reledmac: in double-spaced document, single-spaced two-col footnotes not aligned

Question

In a double-spaced document with two-column single-spaced footnotes in the reledmac environment (using this solution), the lines across the footnote columns don't line up vertically. This issue disappears if either double-spacing or the \Xbhooknote option is removed, but I'd like to keep both while preserving footnote alignment.

\documentclass[12pt]{article}
\usepackage{reledmac}
\usepackage{lipsum}
\usepackage[]{setspace}
\AtBeginDocument{\doublespacing}
\Xarrangement[A]{twocol}
\Xcolalign{\justifying}
\makeatletter
    \Xbhooknote{\setstretch {\setspace@singlespace}}
\makeatother

\begin{document}
    \beginnumbering
        \pstart
            Ecce \edtext{ipse lorus:}{\Afootnote{i.e. Lorem ipsum.}} \lipsum*[1] \edtext{Haec hactenus.}{\Afootnote{\lipsum*[2]}}
        \pend
    \endnumbering
\end{document}

Answer 1

Quick answer:

• Download the version, 2.7.1, just send on CTAN or on https://github.com/maieul/ledmac/archive/mac2.7.1-par2.6.2.zip
• Use the \Xbhookgroup hook to change also change the line spacing

See this MWE:

\documentclass[12pt]{article}
\usepackage{reledmac}
\usepackage{lipsum}
\usepackage[]{setspace}
\AtBeginDocument{\doublespacing}
\Xarrangement[A]{twocol}
\Xcolalign{\justifying}
\makeatletter
    \Xbhooknote{\setstretch {\setspace@singlespace}}
    \Xbhookgroup{\setstretch {\setspace@singlespace}}
\makeatother

\begin{document}
    \beginnumbering
        \pstart
            Ecce \edtext{ipse lorus:}{\Afootnote{i.e. Lorem ipsum.}} \lipsum*[1] \edtext{Haec hactenus.}{\Afootnote{\lipsum*[2]}}
        \pend
    \endnumbering
\end{document}

Comment

The main problem is that, when splitting in two column the contents of notes, reledmac add vertical space (\splittopskip). This vertical space is calculated on the based of the \baselineskip when outputting the notes, which is not affected by Xbhooknote hook, which concerns only the way footnote are stored in a temporary box. So we also need to set it when outputing the footnotes group, and we use \Xbhookgroup. But it was buged for twocol and threecol footnotes arrangement. It should be solved in 2.7.1