1 files changed, 29 insertions, 17 deletions
diff --git a/Master/texmf-dist/source/latex-dev/base/utf8ienc.dtx b/Master/texmf-dist/source/latex-dev/base/utf8ienc.dtx
index a0c96357a03..8789dd35efd 100644
--- a/Master/texmf-dist/source/latex-dev/base/utf8ienc.dtx
+++ b/Master/texmf-dist/source/latex-dev/base/utf8ienc.dtx
@@ -216,7 +216,7 @@
 %<+ts1> \ProvidesFile{ts1enc.dfu}
 %<+x2>  \ProvidesFile{x2enc.dfu}
 %<+all> \ProvidesFile{utf8enc.dfu}
-%<-utf8-2018>   [2021/12/13 v1.2o UTF-8 support]
+%<-utf8-2018>   [2022/02/13 v1.3a UTF-8 support]
 %    \end{macrocode}
 %
 %    \begin{macrocode}
@@ -363,11 +363,12 @@
 % \begin{macro}{\UTFviii@two@octets@noexpand}
 % \begin{macro}{\UTFviii@three@octets@noexpand}
 % \begin{macro}{\UTFviii@four@octets@noexpand}
+% \changes{v1.3a}{2022/02/19}{Use \cs{unexpanded} rather than \cs{noexpand} so only takes one expansion step}%
 %    These temporarily prevent the active chars from expanding.
 %    \begin{macrocode}
-\long\def\UTF@two@octets@noexpand#1#2{\noexpand#2\noexpand}
-\long\def\UTF@three@octets@noexpand#1#2#3{\noexpand#2\noexpand#3\noexpand}
-\long\def\UTF@four@octets@noexpand#1#2#3#4{\noexpand#2\noexpand#3\noexpand#4\noexpand}
+\long\def\UTF@two@octets@noexpand#1#2#3{\unexpanded{#2#3}}
+\long\def\UTF@three@octets@noexpand#1#2#3#4{\unexpanded{#2#3#4}}
+\long\def\UTF@four@octets@noexpand#1#2#3#4#5{\unexpanded{#2#3#4#5}}
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -376,11 +377,12 @@
 % \begin{macro}{\UTFviii@two@octets@string}
 % \begin{macro}{\UTFviii@three@octets@string}
 % \begin{macro}{\UTFviii@four@octets@string}
+% \changes{v1.3a}{2022/02/19}{Use \cs{detokenize} rather than \cs{string} so only takes one expansion step}%
 %    And the same with \cs{string} for use in \cs{csname} constructions.
 %    \begin{macrocode}
-\long\def\UTF@two@octets@string#1#2{\string#2\string}
-\long\def\UTF@three@octets@string#1#2#3{\string#2\string#3\string}
-\long\def\UTF@four@octets@string#1#2#3#4{\string#2\string#3\string#4\string}
+\long\def\UTF@two@octets@string#1#2#3{\detokenize{#2#3}}
+\long\def\UTF@three@octets@string#1#2#3#4{\detokenize{#2#3#4}}
+\long\def\UTF@four@octets@string#1#2#3#4#5{\detokenize{#2#3#4#5}}
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -542,15 +544,24 @@
 %    |\count@| and ending at |\@tempcnta|${} - 1$, each time executing
 %    the code in |\UTFviii@tmp|.
 %
-%    All this is done in a group so that temporary catcode changes
-%    etc.~vanish after everything is set up.
+%    Store current settings so can restore after the loops without using a group (gh/762).
+%
+%    \begin{macrocode}
+\edef\reserved@a{%
+\catcode`\noexpand\~=\the\catcode`\~\relax
+\catcode`\noexpand\"=\the\catcode`\"\relax
+\uccode`\noexpand\~=\the\uccode`\~\relax
+\count@=\the\count@\relax
+\@tempcnta=\the\@tempcnta\relax
+\let\noexpand\reserved@a\relax}
+%    \end{macrocode}
 %
 %    \begin{macrocode}
-\begingroup
 \catcode`\~13
 \catcode`\"12
 %    \end{macrocode}
 %
+% \changes{v1.3a}{2022/02/19}{Use local protected definitions in the character definitions}%
 %    \begin{macrocode}
 \def\UTFviii@loop{%
   \uccode`\~\count@
@@ -566,7 +577,7 @@
 % C0 controls are valid UTF-8 but defined to give the ``Character not defined error''
 % They may be defined with |\DeclareUnicodeCharacter|.
 %    \begin{macrocode}
-    \def\UTFviii@tmp{\xdef~{\noexpand\UTFviii@undefined@err{:\string~}}}
+    \def\UTFviii@tmp{\protected\edef~{\noexpand\UTFviii@undefined@err{:\string~}}}
 % 0 ^^@ null
     \count@"1
     \@tempcnta9
@@ -588,7 +599,7 @@
 %    \begin{macrocode}
     \count@"80
     \@tempcnta"C2
-    \def\UTFviii@tmp{\xdef~{\noexpand\UTFviii@invalid@err\string~}}
+    \def\UTFviii@tmp{\protected\edef~{\noexpand\UTFviii@invalid@err\string~}}
 \UTFviii@loop
 %    \end{macrocode}
 %
@@ -597,7 +608,7 @@
 %    \begin{macrocode}
     \count@"C2
     \@tempcnta"E0
-    \def\UTFviii@tmp{\xdef~{\noexpand\UTFviii@two@octets\noexpand~}}
+    \def\UTFviii@tmp{\protected\edef~{\noexpand\UTFviii@two@octets\noexpand~}}
 \UTFviii@loop
 %    \end{macrocode}
 %
@@ -605,7 +616,7 @@
 %    \begin{macrocode}
     \count@"E0
     \@tempcnta"F0
-    \def\UTFviii@tmp{\xdef~{\noexpand\UTFviii@three@octets\noexpand~}}
+    \def\UTFviii@tmp{\protected\edef~{\noexpand\UTFviii@three@octets\noexpand~}}
 \UTFviii@loop
 %    \end{macrocode}
 %
@@ -614,7 +625,7 @@
 %    \begin{macrocode}
     \count@"F0
     \@tempcnta"F5
-    \def\UTFviii@tmp{\xdef~{\noexpand\UTFviii@four@octets\noexpand~}}
+    \def\UTFviii@tmp{\protected\edef~{\noexpand\UTFviii@four@octets\noexpand~}}
 \UTFviii@loop
 %    \end{macrocode}
 %
@@ -623,12 +634,13 @@
 %    \begin{macrocode}
     \count@"F5
     \@tempcnta"100
-    \def\UTFviii@tmp{\xdef~{\noexpand\UTFviii@invalid@err\string~}}
+    \def\UTFviii@tmp{\protected\edef~{\noexpand\UTFviii@invalid@err\string~}}
 \UTFviii@loop
 %    \end{macrocode}
 %
+% Restore values after the loops.
 %    \begin{macrocode}
-\endgroup
+\reserved@a
 %    \end{macrocode}
 %
 % \end{macro}