[latex3-commits] [git/LaTeX3-latex3-latex2e] gh479: Do not allocate registers that already exist (04b8a4c8)

[PhelypeOleinik]

Repository : https://github.com/latex3/latex2e
On branch  : gh479
Link       : https://github.com/latex3/latex2e/commit/04b8a4c870bf64f5a003595497d3da999182c733

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

commit 04b8a4c870bf64f5a003595497d3da999182c733
Author: PhelypeOleinik <phelype.oleinik at latex-project.org>
Date:   Thu Mar 18 22:21:36 2021 -0300

    Do not allocate registers that already exist


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

04b8a4c870bf64f5a003595497d3da999182c733
 base/latexrelease.dtx | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/base/latexrelease.dtx b/base/latexrelease.dtx
index c390a360..c67ff9af 100644
--- a/base/latexrelease.dtx
+++ b/base/latexrelease.dtx
@@ -517,6 +517,9 @@ of this package available from CTAN}
   { \@star at or@long \@@_declare_command:Nw }
 \cs_new_protected:Npn \@@_declare_command:Nw #1
   { \cs_if_exist:NTF #1 { \renew at command } { \new at command } #1 }
+\cs_set_protected:Npn \@@_e at alloc:NnnnnN #1 #2 #3 #4 #5 #6
+  { \cs_if_free:NTF #6 { \@@_e at alloc #1 {#2} {#3} {#4} {#5} #6 }
+    { \typeout{Not~defining~\string#1~\string#6} } }
 %    \end{macrocode}
 %
 % Now create a token list to hold the list of changed commands, and
@@ -543,6 +546,12 @@ of this package available from CTAN}
 %     and give an error otherwise (similar to \cs{@ifdefinable}).
 %     Making it a no-op is enough for most cases (except when defining
 %     new registers);
+%   \item[e at alloc] In the case of new registers, we waste an allocation
+%     number if we do \cs[no-index]{new\meta{thing}} in a register
+%     that's already allocated, so the redefinition of \cs{e at alloc}
+%     checks if the new register is really necessary.  This code does
+%     not clear the register, which might cause problems in the future,
+%     if a register is allocated but not properly cleared before using;
 %   \item[__kernel_msg_error:nnx] This command is used to error on
 %     already defined scan marks.  Just making the error do nothing is
 %     enough, as no action is taken in that case;
@@ -560,6 +569,7 @@ of this package available from CTAN}
 %    \begin{macrocode}
 \@@_tmp:w
   \__kernel_chk_if_free_cs:N \use_none:n
+  \e at alloc \@@_e at alloc:NnnnnN
   \__kernel_msg_error:nnx \use_none:nnn
   \__kernel_msg_new:nnn   \__kernel_msg_set:nnn
   \__kernel_msg_new:nnnn  \__kernel_msg_set:nnnn