Add missing \changes and changes.txt entries and some docs

base/changes.txt

@@ -10,6 +10,14 @@ are not part of the distribution.
 All changes above are only part of the development branch for the next release.
 ================================================================================
 
+2021-01-07  Phelype Oleinik  <[email protected]>
+
+	* ltfilehook.dtx:
+	Undefine \@expl@@@filehook@file@pop@@ to avoid error when rolling back (gh/463).
+
+	* lthooks.dtx:
+	Modified internal copies of l3tl commands to avoid errors with l3debug (gh/463).
+
 #########################
 # 2020-10-01 PL 3 Release
 #########################

base/ltfilehook.dtx

@@ -31,8 +31,8 @@
 %%% From File: ltfilehook.dtx
 %
 %    \begin{macrocode}
-\providecommand\ltfilehookversion{v1.0d}
-\providecommand\ltfilehookdate{2020/11/24}
+\providecommand\ltfilehookversion{v1.0e}
+\providecommand\ltfilehookdate{2021/01/07}
 %    \end{macrocode}
 %
 %<*driver>
@@ -1491,14 +1491,18 @@
 %
 % This one specifically has to be undefined because it is left over in
 % the input stream from \cs{InputIfFileExists} and executed when
-% \pkg{latexrelease} is loaded.
+% \pkg{latexrelease} is loaded.  It cannot be \cs{let} to \cs{@undefined}
+% otherwise it would error as well, so it is \cs{let} to \cs{relax} to
+% be silently ignored when loading \cs{latexrelease}.
+% \changes{v1.0e}{2021/01/07}{Added rollback for this case to avoid
+%   spurious errors (part of gh/463)}
 %    \begin{macrocode}
 %</2ekernel|latexrelease>
 %<latexrelease>\EndIncludeInRelease
 %<latexrelease>
 %<latexrelease>\IncludeInRelease{0000/00/00}%
 %<latexrelease>    {\@expl@@@filehook@if@no@extension@@nTF}{2e tmp interfaces}%
-%<latexrelease>\let\@expl@@@filehook@file@pop@@\@empty
+%<latexrelease>\let\@expl@@@filehook@file@pop@@\relax
 %<latexrelease>\EndIncludeInRelease
 %<*2ekernel>
 %    \end{macrocode}

base/lthooks.dtx

@@ -32,7 +32,7 @@
 %
 %    \begin{macrocode}
 \def\lthooksversion{v1.0h}
-\def\lthooksdate{2021/01/04}
+\def\lthooksdate{2021/01/07}
 %    \end{macrocode}
 %
 %<*driver>
@@ -1879,6 +1879,13 @@
 %   only add debugging to the public names, not to these copies, so we
 %   don't have to use \cs{debug_suspend:} and \cs{debug_resume:}
 %   everywhere.
+%
+%   Functions like \cs{@@_tl_set:Nn} have to be redefined, rather than
+%   copied because in \pkg{expl3} they use
+%   \cs[no-index]{__kernel_tl_(g)set:Nx}, which is also patched by
+%   \pkg{l3debug}.
+%   \changes{v1.0h}{2021/01/07}{Manually define some \pkg{l3tl} commands
+%     to work around \pkg{expl3} changes}
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_tl_set:Nn #1#2
   { \cs_set_nopar:Npx #1 { \__kernel_exp_not:w {#2} } }