--- texlive-20240311-source/texk/web2c/ChangeLog	2024-03-10 22:37:05.000000000 +0100
+++ texlive2024branch/texk/web2c/ChangeLog	2024-03-24 23:30:33.808928698 +0100
@@ -1,3 +1,10 @@
+2024-03-24  Karl Berry  <karl@freefriends.org>
+
+	* unbalanced-braces.ch: fix from DRF in order to make
+	\aftergroup work again with the output routine. Report
+	from David Carlisle and Frank Mittelbach, thread starts at:
+	https://tug.org/pipermail/tex-live/2024-March/050290.html
+
 2024-03-10  Karl Berry  <karl@tug.org>
 
 	* TL'24 release.
--- texlive-20240311-source/texk/web2c/eptexdir/unbalanced-braces-eptex.ch	2024-02-28 05:19:31.000000000 +0100
+++ texlive2024branch/texk/web2c/eptexdir/unbalanced-braces-eptex.ch	2024-03-25 04:14:33.400447000 +0100
@@ -47,7 +47,7 @@
         begin decr(param_ptr);
         flush_list(param_stack[param_ptr]);
         end
-    else if (token_type=output_text)and(output_active) then
+    else if (token_type=output_text)and(not output_can_end) then
       fatal_error("Unbalanced output routine");
 @.Unbalanced output routine@>
 @z
@@ -103,6 +103,19 @@
 % that we were just finished with it, so it's where the brace
 % came from.
 
+@x [45.989] l.19364 p.B417
+@!output_active:boolean; {are we in the midst of an output routine?}
+@y
+@!output_active:boolean; {are we in the midst of an output routine?}
+@!output_can_end:boolean; {is this an auspicious time for it to end?}
+@z
+
+@x [45.989] l.19367 p.B417
+output_active:=false; insert_penalties:=0;
+@y
+output_active:=false; output_can_end:=false; insert_penalties:=0;
+@z
+
 % In <Resume the page builder after an output routine has come to an end>:
 @x [45.1026] l.19938 p.B432
 begin if (loc<>null) or
@@ -121,8 +134,10 @@
 end_token_list; {conserve stack space in case more outputs are triggered}
 end_graf; unsave; output_active:=false; insert_penalties:=0;@/
 @y
-end_graf; unsave; output_active:=false; insert_penalties:=0;@/
+output_can_end:=true;
 end_token_list; {conserve stack space in case more outputs are triggered}
+output_can_end:=false;
+end_graf; unsave; output_active:=false; insert_penalties:=0;@/
 @z
 
 % <Expand macros in the token list and...> had set mode:=0 while
--- texlive-20240311-source/texk/web2c/unbalanced-braces.ch	2024-02-26 16:53:56.000000000 +0100
+++ texlive2024branch/texk/web2c/unbalanced-braces.ch	2024-03-24 23:32:27.599525156 +0100
@@ -1,4 +1,4 @@
-% $Id: unbalanced-braces.ch 70173 2024-02-26 15:53:56Z karl $
+% $Id: unbalanced-braces.ch 70751 2024-03-24 22:32:26Z karl $
 % Fix overrun/underrun of \write and \output. David Fuchs, 2024.
 % Public domain.
 %
@@ -47,7 +47,7 @@
         begin decr(param_ptr);
         flush_list(param_stack[param_ptr]);
         end
-    else if (token_type=output_text)and(output_active) then
+    else if (token_type=output_text)and(not output_can_end) then
       fatal_error("Unbalanced output routine");
 @.Unbalanced output routine@>
 @z
@@ -103,6 +103,19 @@
 % that we were just finished with it, so it's where the brace
 % came from.
 
+@x [45.989] l.19364 p.B417
+@!output_active:boolean; {are we in the midst of an output routine?}
+@y
+@!output_active:boolean; {are we in the midst of an output routine?}
+@!output_can_end:boolean; {is this an auspicious time for it to end?}
+@z
+
+@x [45.989] l.19367 p.B417
+output_active:=false; insert_penalties:=0;
+@y
+output_active:=false; output_can_end:=false; insert_penalties:=0;
+@z
+
 % In <Resume the page builder after an output routine has come to an end>:
 @x [45.1026] l.19938 p.B432
 begin if (loc<>null) or
@@ -121,8 +134,10 @@
 end_token_list; {conserve stack space in case more outputs are triggered}
 end_graf; unsave; output_active:=false; insert_penalties:=0;@/
 @y
-end_graf; unsave; output_active:=false; insert_penalties:=0;@/
+output_can_end:=true;
 end_token_list; {conserve stack space in case more outputs are triggered}
+output_can_end:=false;
+end_graf; unsave; output_active:=false; insert_penalties:=0;@/
 @z
 
 % <Expand macros in the token list and...> had set mode:=0 while