fix for issue/39

required/tools/changes.txt

@@ -5,6 +5,12 @@ completeness or accuracy and it contains some references to files that
 are not part of the distribution.
 =======================================================================
 
+2018-04-20  Frank Mittelbach  <Frank.Mittelbach@latex-project.org>
+
+	* multicol.dtx: restoring column status when leaving a boxed
+	multicols so that any further \docolaction will know the
+	currect column (issue/39)
+
 2018-04-07  Frank Mittelbach  <Frank.Mittelbach@latex-project.org>
 
 	* array.dtx: Renamed internal \mcell@box to

required/tools/multicol.dtx

@@ -98,7 +98,7 @@
 %<driver> \ProvidesFile{multicol.drv}
 % \fi
 %         \ProvidesFile{multicol.dtx}
-          [2018/04/01 v1.8r  multicolumn formatting (FMi)]
+          [2018/04/20 v1.8s  multicolumn formatting (FMi)]
 %
 %
 %%
@@ -1845,9 +1845,15 @@
   \global\c@unbalance\z@
 %    \end{macrocode}
 %    Now it's time to return any footnotes if we are in unrestricted
-%    mode:
+%    mode. In boxed mode footnotes are kept inside, but in that case
+%    we have to write another column status into the \texttt{.aux}
+%    file to support \cs{docolaction} in case we have nested
+%    environments.
+% \changes{v1.8s}{2018/04/20}{Support for \cs{docolaction} (issue/39)}
 %    \begin{macrocode}
-  \if@boxedmulticols\else
+  \if@boxedmulticols
+    \mc@col@status@write
+  \else
     \reinsert@footnotes
 %    \end{macrocode}
 %    We also take a look at the amount of free space on the current

required/tools/testfiles/github-0039.lvt

@@ -0,0 +1,44 @@
+% https://github.com/latex3/latex2e/issues/39
+
+\documentclass[a4paper]{article}
+\usepackage[colaction]{multicol}
+
+\input{test2e}
+
+\makeatletter
+\def\printNumberColumn{%
+\typeout{Status: \the\mc@col@check@num\space = \csname mc@col@type\endcsname}%
+\docolaction{\textbf{col 1}\typeout{col 1}}{}{\textbf{col 2}\typeout{col 2}}
+}
+\makeatother
+
+\setlength\columnseprule{0.4pt}
+
+\def\xxxxx{%
+Test Test Test Test Test Test Test Test
+}
+
+\begin{document}
+
+\START
+
+\begin{multicols}{2}
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\begin{multicols}{2}
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx
+\end{multicols}
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\printNumberColumn\par\xxxxx\xxxxx\xxxxx\xxxxx\xxxxx
+\end{multicols}
+
+\end{document}
+