[latex3-commits] [git/LaTeX3-latex3-latex2e] cmd: Do not empty these if they are defined (7913e876)

[PhelypeOleinik]

Repository : https://github.com/latex3/latex2e
On branch  : cmd
Link       : https://github.com/latex3/latex2e/commit/7913e876efa064f556b9ee1ffa85e904cfda2983

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

commit 7913e876efa064f556b9ee1ffa85e904cfda2983
Author: PhelypeOleinik <phelype.oleinik at latex-project.org>
Date:   Sun Jan 24 13:56:09 2021 -0300

    Do not empty these if they are defined
    
    They are required to keep track of the ExplSyntax status after a package ends


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7913e876efa064f556b9ee1ffa85e904cfda2983
 base/ltexpl.dtx | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/base/ltexpl.dtx b/base/ltexpl.dtx
index dab35d12..8ec9291c 100644
--- a/base/ltexpl.dtx
+++ b/base/ltexpl.dtx
@@ -105,10 +105,11 @@
 %<*2ekernel|latexrelease>
 %<latexrelease>\IncludeInRelease{2020/10/01}%
 %<latexrelease>            {\@expl at sys@load at backend@@}{Roll forward support}%
-\def\@expl at sys@load at backend@@{}
-\def\@expl at push@filename@@{}
-\def\@expl at push@filename at aux@@{}
-\def\@expl at pop@filename@@{}
+\def\reserved at a#1{\ifdefined#1\else\def#1{}\fi}
+\reserved at a\@expl at sys@load at backend@@
+\reserved at a\@expl at push@filename@@
+\reserved at a\@expl at push@filename at aux@@
+\reserved at a\@expl at pop@filename@@
 %<latexrelease>\EndIncludeInRelease
 %</2ekernel|latexrelease>
 %    \end{macrocode}