1 files changed, 97 insertions, 13 deletions
diff --git a/macros/latex-dev/base/ltcmd.dtx b/macros/latex-dev/base/ltcmd.dtx
index 78a5a389ae..5f019cdc2a 100644
--- a/macros/latex-dev/base/ltcmd.dtx
+++ b/macros/latex-dev/base/ltcmd.dtx
@@ -1,7 +1,7 @@
 % \iffalse meta-comment
 %
 % Copyright (C) 1999 Frank Mittelbach, Chris Rowley, David Carlisle
-% Copyright (C) 2004-2008 Frank Mittelbach, The LaTeX3 Project
+% Copyright (C) 2004-2008 Frank Mittelbach, The LaTeX Project
 % Copyright (C) 2009-2023
 % The LaTeX Project and any individual authors listed elsewhere
 % in this file.
@@ -34,8 +34,8 @@
 %%% From File: ltcmd.dtx
 %
 %    \begin{macrocode}
-\def\ltcmdversion{v1.1b}
-\def\ltcmddate{2022-11-29}
+\def\ltcmdversion{v1.1d}
+\def\ltcmddate{2023-04-13}
 %    \end{macrocode}
 %
 %<*driver>
@@ -2123,8 +2123,8 @@
 %   and possibly another auxiliary
 %   \cs{\meta{cmd}\textvisiblespace\textvisiblespace}, if the command
 %   has both long and short arguments.  Then, its signature also has
-%   several specific bits that are unique to that command; this is in contrast to
-%   non-expandable commands, which use a common set of parsing functions.
+%   several specific bits that are unique to that command; this is in contrast
+%   to non-expandable commands, which use a common set of parsing functions.
 %
 %   We start by copying the basics, then call
 %   \cs{@@_copy_expandable_signature:NnNNNNnnn} to parse the signature
@@ -2132,7 +2132,24 @@
 %   then we call \cs{@@_copy_expandable:NnNNNNnnn} that will copy the
 %   top-level definition of the command, with the proper internal
 %   renames.
+%
 %    \begin{macrocode}
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_copy:NN}%
+%<latexrelease>  {Support~\NewCommandCopy~in~ltcmd}
+%<latexrelease>\EndIncludeInRelease
+%    \end{macrocode}
+%
+% \changes{v1.1c}{2023/03/12}
+%         {Distinguish (non-expandable) document commands starting with
+%          \cs{@@_start_expandable:nNNNNn}}
+%   There's one variant: a command begins with \cs{@@_start_expandable:nNNNNn}
+%   may still be un-expandable/protected if it's defined by 
+%   \cs{NewDocumentCommand} and friends, with empty or only m-type arguments.
+%
+%    \begin{macrocode}
+%<latexrelease>\IncludeInRelease{2023/06/01}{\@@_copy_expandable:nnNN}%
+%<latexrelease>  {Distinguish~non-expandable~document~commands}
 \cs_new_protected:Npn \@@_copy_expandable:nnNN #1 #2 #3 #4
   {
     \cs_set_eq:cc { #1 ~ code } { #2 ~ code }
@@ -2140,9 +2157,36 @@
     \@@_set_eq_if_exist:cc { #1 ~ \c_space_tl } { #2 ~ \c_space_tl }
     \@@_set_eq_if_exist:cc { #1 ~ defaults } { #2 ~ defaults }
     \exp_after:wN \@@_copy_expandable_signature:NnNNNNnnn #4 {#1} {#2}
-    \cs_set_nopar:Npx #3
+    \token_if_protected_macro:NTF #4
+      { \cs_set_protected_nopar:Npx }{ \cs_set_nopar:Npx }
+      #3
       { \exp_after:wN \@@_copy_expandable:NnNNNNnnn #4 {#1} {#2} }
   }
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{2021/11/15}{\@@_copy_expandable:nnNN}%
+%<latexrelease>  {Support~\NewCommandCopy~in~ltcmd}
+%<latexrelease>\cs_new_protected:Npn \@@_copy_expandable:nnNN #1 #2 #3 #4
+%<latexrelease>  {
+%<latexrelease>    \cs_set_eq:cc { #1 ~ code } { #2 ~ code }
+%<latexrelease>    \@@_set_eq_if_exist:cc { #1 ~ } { #2 ~ }
+%<latexrelease>    \@@_set_eq_if_exist:cc { #1 ~ \c_space_tl } { #2 ~ \c_space_tl }
+%<latexrelease>    \@@_set_eq_if_exist:cc { #1 ~ defaults } { #2 ~ defaults }
+%<latexrelease>    \exp_after:wN \@@_copy_expandable_signature:NnNNNNnnn #4 {#1} {#2}
+%<latexrelease>    \cs_set_nopar:Npx #3
+%<latexrelease>      { \exp_after:wN \@@_copy_expandable:NnNNNNnnn #4 {#1} {#2} }
+%<latexrelease>  }
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_copy_expandable:nnNN}%
+%<latexrelease>  {Support~\NewCommandCopy~in~ltcmd}
+%<latexrelease>\EndIncludeInRelease
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<latexrelease>\IncludeInRelease{2021/11/15}{\@@_copy:NN (part 2)}%
+%<latexrelease>  {Support~\NewCommandCopy~in~ltcmd}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
 \cs_new:Npn \@@_copy_expandable:NnNNNNnnn #1 #2 #3 #4 #5 #6 #7 #8 #9
   {
     \exp_not:N #1 \exp_not:n { {#2} }
@@ -2355,7 +2399,7 @@
 % worth it.
 %    \begin{macrocode}
 %<latexrelease>\EndIncludeInRelease
-%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_copy:NN}%
+%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_copy:NN (part 2)}%
 %<latexrelease>  {Support~\NewCommandCopy~in~ltcmd}
 %<latexrelease>\EndIncludeInRelease
 %    \end{macrocode}
@@ -2418,11 +2462,47 @@
   }
 \cs_new_protected:Npn \@@_show_expandable:N #1
   { \exp_after:wN \@@_show_expandable:NnNNNNnN #1 #1 }
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_show:N}%
+%<latexrelease>  {Support~\ShowCommand~in~ltcmd}
+%<latexrelease>\EndIncludeInRelease
+%    \end{macrocode}
+%
+% \changes{v1.1c}{2023/03/12}
+%         {Distinguish (non-expandable) document commands starting with
+%          \cs{@@_start_expandable:nNNNNn}}
+%   There's one variant: a command begins with \cs{@@_start_expandable:nNNNNn}
+%   may still be un-expandable/protected if it's defined by 
+%   \cs{NewDocumentCommand} and friends, with empty or only m-type arguments.
+%    \begin{macrocode}
+%<latexrelease>\IncludeInRelease{2023/06/01}{\@@_show_expandable:NnNNNNnN}%
+%<latexrelease>  {Distinguish~non-expandable~document~commands}
 \cs_new_protected:Npn \@@_show_expandable:NnNNNNnN #1 #2 #3 #4 #5 #6 #7 #8
   {
-    \@@_show_command_aux:NnNNn \tl_show:x
-      { expandable~document~command } #8 #5 {#2}
+    \exp_args:NNe \@@_show_command_aux:NnNNn \tl_show:x
+      { \token_if_protected_macro:NF #8 { expandable~ } document~command }
+      #8 #5 {#2}
   }
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{2021/11/15}{\@@_show_expandable:NnNNNNnN}%
+%<latexrelease>  {Support~\ShowCommand~in~ltcmd}
+%<latexrelease>\cs_new_protected:Npn \@@_show_expandable:NnNNNNnN #1 #2 #3 #4 #5 #6 #7 #8
+%<latexrelease>  {
+%<latexrelease>    \@@_show_command_aux:NnNNn \tl_show:x
+%<latexrelease>      { expandable~document~command } #8 #5 {#2}
+%<latexrelease>  }
+%<latexrelease>\EndIncludeInRelease
+%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_show_expandable:NnNNNNnN}%
+%<latexrelease>  {Support~\ShowCommand~in~ltcmd}
+%<latexrelease>\EndIncludeInRelease
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<latexrelease>\IncludeInRelease{2021/11/15}{\@@_show:N (part 2)}%
+%<latexrelease>  {Support~\ShowCommand~in~ltcmd}
 %    \end{macrocode}
 %
 %   Now just print everything in the required format.  The auxiliary
@@ -2675,7 +2755,7 @@
 %    \begin{macrocode}
 %<latexrelease>\EndIncludeInRelease
 %
-%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_show:N}%
+%<latexrelease>\IncludeInRelease{2020/10/01}{\@@_show:N (part 2)}%
 %<latexrelease>  {Support~\ShowCommand~in~ltcmd}
 %<latexrelease>\EndIncludeInRelease
 %    \end{macrocode}
@@ -3218,6 +3298,10 @@
 % \begin{macro}{\@@_grab_v_long:w}
 % \begin{macro}{\@@_grab_v_aux:w}
 % \begin{macro}{\@@_grab_v_group_end:}
+%   Firstly, it is necessary to change \cs{tex_endlinechar:D} so that
+%   newlines in different catcode regimes (e.g., \cs{ExplSyntaxOn}) are
+%   not misinterpreted as spaces.
+% \changes{v1.1d}{2023/04/13}{Set \cs{tex_endlinechar:D} earlier (gh/876).}
 %   The opening delimiter is the first non-space token, and is never
 %   read verbatim.  This is required by consistency with the case where
 %   the preceding argument was optional and absent: then \TeX{} has
@@ -3251,6 +3335,7 @@
     \tl_set:Nn \l_@@_signature_tl {#1}
     \group_begin:
       \tex_escapechar:D = 92 \scan_stop:
+      \tex_endlinechar:D = `\^^M \scan_stop:
       \tl_clear:N \l_@@_v_arg_tl
       \peek_remove_spaces:n
         {
@@ -3268,8 +3353,8 @@
   }
 \cs_new_protected:Npn \@@_grab_v_group_end:
   {
-        \exp_args:NNNo
-      \group_end:
+      \exp_args:NNNo
+    \group_end:
     \tl_set:Nn \l_@@_v_arg_tl { \l_@@_v_arg_tl }
   }
 %    \end{macrocode}
@@ -3414,7 +3499,6 @@
   {
     \cs_set_eq:NN \do \char_set_catcode_other:N
     \dospecials
-    \tex_endlinechar:D = `\^^M \scan_stop:
     \bool_if:NTF \l_@@_long_bool
       { \char_set_catcode_other:n { \tex_endlinechar:D } }
       { \char_set_catcode_parameter:n { \tex_endlinechar:D } }