[latex3-commits] [git/LaTeX3-latex3-latex2e] develop: fixfor #494 (99f135ec)

[Frank Mittelbach]

Repository : https://github.com/latex3/latex2e
On branch  : develop
Link       : https://github.com/latex3/latex2e/commit/99f135ec5f6a814b4959857143f7889435f8a67c

>---------------------------------------------------------------

commit 99f135ec5f6a814b4959857143f7889435f8a67c
Author: Frank Mittelbach <frank.mittelbach at latex-project.org>
Date:   Mon Feb 8 17:43:01 2021 +0100

    fixfor #494


>---------------------------------------------------------------

99f135ec5f6a814b4959857143f7889435f8a67c
 base/changes.txt  |  6 ++++++
 base/ltmiscen.dtx | 11 ++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/base/changes.txt b/base/changes.txt
index 48f9ebe6..e350435e 100644
--- a/base/changes.txt
+++ b/base/changes.txt
@@ -6,6 +6,12 @@ completeness or accuracy and it contains some references to files that
 are not part of the distribution.
 ================================================================================
 
+2021-02-08  Frank Mittelbach  <Frank.Mittelbach at latex-project.org>
+
+	* ltmiscen.dtx (subsection{Environments}):
+	Undo the internals for \begin and \end as well when
+	rolling back (gh/494)
+
 2021-01-31  David Carlisle  <David.Carlisle at latex-project.org>
 
 	* ltfilehook.dtx: set \protect to \string to avoid bad
diff --git a/base/ltmiscen.dtx b/base/ltmiscen.dtx
index d07b28a7..939bd51a 100644
--- a/base/ltmiscen.dtx
+++ b/base/ltmiscen.dtx
@@ -32,7 +32,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltmiscen.dtx}
-             [2020/12/18 v1.1x LaTeX Kernel (Misc. Environments)]
+             [2021/02/08 v1.1y LaTeX Kernel (Misc. Environments)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltmiscen.dtx}
@@ -868,6 +868,15 @@
 %<latexrelease>  \expandafter\endgroup\if at endpe\@doendpe\fi
 %<latexrelease>  \if at ignore\@ignorefalse\ignorespaces\fi}
 %<latexrelease>
+%    \end{macrocode}
+%    Also undo the internal commands as some packages unfortunately test
+%    for their existence instead of using \cs{IfFormatAtLeastTF}.
+% \changes{v1.1y}{2021/02/08}{Undo the internals for robust \cs{begin}
+%    and \cs{end} in rollback (gh/494)}
+%    \begin{macrocode}
+%<latexrelease>\expandafter\let\csname begin \endcsname\@undefined
+%<latexrelease>\expandafter\let\csname end \endcsname\@undefined
+%<latexrelease>
 %<latexrelease>\EndIncludeInRelease
 %<*2ekernel>
 %    \end{macrocode}