#87 vphantom, superscripts, and unicode-math

[Zhen Lin]

Vertical alignment of superscripts using \vphantom doesn't seem to quite work in unicode-math + XeTeX; see attached file for test case. There is no problem when using XeTeX without unicode-math, and there is no problem when using LuaTeX.

This appears to be a regression: things work as expected in TeX Live 2011 (XeTeX 0.9997.5) but not in TeX Live 2012 (XeTeX 0.9998) or TeX Live 2013 (XeTeX 0.9999.3).

[Anonymous]

I'll give another, even shorter example. The following code goes wrong with XeLaTeX but not with LuaLaTeX: the vertical position of the second 'a' is too low. (If you replace unicode-math by amsmath or remove \usepackage{unicode-math} altogether, everything goes right: both occurrences of 'a' have the same vertical position.)

\documentclass{article}
\usepackage{unicode-math}
\begin{document}
\(|^a\) \(\vphantom{|}^a\)
\end\document}

[U_Fischer]

Work fine for me in texlive 2018 and a current miktex: both a are at the same vertical position.

[Henri Menke]

It's still there in TeX Live 2018, even though it's very subtle.

\documentclass{article}
\usepackage{unicode-math}
\begin{document}

$\vphantom{\textstyle q}_t q_t$%
\llap{\vrule height 0pt depth .1pt width 15pt}

$\vphantom{q}_t q_t$%
\llap{\vrule height 0pt depth .1pt width 15pt}

\end{document}

[Anonymous]

The original file test.tex no more compiles ("greek-shape=unicode" is no more recognized). The bug reported on 2016-02-26 by Anonymous is gone. The bug reported on 2019-01-03 by Henri is still there.

[Henri Menke]

Still broken.

$ xelatex --version
XeTeX 3.14159265-2.6-0.999991 (TeX Live 2019)

[Just A. Man]

I confirm that the original example no longer compiles, and that the bug reported on 2016-02-26 is gone. There is a typo there; the proper source code of the example should have been

\documentclass{article}\pagestyle{empty}
\usepackage{unicode-math}
\begin{document}
\(|^a\) \(\vphantom{|}^a\)
\end{document}

The ouput is attached.

[Just A. Man]

As for the bug reported by Henri, the output is still as he stated using XeTeX 3.14159265-2.6-0.999991 (TeX Live 2019/Debian).

[Just A. Man]

Henri's bug is still there with XeTeX, Version 3.141592653-2.6-0.999994 (TeX Live 2022/Debian) (preloaded format=xelatex 2023.2.17).