[latex3-commits] [git/LaTeX3-latex3-latex3] main: Revert "Preserve catcode when case changing 8-bit chars < "80" (89a6e9cb4)

[Joseph Wright]

Repository : https://github.com/latex3/latex3
On branch  : main
Link       : https://github.com/latex3/latex3/commit/89a6e9cb4ad2a477608db9a7fdfd032d7734feb6

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

commit 89a6e9cb4ad2a477608db9a7fdfd032d7734feb6
Author: Joseph Wright <joseph.wright at morningstar2.co.uk>
Date:   Wed Nov 9 08:48:18 2022 +0000

    Revert "Preserve catcode when case changing 8-bit chars < "80"
    
    This reverts commit a6aeb66e75ae448d1d2927e9c20a7f5812d21932.


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

89a6e9cb4ad2a477608db9a7fdfd032d7734feb6
 l3kernel/l3text-case.dtx | 44 +++++++++++---------------------------------
 l3kernel/l3unicode.dtx   | 16 ++++++++--------
 2 files changed, 19 insertions(+), 41 deletions(-)

diff --git a/l3kernel/l3text-case.dtx b/l3kernel/l3text-case.dtx
index ff8c2640d..12c18e2f9 100644
--- a/l3kernel/l3text-case.dtx
+++ b/l3kernel/l3text-case.dtx
@@ -704,43 +704,21 @@
   {
     \use:e { \@@_change_case_codepoint_aux:nnnn #1 {#2} }
   }
-%    \end{macrocode}
-%   We need to ensure that only valid catcode-extraction is attempted. That's
-%   fine with Unicode engines but needs a bit of work with 8-bit ones. The
-%   logic is that if the original codepoint was in the ASCII range, we keep
-%   the catcode. Otherwise, if the target is in the ASCII range, we use
-%   the standard catcode. If neither are true, we set as 13 on the grounds that
-%   this will be what is used anyway!
-%    \begin{macrocode}
-\cs_new:Npx \@@_change_case_codepoint_aux:nnnn #1#2#3#4
+\cs_new:Npn \@@_change_case_codepoint_aux:nnnn #1#2#3#4
   {
-    \exp_not:N \@@_codepoint_compare:nNnTF {#4} = {#1}
-      { \exp_not:N \exp_not:n {#4} }
+    \@@_codepoint_compare:nNnTF {#4} = {#1}
+      { \exp_not:n {#4} }
       {
-        \exp_not:N \codepoint_generate:nn {#1}
-          {
-            \bool_lazy_or:nnTF
-              { \sys_if_engine_luatex_p: }
-              { \sys_if_engine_xetex_p: }
-              { \exp_not:N  \@@_char_catcode:N #4 }
-              {
-                \exp_not:N \@@_codepoint_compare:nNnTF {#4} < { "80 }
-                  { \exp_not:N \@@_char_catcode:N #4 }
-                  {
-                    \exp_not:N \int_compare:nNnTF {#1} < { "80 }
-                      { \exp_not:N \char_value_catcode:n {#1} }
-                      { 13 }
-                  }
-              }
-          }
-        \exp_not:N \tl_if_blank:nF {#2}
+        \codepoint_generate:nn {#1}
+          { \@@_char_catcode:N #4 }
+        \tl_if_blank:nF {#2}
           {
-            \exp_not:N \codepoint_generate:nn {#2}
-              { \exp_not:N \char_value_catcode:n {#2} }
-            \exp_not:N \tl_if_blank:nF {#3}
+            \codepoint_generate:nn {#2}
+              { \char_value_catcode:n {#2} }
+            \tl_if_blank:nF {#3}
              {
-               \exp_not:N \codepoint_generate:nn {#3}
-                 { \exp_not:N \char_value_catcode:n {#3} }
+               \codepoint_generate:nn {#3}
+                 { \char_value_catcode:n {#3} }
              }
           }
       }
diff --git a/l3kernel/l3unicode.dtx b/l3kernel/l3unicode.dtx
index 90f6ccaa1..e7466d9a6 100644
--- a/l3kernel/l3unicode.dtx
+++ b/l3kernel/l3unicode.dtx
@@ -55,7 +55,7 @@
 % Unicode \meta{codepoints} and are designed to give useable results with
 % both Unicode-aware and $8$-bit engines.
 %
-% \begin{function}[EXP, added = 2022-10-09, updated = 2022-11-09]
+% \begin{function}[EXP, added = 2022-10-09]
 %   {\codepoint_generate:nn}
 %   \begin{syntax}
 %      \cs{codepoint_generate:nn} \Arg{codepoint} \Arg{catcode}
@@ -80,8 +80,8 @@
 %   produced: these will be the bytes of the UTF-8 representation of the
 %   \meta{codepoint}. For all codepoints outside of the classical ASCII
 %   range, the generated character tokens will be active (category code
-%   $13$); for codepoints in the ASCII range, the given \meta{catcode}
-%   will be used. To allow the result of this function to be used
+%   $13$); for codepoints in the ASCII range, the prevailing category code of
+%   the character is used. To allow the result of this function to be used
 %   inside a expansion context, the result is protected by \cs{exp_not:n}.
 % \end{function}
 %
@@ -191,11 +191,7 @@
         \int_compare:nNnTF {#1} = { `\  }
           { ~ }
           {
-            \int_compare:nNnTF {#1} < { "80 }
-              {
-                \__kernel_exp_not:w \exp_after:wN \exp_after:wN \exp_after:wN
-                  { \char_generate:nn {#1} {#2} }
-              }
+            \int_compare:nNnTF {#1} > { "80 }
               {
                 \use:e
                   {
@@ -203,6 +199,10 @@
                       \__kernel_codepoint_to_bytes:n {#1}
                   }
               }
+              {
+                \__kernel_exp_not:w \exp_after:wN \exp_after:wN \exp_after:wN
+                  { \char_generate:nn {#1} { \char_value_catcode:n {#1} } }
+              }
           }
       }
     \cs_new:Npn \@@_generate:nnnn #1#2#3#4