Remove footer separator for empty elements?

[samcarter]

Currently, the foot separator is inserted for each element, regardless whether it is empty or not.

ltx-talk/ltx-talk-frame.dtx

Line 551 in f66735d

\l_@@_footer_sep_tl

For an empty \@institute, this will result in a footer like this:

I'm wondering if there are situations where a double separator is actually desired or if it would make sense to add a test like this?

\tl_if_empty:cF { @ ##1 } { \l__@@_footer_sep_tl }

For "beamer-style" footlines with boxes, one would probably have the footer-element itself in a coloured box, so the separator shouldn't be important for such cases. Are there any other cases to consider?

---

Test file:

% !TeX TS-program = lualatex-dev -interaction=nonstopmode % | txs:///view-pdf | txs:///view-log
\DocumentMetadata{}
\documentclass{ltx-talk}

\title{Title}
\author{Author}
%\institute{}

\EditInstance{footer}{std}{
  separator={\hfill|\hfill},
  element-order={date,author,title,institute,framenumber},
  font=\Huge
}

\begin{document}

\begin{frame}
  abc
\end{frame}

\end{document}