >     \underbrace{#2}\\%
> > >> >     \text{\addfontfeatures{Color=mcom}\scriptsize{#3}}%
> > >> >   \end{array}%
> > >> >   }}%
> > >> >
> > >> > The color mcom is simply defined liked this:
> > >> >   \definecolor{mcom}           {cmyk}{0,0,0,1}
> > >> >
> > >> > The \mcom macro can be used something like this:
> > >> >   \[  \mcom{\sin^2(x)+\cos^2(x)=1}{this is a trig. identity} \]
> > >> >
> > >> > I am compiling with XeLaTeX from a TeXlive distribution.
> > >> > Any ideas?
> > >> > Many thanks in advance,
> > >> > Dan
> > >
> > >
> > >
> > >
> > >
> > >>
> > >>
> > >> --------------------------------------------------
> > >> Subscriptions, Archive, and List information, etc.:
> > >>   http://tug.org/mailman/listinfo/xetex
> > >
> > >
> > >
> > > --------------------------------------------------
> > > Subscriptions, Archive, and List information, etc.:
> > >   http://tug.org/mailman/listinfo/xetex
> 
> 
> 
> > 
> > 
> > --------------------------------------------------
> > Subscriptions, Archive, and List information, etc.:
> >   http://tug.org/mailman/listinfo/xetex
>