1 files changed, 60 insertions, 32 deletions
diff --git a/Master/texmf-dist/source/latex/base/fontdef.dtx b/Master/texmf-dist/source/latex/base/fontdef.dtx
index 36a31ef19bf..c9c5f5d77dc 100644
--- a/Master/texmf-dist/source/latex/base/fontdef.dtx
+++ b/Master/texmf-dist/source/latex/base/fontdef.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-% Copyright 1993-2018
+% Copyright (C) 1993-2019
 % The LaTeX3 Project and any individual authors listed elsewhere
 % in this file.
 %
@@ -13,7 +13,7 @@
 % The latest version of this license is in
 %    https://www.latex-project.org/lppl.txt
 % and version 1.3c or later is part of all distributions of LaTeX
-% version 2005/12/01 or later.
+% version 2008 or later.
 %
 % This file has the LPPL maintenance status "maintained".
 %
@@ -39,7 +39,7 @@
 %<driver, >\ProvidesFile{fontdef.drv}
 % \fi
 %          \ProvidesFile{fontdef.dtx}
-%<-latexrelease>           [2018/09/24 v3.0b LaTeX Kernel
+%<-latexrelease>           [2019/09/21 v3.0d LaTeX Kernel
 % \iftrue  (\else
 %<text,   >(Text
 %<math,   >(Math
@@ -837,7 +837,6 @@
 %
 %    \begin{macrocode}
 \DeclareMathSymbol{\aleph}{\mathord}{symbols}{"40}
-\def\hbar{{\mathchar'26\mkern-9muh}}
 \DeclareMathSymbol{\imath}{\mathord}{letters}{"7B}
 \DeclareMathSymbol{\jmath}{\mathord}{letters}{"7C}
 \DeclareMathSymbol{\ell}{\mathord}{letters}{"60}
@@ -849,13 +848,8 @@
 \DeclareMathSymbol{\prime}{\mathord}{symbols}{"30}
 \DeclareMathSymbol{\emptyset}{\mathord}{symbols}{"3B}
 \DeclareMathSymbol{\nabla}{\mathord}{symbols}{"72}
-\def\surd{{\mathchar"1270}}
 \DeclareMathSymbol{\top}{\mathord}{symbols}{"3E}
 \DeclareMathSymbol{\bot}{\mathord}{symbols}{"3F}
-\def\angle{{\vbox{\ialign{$\m@th\scriptstyle##$\crcr
-      \not\mathrel{\mkern14mu}\crcr
-      \noalign{\nointerlineskip}
-      \mkern2.5mu\leaders\hrule \@height.34pt\hfill\mkern2.5mu\crcr}}}}
 \DeclareMathSymbol{\triangle}{\mathord}{symbols}{"34}
 \DeclareMathSymbol{\forall}{\mathord}{symbols}{"38}
 \DeclareMathSymbol{\exists}{\mathord}{symbols}{"39}
@@ -869,6 +863,17 @@
 \DeclareMathSymbol{\heartsuit}{\mathord}{symbols}{"7E}
 \DeclareMathSymbol{\spadesuit}{\mathord}{symbols}{"7F}
 %    \end{macrocode}
+%    
+% \changes{v3.0c}{2019/08/27}{Various commands made robust throughout
+%   the file} 
+%    \begin{macrocode}
+\DeclareRobustCommand\hbar{{\mathchar'26\mkern-9muh}}
+\DeclareRobustCommand\surd{{\mathchar"1270}}
+\DeclareRobustCommand\angle{{\vbox{\ialign{$\m@th\scriptstyle##$\crcr
+      \not\mathrel{\mkern14mu}\crcr
+      \noalign{\nointerlineskip}
+      \mkern2.5mu\leaders\hrule \@height.34pt\hfill\mkern2.5mu\crcr}}}}
+%    \end{macrocode}
 %
 %
 % \subsubsection{Large Operators}
@@ -881,14 +886,14 @@
 \DeclareMathSymbol{\bigcap}{\mathop}{largesymbols}{"54}
 \DeclareMathSymbol{\bigcup}{\mathop}{largesymbols}{"53}
 \DeclareMathSymbol{\intop}{\mathop}{largesymbols}{"52}
-    \def\int{\intop\nolimits}
+    \DeclareRobustCommand\int{\intop\nolimits}
 \DeclareMathSymbol{\prod}{\mathop}{largesymbols}{"51}
 \DeclareMathSymbol{\sum}{\mathop}{largesymbols}{"50}
 \DeclareMathSymbol{\bigotimes}{\mathop}{largesymbols}{"4E}
 \DeclareMathSymbol{\bigoplus}{\mathop}{largesymbols}{"4C}
 \DeclareMathSymbol{\bigodot}{\mathop}{largesymbols}{"4A}
 \DeclareMathSymbol{\ointop}{\mathop}{largesymbols}{"48}
-    \def\oint{\ointop\nolimits}
+    \DeclareRobustCommand\oint{\ointop\nolimits}
 \DeclareMathSymbol{\bigsqcup}{\mathop}{largesymbols}{"46}
 \DeclareMathSymbol{\smallint}{\mathop}{symbols}{"73}
 %    \end{macrocode}
@@ -961,7 +966,17 @@
 \DeclareMathSymbol{\Leftrightarrow}{\mathrel}{symbols}{"2C}
 \DeclareMathSymbol{\Leftarrow}{\mathrel}{symbols}{"28}
 \DeclareMathSymbol{\Rightarrow}{\mathrel}{symbols}{"29}
-\def\neq{\not=} \let\ne=\neq
+\DeclareRobustCommand\neq{\not=}
+%    \end{macrocode}
+%    As \cs{neq} is robust we should not use \cs{let} to define
+%    \cs{ne} as then then it would change if \cs{neq} changes.
+% \changes{v3.0d}{2019/09/21}{Distangle alias (gh/184)}
+%    \begin{macrocode}
+%\let\ne=\neq
+\DeclareRobustCommand\ne{\not=}
+%    \end{macrocode}
+%    It is ok to use \cs{let} for those declared by \cs{DeclareMathSymbol}.
+%    \begin{macrocode}
 \DeclareMathSymbol{\leq}{\mathrel}{symbols}{"14}
    \let\le=\leq
 \DeclareMathSymbol{\geq}{\mathrel}{symbols}{"15}
@@ -987,7 +1002,7 @@
 \DeclareMathSymbol{\rightarrow}{\mathrel}{symbols}{"21}
    \let\to=\rightarrow
 \DeclareMathSymbol{\mapstochar}{\mathrel}{symbols}{"37}
-   \def\mapsto{\mapstochar\rightarrow}
+   \DeclareRobustCommand\mapsto{\mapstochar\rightarrow}
 \DeclareMathSymbol{\sim}{\mathrel}{symbols}{"18}
 \DeclareMathSymbol{\simeq}{\mathrel}{symbols}{"27}
 \DeclareMathSymbol{\perp}{\mathrel}{symbols}{"3F}
@@ -1051,9 +1066,9 @@
 \DeclareRobustCommand
   \Relbar{\mathrel{=}}
 \DeclareMathSymbol{\lhook}{\mathrel}{letters}{"2C}
-   \def\hookrightarrow{\lhook\joinrel\rightarrow}
+   \DeclareRobustCommand\hookrightarrow{\lhook\joinrel\rightarrow}
 \DeclareMathSymbol{\rhook}{\mathrel}{letters}{"2D}
-   \def\hookleftarrow{\leftarrow\joinrel\rhook}
+   \DeclareRobustCommand\hookleftarrow{\leftarrow\joinrel\rhook}
 \DeclareRobustCommand
   \bowtie{\mathrel\triangleright\joinrel\mathrel\triangleleft}
 %    \end{macrocode}
@@ -1155,43 +1170,45 @@
 % \subsubsection{Over and under something, etc}
 %
 %    \begin{macrocode}
-\def\overrightarrow#1{\vbox{\m@th\ialign{##\crcr
+\DeclareRobustCommand\overrightarrow[1]{\vbox{\m@th\ialign{##\crcr
       \rightarrowfill\crcr\noalign{\kern-\p@\nointerlineskip}
       $\hfil\displaystyle{#1}\hfil$\crcr}}}
-\def\overleftarrow#1{\vbox{\m@th\ialign{##\crcr
+\DeclareRobustCommand\overleftarrow[1]{\vbox{\m@th\ialign{##\crcr
       \leftarrowfill\crcr\noalign{\kern-\p@\nointerlineskip}%
       $\hfil\displaystyle{#1}\hfil$\crcr}}}
-\def\overbrace#1{\mathop{\vbox{\m@th\ialign{##\crcr\noalign{\kern3\p@}%
+\DeclareRobustCommand\overbrace[1]
+     {\mathop{\vbox{\m@th\ialign{##\crcr\noalign{\kern3\p@}%
       \downbracefill\crcr\noalign{\kern3\p@\nointerlineskip}%
       $\hfil\displaystyle{#1}\hfil$\crcr}}}\limits}
-\def\underbrace#1{\mathop{\vtop{\m@th\ialign{##\crcr
+\DeclareRobustCommand\underbrace[1]{\mathop{\vtop{\m@th\ialign{##\crcr
    $\hfil\displaystyle{#1}\hfil$\crcr
    \noalign{\kern3\p@\nointerlineskip}%
    \upbracefill\crcr\noalign{\kern3\p@}}}}\limits}
 %    \end{macrocode}
 %    (quite a waste of tokens, IMHO --- Frank)
 %    \begin{macrocode}
-\def\skew#1#2#3{{\muskip\z@#1mu\divide\muskip\z@\tw@ \mkern\muskip\z@
+\DeclareRobustCommand\skew[3]
+  {{\muskip\z@#1mu\divide\muskip\z@\tw@ \mkern\muskip\z@
     #2{\mkern-\muskip\z@{#3}\mkern\muskip\z@}\mkern-\muskip\z@}{}}
 %    \end{macrocode}
 %
 % \changes{v2.2n}{1995/11/21}{Incorporate changed figures,
 %                              as in plain.tex}
 %    \begin{macrocode}
-\def\rightarrowfill{$\m@th\smash-\mkern-7mu%
+\DeclareRobustCommand\rightarrowfill{$\m@th\smash-\mkern-7mu%
   \cleaders\hbox{$\mkern-2mu\smash-\mkern-2mu$}\hfill
   \mkern-7mu\mathord\rightarrow$}
-\def\leftarrowfill{$\m@th\mathord\leftarrow\mkern-7mu%
+\DeclareRobustCommand\leftarrowfill{$\m@th\mathord\leftarrow\mkern-7mu%
   \cleaders\hbox{$\mkern-2mu\smash-\mkern-2mu$}\hfill
   \mkern-7mu\smash-$}
 \DeclareMathSymbol{\braceld}{\mathord}{largesymbols}{"7A}
 \DeclareMathSymbol{\bracerd}{\mathord}{largesymbols}{"7B}
 \DeclareMathSymbol{\bracelu}{\mathord}{largesymbols}{"7C}
 \DeclareMathSymbol{\braceru}{\mathord}{largesymbols}{"7D}
-\def\downbracefill{$\m@th \setbox\z@\hbox{$\braceld$}%
+\DeclareRobustCommand\downbracefill{$\m@th \setbox\z@\hbox{$\braceld$}%
   \braceld\leaders\vrule \@height\ht\z@ \@depth\z@\hfill\braceru
   \bracelu\leaders\vrule \@height\ht\z@ \@depth\z@\hfill\bracerd$}
-\def\upbracefill{$\m@th \setbox\z@\hbox{$\braceld$}%
+\DeclareRobustCommand\upbracefill{$\m@th \setbox\z@\hbox{$\braceld$}%
   \bracelu\leaders\vrule \@height\ht\z@ \@depth\z@\hfill\bracerd
   \braceld\leaders\vrule \@height\ht\z@ \@depth\z@\hfill\braceru$}
 %    \end{macrocode}
@@ -1209,7 +1226,18 @@
    {\mathord}{symbols}{"6B}{largesymbols}{"3D}
 \DeclareMathDelimiter{\Vert}
    {\mathord}{symbols}{"6B}{largesymbols}{"0D}
-\let\|=\Vert
+%    \end{macrocode}
+%    \cs{DeclareMathDelimiter} produces a command that is robust (with
+%    an internal macro containing the payload) so we should not use
+%    \cs{let} for making an alias
+% \changes{v3.0d}{2019/09/21}{Distangle alias (gh/184)}
+%    \begin{macrocode}
+%\let\|=\Vert
+\DeclareMathDelimiter{\|}
+   {\mathord}{symbols}{"6B}{largesymbols}{"0D}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
 \DeclareMathDelimiter{\vert}
    {\mathord}{symbols}{"6A}{largesymbols}{"0C}
 \DeclareMathDelimiter{\uparrow}
@@ -1295,8 +1323,8 @@
 %    \end{macrocode}
 %
 %    \begin{macrocode}
-\def\mathsterling{\mathit{\mathchar"7024}}
-\def\mathunderscore{\kern.06em\vbox{\hrule\@width.3em}}
+\DeclareRobustCommand\mathsterling{\mathit{\mathchar"7024}}
+\DeclareRobustCommand\mathunderscore{\kern.06em\vbox{\hrule\@width.3em}}
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -1307,7 +1335,7 @@
 % \begin{macro}{\mathellipsis}
 %    This is plain \TeX's |\ldots|.
 %    \begin{macrocode}
-\def\mathellipsis{\mathinner{\ldotp\ldotp\ldotp}}%
+\DeclareRobustCommand\mathellipsis{\mathinner{\ldotp\ldotp\ldotp}}%
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1321,13 +1349,13 @@
 %<*math|latexrelease>
 %<latexrelease>\IncludeInRelease{2018/12/01}%
 %<latexrelease>                 {\Big}{Start LR-mode}%
-\def\big#1{\leavevmode@ifvmode
+\DeclareRobustCommand\big[1]{\leavevmode@ifvmode
    {\hbox{$\left#1\vbox to8.5\p@{}\right.\n@space$}}}
-\def\Big#1{\leavevmode@ifvmode
+\DeclareRobustCommand\Big[1]{\leavevmode@ifvmode
    {\hbox{$\left#1\vbox to11.5\p@{}\right.\n@space$}}}
-\def\bigg#1{\leavevmode@ifvmode
+\DeclareRobustCommand\bigg[1]{\leavevmode@ifvmode
    {\hbox{$\left#1\vbox to14.5\p@{}\right.\n@space$}}}
-\def\Bigg#1{\leavevmode@ifvmode
+\DeclareRobustCommand\Bigg[1]{\leavevmode@ifvmode
    {\hbox{$\left#1\vbox to17.5\p@{}\right.\n@space$}}}
 %</math|latexrelease>
 %<latexrelease>\EndIncludeInRelease