Caption Spacing Wrong do to Polyglossia

Question

Consider the following example:

% lualatex test.tex
\DocumentMetadata{}
\documentclass[a4paper]{article}
\usepackage{polyglossia}
\usepackage{graphicx}
\begin{document}
\begin{figure}
 \centering
  \includegraphics[width = 0.99\textwidth]{example-image-a}
 \caption{Test caption.}
\end{figure}
\begin{figure}
 \centering
  \includegraphics[width = \textwidth]{example-image-a}
 \caption{Test caption.}
\end{figure}
\end{document}

As can be seen in the output, the space between the second picture and the corresponding caption is too wide. However, if I remove the polyglossia package, the spacing is correct.

What on Earth is going on and how do I fix it?

Note: I think that this is a somewhat new thing (but I'm not sure); I can't remember ever seeing this before.

Update

A version of the package with a bugfix has now been released; see here.

Not an explanation of the problem, but if you can, I would switch to babel. Babel is much more actively maintained while polyglossia seems to be crumbling to pieces... — samcarter_is_at_topanswers.xyz, Dec 22 '22 at 20:25
@samcarter_is_at_topanswers.xyz Where can I check this statement about Polyglossia? Since Polyglossia's development resumed a few years ago, it seemed to run fine and I haven't run into any problem (within my use case of course). — Miyase, Dec 22 '22 at 20:30
@samcarter_is_at_topanswers.xyz This link is a bit old, and one answer specifies that things have changed since then. Also, the link only points out some lack of features (none of which would impact my usecase anyway), but doesn't say anything about development problems. So I'm still wondering where I could see anything factual indicating that Polyglossia is "crumbling to pieces". — Miyase, Dec 23 '22 at 00:14

David Carlisle · Accepted Answer · 2022-12-22T21:06:50.480

6

If you add \ShowHook{cmd/caption/before} you will see polyglossia has injected code into the start of \caption.

-> The generic hook 'cmd/caption/before':
> Code chunks:
>     polyglossia -> \addtocontents {lof}{\protect \setforeignlanguage {\langua
gename }}\addtocontents {lot}{\protect \setforeignlanguage {\languagename }}

Leaving a blank line before \caption would work around the bug, but it should be reported to polyglossia maintainers.

or patching via the hook:

\documentclass[a4paper]{article}
\AddToHook{cmd/caption/before}[polyglossia]{\par}
\usepackage{polyglossia}
\usepackage{graphicx}
\begin{document}
%\ShowHook{cmd/caption/before}
\begin{figure}
 \centering
  \includegraphics[width = 0.99\textwidth]{example-image-a}
 \caption{Test caption.}
\end{figure}
\begin{figure}
 \centering
  \includegraphics[width = \textwidth]{example-image-a}
 \caption{Test caption.}
\end{figure}
\end{document}

edited Dec 22 '22 at 21:06

answered Dec 22 '22 at 20:54

David Carlisle

757,742

Thank you, David. For some reason I can't log into my Github accout at the moment; can I make you report the "bug"? – Svend Tveskæg Dec 22 '22 at 21:22
1

@SvendTveskæg as it's Christmas:-) – David Carlisle Dec 22 '22 at 21:23
1

@SvendTveskæg https://github.com/reutenauer/polyglossia/issues/575 – David Carlisle Dec 22 '22 at 21:30
I just observed that there is another issue: There is a small white space to the right of the picture, so I have to put a % at the end of the line with \includegraphics in order ot get the correct centering. (This is independant of the width of the picture.) – Svend Tveskæg Dec 23 '22 at 23:41
1

@SvendTveskæg that is exactly the issue, you get space, in the second example a linebreak happens at the space so you get a whole extra line – David Carlisle Dec 23 '22 at 23:45
Ohhh! I see. :-) Thanks for clarifying that for me. – Svend Tveskæg Dec 23 '22 at 23:46
Do you have any idea when the fix will be released? – Svend Tveskæg Dec 25 '22 at 10:48
1

no also it's not entirely unlikely the maintainers are having a break this week @SvendTveskæg – David Carlisle Dec 25 '22 at 13:32

Caption Spacing Wrong do to Polyglossia

1 Answers1