# [luatex] possible engine bug: glyphs displaced

Ulrike Fischer luatex at nililand.de
Thu Mar 2 18:51:41 CET 2017

I'm forwarding a discussion from the luaotfload issue tracker as it
is possible that it indicates a bug introduced between version 1.0.0
and 1.0.4

In the following document the ^^^^0645 is displaced to the left.
With luatex 1.0.0. (miktex) only if it is used in a \hbox.
With luatex 1.0.4. in all three cases.

from the context minimals.

So it looks as if some change in the engine was made -- perhaps to
correct the \hbox error -- which made the problem worse.

Some more details and some pictures can be found here:

Disclaimer: I can't read or write arabic or some other
right-to-left-script.

\documentclass{article}

\begin{document}
\textdir TRT

\font\amiri={file:amiri-regular.ttf:script=arab} at 80pt
\amiri

^^^^0637 ^^^^0645^^^^062d^^^^064a^^^^0637\par

\leavevmode\hbox dir TRT {^^^^0637 ^^^^0645^^^^062d^^^^064a^^^^0637}

\vbox dir TRT {^^^^0637 ^^^^0645^^^^062d^^^^064a^^^^0637}

\end{document}

--
Ulrike Fischer
http://www.troubleshooting-tex.de/