[latex3-commits] [git/LaTeX3-latex3-latex2e] gh778: Fix result of \@ifdefinable on the empty cs (952afcb8)

[PhelypeOleinik]

Repository : https://github.com/latex3/latex2e
On branch  : gh778
Link       : https://github.com/latex3/latex2e/commit/952afcb8ef70ed3a2d998c643febc8a399525b35

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

commit 952afcb8ef70ed3a2d998c643febc8a399525b35
Author: PhelypeOleinik <phelype.oleinik at latex-project.org>
Date:   Sun Jun 12 23:31:34 2022 -0300

    Fix result of \@ifdefinable on the empty cs
    
    fixes #778


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

952afcb8ef70ed3a2d998c643febc8a399525b35
 base/ltdefns.dtx               | 27 +++++++++++++++++++++++++--
 base/ltexpl.dtx                |  9 ++++++++-
 base/testfiles/github-0778.tlg | 24 +++++++++++++++++++++---
 3 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/base/ltdefns.dtx b/base/ltdefns.dtx
index 9e1fa43f..b5375d84 100644
--- a/base/ltdefns.dtx
+++ b/base/ltdefns.dtx
@@ -32,7 +32,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltdefns.dtx}
-             [2022/05/13 v1.5q LaTeX Kernel (definition commands)]
+             [2022/06/12 v1.5r LaTeX Kernel (definition commands)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltdefns.dtx}
@@ -671,15 +671,20 @@
 % \changes{v1.0n}{1994/05/10}{Removed braces around \cs{@ifundefined}
 %    argument.  ASAJ.}
 % \changes{v1.0s}{1994/05/13}{Coded more efficiently, thanks to FMi.}
+% \changes{v1.5r}{2022/06/12}{Fix result of \cs{@ifdefinable} on the empty cs (gh/778).}
 %
 %  \begin{macro}{\@ifdefinable}
 %  \begin{macro}{\@@ifdefinable}
 %  \begin{macro}{\@rc at ifdefinable}
 %    Test if user is allowed to define a command.
 %    \begin{macrocode}
+%</2ekernel>
+%<*2ekernel|latexrelease>
+%<latexrelease>\IncludeInRelease{2022/11/01}{\@ifdefinable}
+%<latexrelease>                 {Fix \cs{@ifdefinable} on the empty cs}%
 \long\def\@ifdefinable #1#2{%
       \edef\reserved at a{\expandafter\@gobble\string #1}%
-     \@ifundefined\reserved at a
+     \@expl at cs@if at free@@NTF #1%
          {\edef\reserved at b{\expandafter\@carcube \reserved at a xxx\@nil}%
           \ifx \reserved at b\@qend \@notdefinable\else
             \ifx \reserved at a\@qrelax \@notdefinable\else
@@ -687,7 +692,25 @@
             \fi
           \fi}%
          \@notdefinable}
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>
+%<latexrelease>\IncludeInRelease{0000/00/00}{\@ifdefinable}
+%<latexrelease>                 {Fix \cs{@ifdefinable} on the empty cs}%
+%<latexrelease>\long\def\@ifdefinable #1#2{%
+%<latexrelease>      \edef\reserved at a{\expandafter\@gobble\string #1}%
+%<latexrelease>     \@ifundefined\reserved at a
+%<latexrelease>         {\edef\reserved at b{\expandafter\@carcube \reserved at a xxx\@nil}%
+%<latexrelease>          \ifx \reserved at b\@qend \@notdefinable\else
+%<latexrelease>            \ifx \reserved at a\@qrelax \@notdefinable\else
+%<latexrelease>              #2%
+%<latexrelease>            \fi
+%<latexrelease>          \fi}%
+%<latexrelease>         \@notdefinable}
+%<latexrelease>\EndIncludeInRelease
+%</2ekernel|latexrelease>
+%<*2ekernel>
 %    \end{macrocode}
+%
 %    Saved definition of |\@ifdefinable|.
 %    \begin{macrocode}
 \let\@@ifdefinable\@ifdefinable
diff --git a/base/ltexpl.dtx b/base/ltexpl.dtx
index aab189be..06cbc071 100644
--- a/base/ltexpl.dtx
+++ b/base/ltexpl.dtx
@@ -33,7 +33,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltexpl.dtx}
-             [2022/02/28 v1.3f LaTeX Kernel (expl3-dependent code)]
+             [2022/06/12 v1.3g LaTeX Kernel (expl3-dependent code)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltexpl.dtx}
@@ -371,6 +371,12 @@
 \cs_gset_eq:NN \@expl at char@generate@@nn \char_generate:nn
 %    \end{macrocode}
 %
+% \changes{v1.3g}{2022/06/12}
+%         {Add \cs{@expl at cs@if at free@@NTF} for \cs{@ifdefinable} (gh/778)}
+%    \begin{macrocode}
+\cs_gset_eq:NN \@expl at cs@if at free@@NTF \cs_if_free:NTF
+%    \end{macrocode}
+%
 %    \begin{macrocode}
 \ExplSyntaxOff
 %    \end{macrocode}
@@ -390,6 +396,7 @@
 %<latexrelease>\let \@expl at cs@argument at spec@@N \@undefined
 %<latexrelease>\let \@expl at cs@replacement at spec@@N \@undefined
 %<latexrelease>\let \@expl at str@map at function@@NN \@undefined
+%<latexrelease>% \let \@expl at cs@if at free@@NTF \@undefined
 %<latexrelease>\EndIncludeInRelease
 %</2ekernel|latexrelease>
 %    \end{macrocode}
diff --git a/base/testfiles/github-0778.tlg b/base/testfiles/github-0778.tlg
index ffbcf207..8616be3e 100644
--- a/base/testfiles/github-0778.tlg
+++ b/base/testfiles/github-0778.tlg
@@ -11,14 +11,32 @@ If that doesn't work, type  X <return>  to quit.
 ->A.
 <argument> \csname\endcsname
 l. ......ndafter}\expandafter\test\csname\endcsname
-> \csname\endcsname=\long macro:
-->B.
-<argument> \csname\endcsname
+! LaTeX Error: Command \csname\endcsnamealready defined.
+               Or name \end... illegal, see p.192 of the manual.
+See the LaTeX manual or LaTeX Companion for explanation.
+Type  H <return>  for immediate help.
+ ...                                              
 l. ......ndafter}\expandafter\test\csname\endcsname
+Your command was ignored.
+Type  I <command> <return>  to replace it with another command,
+or  <return>  to continue without it.
 > \csname\endcsname=\long macro:
 ->A.
 <argument> \csname\endcsname
 l. ......ndafter}\expandafter\test\csname\endcsname
+! LaTeX Error: Command \csname\endcsnamealready defined.
+               Or name \end... illegal, see p.192 of the manual.
+See the LaTeX manual or LaTeX Companion for explanation.
+Type  H <return>  for immediate help.
+ ...                                              
+l. ......ndafter}\expandafter\test\csname\endcsname
+Your command was ignored.
+Type  I <command> <return>  to replace it with another command,
+or  <return>  to continue without it.
+> \csname\endcsname=macro:
+->\romannumeral \ifx \protect \@typeset at protect \expandafter \expandafter \expandafter \expandafter \expandafter \expandafter \expandafter \z@ \else \expandafter \z@ \expandafter \protect \fi \end  .
+<argument> \csname\endcsname
+l. ......ndafter}\expandafter\test\csname\endcsname
 > \end=\long macro:
 ->B.
 \test ...onment {}{A}{B} \par \show #1 \show \end