Issue 4969: Update texinfo.tex from upstream

texinfo.tex ver. 2016-09-17.16
It is newer than Texinfo-6.3's.

1 files changed, 487 insertions, 435 deletions

diff --git a/tex/texinfo.tex b/tex/texinfo.tex
index 79bc925655..fad2bc4dc3 100644
--- a/tex/texinfo.tex
+++ b/tex/texinfo.tex
@@ -3,7 +3,7 @@
 % Load plain if necessary, i.e., if running under initex.
 \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
 %
-\def\texinfoversion{2016-07-20.14}
+\def\texinfoversion{2016-09-17.16}
 %
 % Copyright 1985, 1986, 1988, 1990, 1991, 1992, 1993, 1994, 1995,
 % 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
@@ -862,36 +862,6 @@ where each line of input produces a line of output.}
   \temp
 }
 
-% @| inserts a changebar to the left of the current line.  It should
-% surround any changed text.  This approach does *not* work if the
-% change spans more than two lines of output.  To handle that, we would
-% have adopt a much more difficult approach (putting marks into the main
-% vertical list for the beginning and end of each change).  This command
-% is not documented, not supported, and doesn't work.
-%
-\def\|{%
-  % \vadjust can only be used in horizontal mode.
-  \leavevmode
-  %
-  % Append this vertical mode material after the current line in the output.
-  \vadjust{%
-    % We want to insert a rule with the height and depth of the current
-    % leading; that is exactly what \strutbox is supposed to record.
-    \vskip-\baselineskip
-    %
-    % \vadjust-items are inserted at the left edge of the type.  So
-    % the \llap here moves out into the left-hand margin.
-    \llap{%
-      %
-      % For a thicker or thinner bar, change the `1pt'.
-      \vrule height\baselineskip width1pt
-      %
-      % This is the space between the bar and the text.
-      \hskip 12pt
-    }%
-  }%
-}
-
 % @include FILE -- \input text of FILE.
 %
 \def\include{\parseargusing\filenamecatcodes\includezzz}
@@ -1108,9 +1078,14 @@ where each line of input produces a line of output.}
 % For LuaTeX
 %
 
+\newif\iftxiuseunicodedestname
+\txiuseunicodedestnamefalse % For pdfTeX etc.
+
 \ifx\luatexversion\thisisundefined
 \else
-  % Escape PDF strings UTF-8 to UTF-16
+  % Use Unicode destination names
+  \txiuseunicodedestnametrue
+  % Escape PDF strings with converting UTF-16 from UTF-8
   \begingroup
     \catcode`\%=12
     \directlua{
@@ -1138,7 +1113,24 @@ where each line of input produces a line of output.}
       end
     }
   \endgroup
-  \def\pdfescapestring#1{\directlua{UTF16oct('\luaescapestring{#1}')}}
+  \def\pdfescapestrutfsixteen#1{\directlua{UTF16oct('\luaescapestring{#1}')}}
+  % Escape PDF strings without converting
+  \begingroup
+    \directlua{
+      function PDFescstr(str)
+        for c in string.bytes(str) do
+          if c <= 0x20 or c >= 0x80 or c == 0x28 or c == 0x29 or c == 0x5c then
+            tex.sprint(
+              string.format(string.char(0x5c) .. string.char(0x25) .. '03o',
+                            c))
+          else
+            tex.sprint(string.char(c))
+          end
+        end
+      end
+    }
+  \endgroup
+  \def\pdfescapestring#1{\directlua{PDFescstr('\luaescapestring{#1}')}}
   \ifnum\luatexversion>84
     % For LuaTeX >= 0.85
     \def\pdfdest{\pdfextension dest}
@@ -1199,6 +1191,14 @@ where each line of input produces a line of output.}
     \xdef#1{\pdfescapestring{#1}}%
   \fi
 }
+\def\txiescapepdfutfsixteen#1{%
+  \ifx\pdfescapestrutfsixteen\thisisundefined
+    % No UTF-16 converting macro available.
+    \txiescapepdf{#1}%
+  \else
+    \xdef#1{\pdfescapestrutfsixteen{#1}}%
+  \fi
+}
 
 \newhelp\nopdfimagehelp{Texinfo supports .png, .jpg, .jpeg, and .pdf images
 with PDF output, and none of those formats could be found.  (.eps cannot
@@ -1308,19 +1308,77 @@ output) for that.)}
       \pdfrefximage \pdflastximage
     \fi}
   %
-  \def\pdfmkdest#1{{%
+  \def\setpdfdestname#1{{%
     % We have to set dummies so commands such as @code, and characters
     % such as \, aren't expanded when present in a section title.
     \indexnofonts
     \makevalueexpandable
     \turnoffactive
-    % Use ASCII approximations in destination names.
-    \passthroughcharsfalse
+    \iftxiuseunicodedestname
+      \ifx \declaredencoding \latone
+        % Pass through Latin-1 characters.
+        % LuaTeX with byte wise I/O converts Latin-1 characters to Unicode.
+      \else
+        \ifx \declaredencoding \utfeight
+          % Pass through Unicode characters.
+        \else
+          % Use ASCII approximations in destination names.
+          \passthroughcharsfalse
+        \fi
+      \fi
+    \else
+      % Use ASCII approximations in destination names.
+      \passthroughcharsfalse
+    \fi
     \def\pdfdestname{#1}%
     \txiescapepdf\pdfdestname
-    \safewhatsit{\pdfdest name{\pdfdestname} xyz}%
   }}
   %
+  \def\setpdfoutlinetext#1{{%
+    \indexnofonts
+    \makevalueexpandable
+    \turnoffactive
+    \ifx \declaredencoding \latone
+      % The PDF format can use an extended form of Latin-1 in bookmark
+      % strings.  See Appendix D of the PDF Reference, Sixth Edition, for
+      % the "PDFDocEncoding".
+      \passthroughcharstrue
+      % Pass through Latin-1 characters.
+      %   LuaTeX: Convert to Unicode
+      %   pdfTeX: Use Latin-1 as PDFDocEncoding
+      \def\pdfoutlinetext{#1}%
+    \else
+      \ifx \declaredencoding \utfeight
+        \ifx\luatexversion\thisisundefined
+          % For pdfTeX  with UTF-8.
+          % TODO: the PDF format can use UTF-16 in bookmark strings,
+          % but the code for this isn't done yet.
+          % Use ASCII approximations.
+          \passthroughcharsfalse
+          \def\pdfoutlinetext{#1}%
+        \else
+          % For LuaTeX with UTF-8.
+          % Pass through Unicode characters for title texts.
+          \passthroughcharstrue
+          \def\pdfoutlinetext{#1}%
+        \fi
+      \else
+        % For non-Latin-1 or non-UTF-8 encodings.
+        % Use ASCII approximations.
+        \passthroughcharsfalse
+        \def\pdfoutlinetext{#1}%
+      \fi
+    \fi
+    % LuaTeX: Convert to UTF-16
+    % pdfTeX: Use Latin-1 as PDFDocEncoding
+    \txiescapepdfutfsixteen\pdfoutlinetext
+  }}
+  %
+  \def\pdfmkdest#1{%
+    \setpdfdestname{#1}%
+    \safewhatsit{\pdfdest name{\pdfdestname} xyz}%
+  }
+  %
   % used to mark target names; must be expandable.
   \def\pdfmkpgn#1{#1}
   %
@@ -1348,36 +1406,13 @@ output) for that.)}
     % page number.  We could generate a destination for the section
     % text in the case where a section has no node, but it doesn't
     % seem worth the trouble, since most documents are normally structured.
-    {
-      \ifx\luatexversion\thisisundefined \else
-        \turnoffactive % LuaTeX can use Unicode strings for PDF
-      \fi
-      \edef\pdfoutlinedest{#3}%
-      \ifx\pdfoutlinedest\empty
-        \def\pdfoutlinedest{#4}%
-      \else
-        \txiescapepdf\pdfoutlinedest
-      \fi
-      %
-      % Also escape PDF chars in the display string.
-      \bgroup
-        \ifx \declaredencoding \latone
-          % The PDF format can use an extended form of Latin-1 in bookmark
-          % strings.  See Appendix D of the PDF Reference, Sixth Edition, for
-          % the "PDFDocEncoding".
-          \passthroughcharstrue
-        \fi
-        \ifx \declaredencoding \utfeight
-          % TODO: the PDF format can use UTF-16 in bookmark strings, but the
-          % code for this isn't done yet.
-        \fi
-        \globaldefs=1
-        \edef\pdfoutlinetext{#1}%
-        \txiescapepdf\pdfoutlinetext
-      \egroup
-      %
-      \pdfoutline goto name{\pdfmkpgn{\pdfoutlinedest}}#2{\pdfoutlinetext}%
-    }
+    \setpdfoutlinetext{#1}
+    \setpdfdestname{#3}
+    \ifx\pdfdestname\empty
+      \def\pdfdestname{#4}%
+    \fi
+    %
+    \pdfoutline goto name{\pdfmkpgn{\pdfdestname}}#2{\pdfoutlinetext}%
   }
   %
   \def\pdfmakeoutlines{%
@@ -1535,7 +1570,6 @@ output) for that.)}
 %
 % For XeTeX
 %
-\newif\iftxiuseunicodedestname
 \ifx\XeTeXrevision\thisisundefined
 \else
   %
@@ -1543,73 +1577,125 @@ output) for that.)}
   %
   \ifnum\strcmp{\the\XeTeXversion\XeTeXrevision}{0.99996}>-1
     % TeX Live 2016 contains XeTeX 0.99996 and xdvipdfmx 20160307.
-    % It can be used `dvipdfmx:config' special (from TeX Live SVN r40941).
-    % For avoiding PDF destination name replacement, we use the special
-    % instead of xdvipdfmx commandline option `-C 0x0010'.
+    % It can use the `dvipdfmx:config' special (from TeX Live SVN r40941).
+    % For avoiding PDF destination name replacement, we use this special
+    % instead of xdvipdfmx's command line option `-C 0x0010'.
     \special{dvipdfmx:config C 0x0010}
-    % XeTeX 0.99995+ contains xdvipdfmx 20160307+.
-    % It can handle Unicode destination name for PDF.
+    % XeTeX 0.99995+ comes with xdvipdfmx 20160307+.
+    % It can handle Unicode destination names for PDF.
     \txiuseunicodedestnametrue
   \else
-    % XeTeX < 0.99996 (TeX Live < 2016) cannot be used
+    % XeTeX < 0.99996 (TeX Live < 2016) cannot use the
     % `dvipdfmx:config' special.
     % So for avoiding PDF destination name replacement,
-    % xdvipdfmx commandline option `-C 0x0010' is necessary.
+    % xdvipdfmx's command line option `-C 0x0010' is necessary.
     %
-    % XeTeX < 0.99995 can not handle Unicode destination name for PDF
-    % because xdvipdfmx 20150315 has UTF-16 convert issue.
-    % It fixed by xdvipdfmx 20160106 (TeX Live SVN r39753).
+    % XeTeX < 0.99995 can not handle Unicode destination names for PDF
+    % because xdvipdfmx 20150315 has a UTF-16 conversion issue.
+    % It is fixed by xdvipdfmx 20160106 (TeX Live SVN r39753).
     \txiuseunicodedestnamefalse
   \fi
   %
+  % Color support
+  %
+  \def\rgbDarkRed{0.50 0.09 0.12}
+  \def\rgbBlack{0 0 0}
+  %
+  \def\pdfsetcolor#1{\special{pdf:scolor [#1]}}
+  %
+  % Set color, and create a mark which defines \thiscolor accordingly,
+  % so that \makeheadline knows which color to restore.
+  \def\setcolor#1{%
+    \xdef\lastcolordefs{\gdef\noexpand\thiscolor{#1}}%
+    \domark
+    \pdfsetcolor{#1}%
+  }
+  %
+  \def\maincolor{\rgbBlack}
+  \pdfsetcolor{\maincolor}
+  \edef\thiscolor{\maincolor}
+  \def\lastcolordefs{}
+  %
+  \def\makefootline{%
+    \baselineskip24pt
+    \line{\pdfsetcolor{\maincolor}\the\footline}%
+  }
+  %
+  \def\makeheadline{%
+    \vbox to 0pt{%
+      \vskip-22.5pt
+      \line{%
+        \vbox to8.5pt{}%
+        % Extract \thiscolor definition from the marks.
+        \getcolormarks
+        % Typeset the headline with \maincolor, then restore the color.
+        \pdfsetcolor{\maincolor}\the\headline\pdfsetcolor{\thiscolor}%
+      }%
+      \vss
+    }%
+    \nointerlineskip
+  }
+  %
   % PDF outline support
   %
-  % Emulate the primitive of pdfTeX
+  % Emulate pdfTeX primitive
   \def\pdfdest name#1 xyz{%
-    \special{pdf:dest (name#1) [@thispage /XYZ @xpos @ypos null]}%
+    \special{pdf:dest (#1) [@thispage /XYZ @xpos @ypos null]}%
   }
-  \def\pdfmkdest#1{{%
+  %
+  \def\setpdfdestname#1{{%
     % We have to set dummies so commands such as @code, and characters
     % such as \, aren't expanded when present in a section title.
     \indexnofonts
+    \makevalueexpandable
+    \turnoffactive
     \iftxiuseunicodedestname
-      \def\pdfdestname{#1}% Pass through Unicode characters.
+      % Pass through Unicode characters.
     \else
-      \edef\pdfdestname{#1}% Replace Unicode characters to ASCII.
+      % Use ASCII approximations in destination names.
+      \passthroughcharsfalse
     \fi
-    \turnoffactive
-    \makevalueexpandable
+    \def\pdfdestname{#1}%
     \txiescapepdf\pdfdestname
-    \safewhatsit{\pdfdest name{\pdfdestname} xyz}%
   }}
   %
+  \def\setpdfoutlinetext#1{{%
+    \turnoffactive
+    % Always use Unicode characters in title texts.
+    \def\pdfoutlinetext{#1}%
+    % For XeTeX, xdvipdfmx converts to UTF-16.
+    % So we do not convert.
+    \txiescapepdf\pdfoutlinetext
+  }}
+  %
+  \def\pdfmkdest#1{%
+    \setpdfdestname{#1}%
+    \safewhatsit{\pdfdest name{\pdfdestname} xyz}%
+  }
+  %
+  % by default, use black for everything.
+  \def\urlcolor{\rgbBlack}
+  \def\linkcolor{\rgbBlack}
+  \def\endlink{\setcolor{\maincolor}\pdfendlink}
+  %
   \def\dopdfoutline#1#2#3#4{%
-    \iftxiuseunicodedestname
-      \def\pdfoutlinedest{#3}% Pass through Unicode characters.
-    \else
-      \edef\pdfoutlinedest{#3}% Replace Unicode characters to ASCII.
+    \setpdfoutlinetext{#1}
+    \setpdfdestname{#3}
+    \ifx\pdfdestname\empty
+      \def\pdfdestname{#4}%
     \fi
-    \ifx\pdfoutlinedest\empty
-      \def\pdfoutlinedest{#4}%
-    \fi
-    {
-      \turnoffactive
-      \txiescapepdf\pdfoutlinedest
-      \edef\pdfoutlinetext{#1}%
-      \txiescapepdf\pdfoutlinetext
-      %
-      \special{pdf:out [-] #2 << /Title (\pdfoutlinetext) /A
-        << /S /GoTo /D (name\pdfoutlinedest) >> >> }%
-    }
+    %
+    \special{pdf:out [-] #2 << /Title (\pdfoutlinetext) /A
+      << /S /GoTo /D (\pdfdestname) >> >> }%
   }
   %
   \def\pdfmakeoutlines{%
     \begingroup
       %
-      % In the case of XeTeX, counts of subentries is not necesary.
-      % Therefore, read toc only once.
+      % For XeTeX, counts of subentries are not necessary.
+      % Therefore, we read toc only once.
       %
-      % We use the node names as the destinations.
+      % We use node names as destinations.
       \def\partentry##1##2##3##4{}% ignore parts in the outlines
       \def\numchapentry##1##2##3##4{%
         \dopdfoutline{##1}{1}{##3}{##4}}%
@@ -1629,7 +1715,7 @@ output) for that.)}
       \let\unnsubsecentry\numsubsecentry%
       \let\unnsubsubsecentry\numsubsubsecentry%
       %
-      % In the case of XeTeX, xdvipdfmx converts strings to UTF-16.
+      % For XeTeX, xdvipdfmx converts strings to UTF-16.
       % Therefore, the encoding and the language may not be considered.
       %
       \indexnofonts
@@ -1651,9 +1737,9 @@ output) for that.)}
   \special{pdf:docview << /PageMode /UseOutlines >> }
   % ``\special{pdf:tounicode ...}'' is not necessary
   % because xdvipdfmx converts strings from UTF-8 to UTF-16 without it.
-  % However, due to UTF-16 convert issue of xdvipdfmx 20150315,
-  % ``\special{pdf:dest ...}'' can not handle non-ASCII strings.
-  % It fixed by xdvipdfmx 20160106 (TeX Live SVN r39753).
+  % However, due to a UTF-16 conversion issue of xdvipdfmx 20150315,
+  % ``\special{pdf:dest ...}'' cannot handle non-ASCII strings.
+  % It is fixed by xdvipdfmx 20160106 (TeX Live SVN r39753).
 %
   \def\skipspaces#1{\def\PP{#1}\def\D{|}%
     \ifx\PP\D\let\nextsp\relax
@@ -1713,7 +1799,7 @@ output) for that.)}
     {\noexpand\pdflink{\the\toksC}}\toksC={}\global\countA=0}
   \def\pdflink#1{%
     \special{pdf:bann << /Border [0 0 0]
-      /Type /Annot /Subtype /Link /A << /S /GoTo /D (name#1) >> >>}%
+      /Type /Annot /Subtype /Link /A << /S /GoTo /D (#1) >> >>}%
     \setcolor{\linkcolor}#1\endlink}
   \def\done{\edef\st{\global\noexpand\toksA={\the\toksB}}\st}
 %
@@ -1725,7 +1811,7 @@ output) for that.)}
     \def\xeteximagewidth{#2}\setbox0 = \hbox{\ignorespaces #2}%
     \def\xeteximageheight{#3}\setbox2 = \hbox{\ignorespaces #3}%
     %
-    % XeTeX (and the PDF format) support .pdf, .png, .jpg (among
+    % XeTeX (and the PDF format) supports .pdf, .png, .jpg (among
     % others).  Let's try in that order, PDF first since if
     % someone has a scalable image, presumably better to use that than a
     % bitmap.
@@ -1769,40 +1855,9 @@ output) for that.)}
   }
 \fi
 
-\message{fonts,}
-
-% Change the current font style to #1, remembering it in \curfontstyle.
-% For now, we do not accumulate font styles: @b{@i{foo}} prints foo in
-% italics, not bold italics.
-%
-\def\setfontstyle#1{%
-  \def\curfontstyle{#1}% not as a control sequence, because we are \edef'd.
-  \csname ten#1\endcsname  % change the current font
-}
 
-% Select #1 fonts with the current style.
 %
-\def\selectfonts#1{\csname #1fonts\endcsname \csname\curfontstyle\endcsname}
-
-\def\rm{\fam=0 \setfontstyle{rm}}
-\def\it{\fam=\itfam \setfontstyle{it}}
-\def\sl{\fam=\slfam \setfontstyle{sl}}
-\def\bf{\fam=\bffam \setfontstyle{bf}}\def\bfstylename{bf}
-\def\tt{\fam=\ttfam \setfontstyle{tt}}
-
-% Unfortunately, we have to override this for titles and the like, since
-% in those cases "rm" is bold.  Sigh.
-\def\rmisbold{\rm\def\curfontstyle{bf}}
-
-% Texinfo sort of supports the sans serif font style, which plain TeX does not.
-% So we set up a \sf.
-\newfam\sffam
-\def\sf{\fam=\sffam \setfontstyle{sf}}
-\let\li = \sf % Sometimes we call it \li, not \sf.
-
-% We don't need math for this font style.
-\def\ttsl{\setfontstyle{ttsl}}
-
+\message{fonts,}
 
 % Set the baselineskip to #1, and the lineskip and strut size
 % correspondingly.  There is no deep meaning behind these magic numbers
@@ -2153,8 +2208,8 @@ end
 \setfont\deftt\ttshape{10}{\magstep1}{OT1TT}
 \setfont\defsl\slshape{10}{\magstep1}{OT1TT}
 \setfont\defttsl\ttslshape{10}{\magstep1}{OT1TT}
-\def\df{\let\tentt=\deftt \let\tenbf = \defbf
-\let\tenttsl=\defttsl \let\tensl=\defsl \bf}
+\def\df{\let\ttfont=\deftt \let\bffont = \defbf
+\let\ttfontsl=\defttsl \let\slfont=\defsl \bf}
 
 % Fonts for indices, footnotes, small examples (9pt).
 \def\smallnominalsize{9pt}
@@ -2287,8 +2342,8 @@ end
 \setfont\deftt\ttshape{10}{\magstephalf}{OT1TT}
 \setfont\defsl\slshape{10}{\magstephalf}{OT1TT}
 \setfont\defttsl\ttslshape{10}{\magstephalf}{OT1TT}
-\def\df{\let\tentt=\deftt \let\tenbf = \defbf
-\let\tensl=\defsl \let\tenttsl=\defttsl \bf}
+\def\df{\let\ttfont=\deftt \let\bffont = \defbf
+\let\slfont=\defsl \let\ttfontsl=\defttsl \bf}
 
 % Fonts for indices, footnotes, small examples (9pt).
 \def\smallnominalsize{9pt}
@@ -2394,6 +2449,12 @@ end
 \rm
 } % end of 10pt text font size definitions, \definetextfontsizex
 
+% Fonts for short table of contents.
+\setfont\shortcontrm\rmshape{12}{1000}{OT1}
+\setfont\shortcontbf\bfshape{10}{\magstep1}{OT1}  % no cmb12
+\setfont\shortcontsl\slshape{12}{1000}{OT1}
+\setfont\shortconttt\ttshape{12}{1000}{OT1TT}
+
 
 % We provide the user-level command
 %   @fonttextsize 10
@@ -2420,20 +2481,55 @@ end
  \endgroup
 }
 
+%
+% Change the current font style to #1, remembering it in \curfontstyle.
+% For now, we do not accumulate font styles: @b{@i{foo}} prints foo in
+% italics, not bold italics.
+%
+\def\setfontstyle#1{%
+  \def\curfontstyle{#1}% not as a control sequence, because we are \edef'd.
+  \csname #1font\endcsname  % change the current font
+}
+
+\def\rm{\fam=0 \setfontstyle{rm}}
+\def\it{\fam=\itfam \setfontstyle{it}}
+\def\sl{\fam=\slfam \setfontstyle{sl}}
+\def\bf{\fam=\bffam \setfontstyle{bf}}\def\bfstylename{bf}
+\def\tt{\fam=\ttfam \setfontstyle{tt}}
+
+% Unfortunately, we have to override this for titles and the like, since
+% in those cases "rm" is bold.  Sigh.
+\def\rmisbold{\rm\def\curfontstyle{bf}}
+
+% Texinfo sort of supports the sans serif font style, which plain TeX does not.
+% So we set up a \sf.
+\newfam\sffam
+\def\sf{\fam=\sffam \setfontstyle{sf}}
+
+% We don't need math for this font style.
+\def\ttsl{\setfontstyle{ttsl}}
+
+
 % In order for the font changes to affect most math symbols and letters,
 % we have to define the \textfont of the standard families.  We don't
 % bother to reset \scriptfont and \scriptscriptfont; awaiting user need.
 %
 \def\resetmathfonts{%
-  \textfont0=\tenrm \textfont1=\teni \textfont2=\tensy
-  \textfont\itfam=\tenit \textfont\slfam=\tensl \textfont\bffam=\tenbf
-  \textfont\ttfam=\tentt \textfont\sffam=\tensf
+  \textfont0=\rmfont \textfont1=\ifont \textfont2=\syfont
+  \textfont\itfam=\itfont \textfont\slfam=\slfont \textfont\bffam=\bffont
+  \textfont\ttfam=\ttfont \textfont\sffam=\sffont
 }
 
-% The font-changing commands redefine the meanings of \tenSTYLE, instead
+% Select #1 fonts with the current style.  Used to change font size
+% in, e.g., the LaTeX logo and acronyms.
+%
+\def\selectfonts#1{\csname #1fonts\endcsname \csname\curfontstyle\endcsname}
+
+% The font-changing commands (all called \...fonts) redefine the meanings of 
+% \STYLEfont, instead
 % of just \STYLE.  We do this because \STYLE needs to also set the
 % current \fam for math mode.  Our \STYLE (e.g., \rm) commands hardwire
-% \tenSTYLE to set the current font.
+% \STYLEfont to set the current font.
 %
 % Each font-changing command also sets the names \lsize (one size lower)
 % and \lllsize (three sizes lower).  These relative commands are used
@@ -2442,78 +2538,72 @@ end
 % This all needs generalizing, badly.
 %
 \def\textfonts{%
-  \let\tenrm=\textrm \let\tenit=\textit \let\tensl=\textsl
-  \let\tenbf=\textbf \let\tentt=\texttt \let\smallcaps=\textsc
-  \let\tensf=\textsf \let\teni=\texti \let\tensy=\textsy
-  \let\tenttsl=\textttsl
+  \let\rmfont=\textrm \let\itfont=\textit \let\slfont=\textsl
+  \let\bffont=\textbf \let\ttfont=\texttt \let\smallcaps=\textsc
+  \let\sffont=\textsf \let\ifont=\texti \let\syfont=\textsy
+  \let\ttfontsl=\textttsl
   \def\curfontsize{text}%
   \def\lsize{reduced}\def\lllsize{smaller}%
   \resetmathfonts \setleading{\textleading}}
 \def\titlefonts{%
-  \let\tenrm=\titlerm \let\tenit=\titleit \let\tensl=\titlesl
-  \let\tenbf=\titlebf \let\tentt=\titlett \let\smallcaps=\titlesc
-  \let\tensf=\titlesf \let\teni=\titlei \let\tensy=\titlesy
-  \let\tenttsl=\titlettsl
+  \let\rmfont=\titlerm \let\itfont=\titleit \let\slfont=\titlesl
+  \let\bffont=\titlebf \let\ttfont=\titlett \let\smallcaps=\titlesc
+  \let\sffont=\titlesf \let\ifont=\titlei \let\syfont=\titlesy
+  \let\ttfontsl=\titlettsl
   \def\curfontsize{title}%
   \def\lsize{chap}\def\lllsize{subsec}%
   \resetmathfonts \setleading{27pt}}
 \def\titlefont#1{{\titlefonts\rmisbold #1}}
 \def\chapfonts{%
-  \let\tenrm=\chaprm \let\tenit=\chapit \let\tensl=\chapsl
-  \let\tenbf=\chapbf \let\tentt=\chaptt \let\smallcaps=\chapsc
-  \let\tensf=\chapsf \let\teni=\chapi \let\tensy=\chapsy
-  \let\tenttsl=\chapttsl
+  \let\rmfont=\chaprm \let\itfont=\chapit \let\slfont=\chapsl
+  \let\bffont=\chapbf \let\ttfont=\chaptt \let\smallcaps=\chapsc
+  \let\sffont=\chapsf \let\ifont=\chapi \let\syfont=\chapsy
+  \let\ttfontsl=\chapttsl
   \def\curfontsize{chap}%
   \def\lsize{sec}\def\lllsize{text}%
   \resetmathfonts \setleading{19pt}}
 \def\secfonts{%
-  \let\tenrm=\secrm \let\tenit=\secit \let\tensl=\secsl
-  \let\tenbf=\secbf \let\tentt=\sectt \let\smallcaps=\secsc
-  \let\tensf=\secsf \let\teni=\seci \let\tensy=\secsy
-  \let\tenttsl=\secttsl
+  \let\rmfont=\secrm \let\itfont=\secit \let\slfont=\secsl
+  \let\bffont=\secbf \let\ttfont=\sectt \let\smallcaps=\secsc
+  \let\sffont=\secsf \let\ifont=\seci \let\syfont=\secsy
+  \let\ttfontsl=\secttsl
   \def\curfontsize{sec}%
   \def\lsize{subsec}\def\lllsize{reduced}%
   \resetmathfonts \setleading{17pt}}
 \def\subsecfonts{%
-  \let\tenrm=\ssecrm \let\tenit=\ssecit \let\tensl=\ssecsl
-  \let\tenbf=\ssecbf \let\tentt=\ssectt \let\smallcaps=\ssecsc
-  \let\tensf=\ssecsf \let\teni=\sseci \let\tensy=\ssecsy
-  \let\tenttsl=\ssecttsl
+  \let\rmfont=\ssecrm \let\itfont=\ssecit \let\slfont=\ssecsl
+  \let\bffont=\ssecbf \let\ttfont=\ssectt \let\smallcaps=\ssecsc
+  \let\sffont=\ssecsf \let\ifont=\sseci \let\syfont=\ssecsy
+  \let\ttfontsl=\ssecttsl
   \def\curfontsize{ssec}%
   \def\lsize{text}\def\lllsize{small}%
   \resetmathfonts \setleading{15pt}}
 \let\subsubsecfonts = \subsecfonts
 \def\reducedfonts{%
-  \let\tenrm=\reducedrm \let\tenit=\reducedit \let\tensl=\reducedsl
-  \let\tenbf=\reducedbf \let\tentt=\reducedtt \let\reducedcaps=\reducedsc
-  \let\tensf=\reducedsf \let\teni=\reducedi \let\tensy=\reducedsy
-  \let\tenttsl=\reducedttsl
+  \let\rmfont=\reducedrm \let\itfont=\reducedit \let\slfont=\reducedsl
+  \let\bffont=\reducedbf \let\ttfont=\reducedtt \let\reducedcaps=\reducedsc
+  \let\sffont=\reducedsf \let\ifont=\reducedi \let\syfont=\reducedsy
+  \let\ttfontsl=\reducedttsl
   \def\curfontsize{reduced}%
   \def\lsize{small}\def\lllsize{smaller}%
   \resetmathfonts \setleading{10.5pt}}
 \def\smallfonts{%
-  \let\tenrm=\smallrm \let\tenit=\smallit \let\tensl=\smallsl
-  \let\tenbf=\smallbf \let\tentt=\smalltt \let\smallcaps=\smallsc
-  \let\tensf=\smallsf \let\teni=\smalli \let\tensy=\smallsy
-  \let\tenttsl=\smallttsl
+  \let\rmfont=\smallrm \let\itfont=\smallit \let\slfont=\smallsl
+  \let\bffont=\smallbf \let\ttfont=\smalltt \let\smallcaps=\smallsc
+  \let\sffont=\smallsf \let\ifont=\smalli \let\syfont=\smallsy
+  \let\ttfontsl=\smallttsl
   \def\curfontsize{small}%
   \def\lsize{smaller}\def\lllsize{smaller}%
   \resetmathfonts \setleading{10.5pt}}
 \def\smallerfonts{%
-  \let\tenrm=\smallerrm \let\tenit=\smallerit \let\tensl=\smallersl
-  \let\tenbf=\smallerbf \let\tentt=\smallertt \let\smallcaps=\smallersc
-  \let\tensf=\smallersf \let\teni=\smalleri \let\tensy=\smallersy
-  \let\tenttsl=\smallerttsl
+  \let\rmfont=\smallerrm \let\itfont=\smallerit \let\slfont=\smallersl
+  \let\bffont=\smallerbf \let\ttfont=\smallertt \let\smallcaps=\smallersc
+  \let\sffont=\smallersf \let\ifont=\smalleri \let\syfont=\smallersy
+  \let\ttfontsl=\smallerttsl
   \def\curfontsize{smaller}%
   \def\lsize{smaller}\def\lllsize{smaller}%
   \resetmathfonts \setleading{9.5pt}}
 
-% Fonts for short table of contents.
-\setfont\shortcontrm\rmshape{12}{1000}{OT1}
-\setfont\shortcontbf\bfshape{10}{\magstep1}{OT1}  % no cmb12
-\setfont\shortcontsl\slshape{12}{1000}{OT1}
-\setfont\shortconttt\ttshape{12}{1000}{OT1TT}
-
 % Define these just so they can be easily changed for other fonts.
 \def\angleleft{$\langle$}
 \def\angleright{$\rangle$}
@@ -3297,23 +3387,10 @@ end
 \let\atchar=\@
 
 % @{ @} @lbracechar{} @rbracechar{} all generate brace characters.
-% Unless we're in typewriter, use \ecfont because the CM text fonts do
-% not have braces, and we don't want to switch into math.
-\def\mylbrace{{\ifmonospace\char123\else\ensuremath\lbrace\fi}}
-\def\myrbrace{{\ifmonospace\char125\else\ensuremath\rbrace\fi}}
-\let\{=\mylbrace \let\lbracechar=\{
-\let\}=\myrbrace \let\rbracechar=\}
-\begingroup
-  % Definitions to produce \{ and \} commands for indices,
-  % and @{ and @} for the aux/toc files.
-  \catcode`\{ = \other \catcode`\} = \other
-  \catcode`\[ = 1 \catcode`\] = 2
-  \catcode`\! = 0 \catcode`\\ = \other
-  !gdef!lbracecmd[\{]%
-  !gdef!rbracecmd[\}]%
-  !gdef!lbraceatcmd[@{]%
-  !gdef!rbraceatcmd[@}]%
-!endgroup
+\def\lbracechar{{\ifmonospace\char123\else\ensuremath\lbrace\fi}}
+\def\rbracechar{{\ifmonospace\char125\else\ensuremath\rbrace\fi}}
+\let\{=\lbracechar
+\let\}=\rbracechar
 
 % @comma{} to avoid , parsing problems.
 \let\comma = ,
@@ -3432,7 +3509,7 @@ end
 %
 \newbox\errorbox
 %
-{\tentt \global\dimen0 = 3em}% Width of the box.
+{\ttfont \global\dimen0 = 3em}% Width of the box.
 \dimen2 = .55pt % Thickness of rules
 % The text. (`r' is open on the right, `e' somewhat less so on the left.)
 \setbox0 = \hbox{\kern-.75pt \reducedsf \putworderror\kern-1.5pt}
@@ -3691,7 +3768,7 @@ end
 
 % Macros to be used within @titlepage:
 
-\let\subtitlerm=\tenrm
+\let\subtitlerm=\rmfont
 \def\subtitlefont{\subtitlerm \normalbaselineskip = 13pt \normalbaselines}
 
 \parseargdef\title{%
@@ -3896,7 +3973,7 @@ end
 
 
 \message{tables,}
-% Tables -- @table, @ftable, @ktable, @vtable, @item(x).
+% Tables -- @table, @ftable, @vtable, @item(x).
 
 % default indentation of table text
 \newdimen\tableindent \tableindent=.8in
@@ -3908,7 +3985,7 @@ end
 % used internally for \itemindent minus \itemmargin
 \newdimen\itemmax
 
-% Note @table, @ftable, @ktable and @vtable define @item, @itemx, etc., with
+% Note @table, @ftable, and @vtable define @item, @itemx, etc., with
 % these defs.
 % They also define \itemindex
 % to index the item name in whatever manner is desired (perhaps none).
@@ -3976,7 +4053,7 @@ end
 \def\item{\errmessage{@item while not in a list environment}}
 \def\itemx{\errmessage{@itemx while not in a list environment}}
 
-% @table, @ftable, @ktable, @vtable.
+% @table, @ftable, @vtable.
 \envdef\table{%
   \let\itemindex\gobble
   \tablecheck{table}%
@@ -3985,10 +4062,6 @@ end
   \def\itemindex ##1{\doind {fn}{\code{##1}}}%
   \tablecheck{ftable}%
 }
-\envdef\ktable{%
-  \def\itemindex ##1{\doind {ky}{\code{##1}}}%
-  \tablecheck{ktable}%
-}
 \envdef\vtable{%
   \def\itemindex ##1{\doind {vr}{\code{##1}}}%
   \tablecheck{vtable}%
@@ -4032,7 +4105,6 @@ end
 }
 \def\Etable{\endgraf\afterenvbreak}
 \let\Eftable\Etable
-\let\Ektable\Etable
 \let\Evtable\Etable
 \let\Eitemize\Etable
 \let\Eenumerate\Etable
@@ -4786,14 +4858,7 @@ end
 % #1 is \doindex or \docodeindex, #2 the index getting redefined (foo),
 % #3 the target index (bar).
 \def\dosynindex#1#2#3{%
-  % Only do \closeout if we haven't already done it, else we'll end up
-  % closing the target index.
-  \expandafter \ifx\csname donesynindex#2\endcsname \relax
-    % The \closeout helps reduce unnecessary open files; the limit on the
-    % Acorn RISC OS is a mere 16 files.
-    \expandafter\closeout\csname#2indfile\endcsname
-    \expandafter\let\csname donesynindex#2\endcsname = 1
-  \fi
+  \requireopenindexfile{#3}%
   % redefine \fooindfile:
   \expandafter\let\expandafter\temp\expandafter=\csname#3indfile\endcsname
   \expandafter\let\csname#2indfile\endcsname=\temp
@@ -4818,17 +4883,12 @@ end
 %
 \def\indexdummies{%
   \escapechar = `\\     % use backslash in output files.
-  \def\@{@}% change to @@ when we switch to @ as escape char in index files.
-  \def\ {\realbackslash\space }%
-  %
-  % Need these unexpandable (because we define \tt as a dummy)
-  % definitions when @{ or @} appear in index entry text.  Also, more
-  % complicated, when \tex is in effect and \{ is a \delimiter again.
-  % We can't use \lbracecmd and \rbracecmd because texindex assumes
-  % braces and backslashes are used only as delimiters.  Perhaps we
-  % should use @lbracechar and @rbracechar?
-  \def\{{{\tt\char123}}%
-  \def\}{{\tt\char125}}%
+  \definedummyletter\@%
+  \definedummyletter\ %
+  %
+  % For texindex which always views { and } as separators.
+  \def\{{\lbracechar{}}%
+  \def\}{\rbracechar{}}%
   %
   % Do the redefinitions.
   \definedummies
@@ -4836,16 +4896,11 @@ end
 
 % Used for the aux and toc files, where @ is the escape character.
 %
-% For the aux and toc files, @ is the escape character.  So we want to
-% redefine everything using @ as the escape character (instead of
-% \realbackslash, still used for index files).  When everything uses @,
-% this will be simpler.
-%
 \def\atdummies{%
-  \def\@{@@}%
-  \def\ {@ }%
-  \let\{ = \lbraceatcmd
-  \let\} = \rbraceatcmd
+  \definedummyletter\@%
+  \definedummyletter\ %
+  \definedummyletter\{%
+  \definedummyletter\}%
   %
   % Do the redefinitions.
   \definedummies
@@ -4917,6 +4972,7 @@ end
   \definedummyword\TeX
   %
   % Assorted special characters.
+  \definedummyword\atchar
   \definedummyword\arrow
   \definedummyword\bullet
   \definedummyword\comma
@@ -5133,37 +5189,40 @@ end
   \def\LaTeX{LaTeX}%
   \def\TeX{TeX}%
   %
-  % Assorted special characters.
-  % (The following {} will end up in the sort string, but that's ok.)
-  \def\arrow{->}%
-  \def\bullet{bullet}%
-  \def\comma{,}%
-  \def\copyright{copyright}%
-  \def\dots{...}%
-  \def\enddots{...}%
-  \def\equiv{==}%
-  \def\error{error}%
-  \def\euro{euro}%
-  \def\expansion{==>}%
-  \def\geq{>=}%
-  \def\guillemetleft{<<}%
-  \def\guillemetright{>>}%
-  \def\guilsinglleft{<}%
-  \def\guilsinglright{>}%
-  \def\leq{<=}%
-  \def\minus{-}%
-  \def\point{.}%
-  \def\pounds{pounds}%
-  \def\print{-|}%
-  \def\quotedblbase{"}%
-  \def\quotedblleft{"}%
-  \def\quotedblright{"}%
-  \def\quoteleft{`}%
-  \def\quoteright{'}%
-  \def\quotesinglbase{,}%
-  \def\registeredsymbol{R}%
-  \def\result{=>}%
-  \def\textdegree{o}%
+  % Assorted special characters.  \defglyph gives the control sequence a
+  % definition that removes the {} that follows its use.
+  \defglyph\atchar{@}%
+  \defglyph\arrow{->}%
+  \defglyph\bullet{bullet}%
+  \defglyph\comma{,}%
+  \defglyph\copyright{copyright}%
+  \defglyph\dots{...}%
+  \defglyph\enddots{...}%
+  \defglyph\equiv{==}%
+  \defglyph\error{error}%
+  \defglyph\euro{euro}%
+  \defglyph\expansion{==>}%
+  \defglyph\geq{>=}%
+  \defglyph\guillemetleft{<<}%
+  \defglyph\guillemetright{>>}%
+  \defglyph\guilsinglleft{<}%
+  \defglyph\guilsinglright{>}%
+  \defglyph\leq{<=}%
+  \defglyph\lbracechar{\{}%
+  \defglyph\minus{-}%
+  \defglyph\point{.}%
+  \defglyph\pounds{pounds}%
+  \defglyph\print{-|}%
+  \defglyph\quotedblbase{"}%
+  \defglyph\quotedblleft{"}%
+  \defglyph\quotedblright{"}%
+  \defglyph\quoteleft{`}%
+  \defglyph\quoteright{'}%
+  \defglyph\quotesinglbase{,}%
+  \defglyph\rbracechar{\}}%
+  \defglyph\registeredsymbol{R}%
+  \defglyph\result{=>}%
+  \defglyph\textdegree{o}%
   %
   % We need to get rid of all macros, leaving only the arguments (if present).
   % Of course this is not nearly correct, but it is the best we can do for now.
@@ -5178,6 +5237,7 @@ end
   \macrolist
   \let\value\indexnofontsvalue
 }
+\def\defglyph#1#2{\def#1##1{#2}} % see above
 
 
 
@@ -5427,7 +5487,7 @@ end
   % \initial {@}
   % as its first line, TeX doesn't complain about mismatched braces
   % (because it thinks @} is a control sequence).
-  \catcode`\@ = 11
+  \catcode`\@ = 12
   % See comment in \requireopenindexfile.
   \def\indexname{#1}\ifx\indexname\indexisfl\def\indexname{f1}\fi
   \openin 1 \jobname.\indexname s
@@ -5455,7 +5515,7 @@ end
       \let\indexlbrace\{   % Likewise, set these sequences for braces
       \let\indexrbrace\}   % used in the sort key.
       \begindoublecolumns
-      \let\entryorphanpenalty=\indexorphanpenalty
+      \let\entrywidowpenalty=\indexwidowpenalty
       %
       % Read input from the index file line by line.
       \loopdo
@@ -5556,6 +5616,12 @@ end
 \def\entry{%
   \begingroup
     %
+    % For pdfTeX and XeTeX.
+    % The redefinition of \domark stops marks being added in \pdflink to 
+    % preserve coloured links across page boundaries.  Otherwise the marks
+    % would get in the way of \lastbox in \insertindexentrybox.
+    \let\domark\relax
+    %
     % Start a new paragraph if necessary, so our assignments below can't
     % affect previous text.
     \par
@@ -5569,10 +5635,6 @@ end
     \def\*{\unskip\space\ignorespaces}%
     \def\entrybreak{\hfil\break}% An undocumented command
     %
-    % A bit of stretch before each entry for the benefit of balancing
-    % columns.
-    \vskip 0pt plus0.5pt
-    %
     % Swallow the left brace of the text (first parameter):
     \afterassignment\doentry
     \let\temp =
@@ -5606,20 +5668,13 @@ end
       %
       \ifpdf
         \pdfgettoks#1.%
-        \bgroup\let\domark\relax
-          \hskip\skip\thinshrinkable\the\toksA
-        \egroup
-        % The redefinion of \domark stops marks being added in \pdflink to 
-        % preserve coloured links across page boundaries.  Otherwise the marks
-        % would get in the way of \lastbox in \insertindexentrybox.
+        \hskip\skip\thinshrinkable\the\toksA
       \else
         \ifx\XeTeXrevision\thisisundefined
           \hskip\skip\thinshrinkable #1%
         \else
           \pdfgettoks#1.%
-          \bgroup\let\domark\relax
-            \hskip\skip\thinshrinkable\the\toksA
-          \egroup
+          \hskip\skip\thinshrinkable\the\toksA
         \fi
       \fi
     \fi
@@ -5628,11 +5683,10 @@ end
       \global\setbox\entryindexbox=\vbox{\unhbox\boxA}%
     \else
     \global\setbox\entryindexbox=\vbox\bgroup
-      \prevdepth=\entrylinedepth
-      \noindent
       % We want the text of the entries to be aligned to the left, and the
       % page numbers to be aligned to the right.
       %
+      \parindent = 0pt
       \advance\leftskip by 0pt plus 1fil
       \advance\leftskip by 0pt plus -1fill
       \rightskip = 0pt plus -1fil
@@ -5641,8 +5695,6 @@ end
       % if the list of page numbers is long, to be aligned to the right.
       \parfillskip=0pt plus -1fill
       %
-      \hangindent=1em
-      %
       \advance\rightskip by \entryrightmargin
       % Determine how far we can stretch into the margin.
       % This allows, e.g., "Appendix H  GNU Free Documentation License" to
@@ -5662,17 +5714,21 @@ end
       \ifdim\dimen@ > 0.8\dimen@ii   % due to long index text
         \dimen@ = 0.7\dimen@ % Try to split the text roughly evenly
         \dimen@ii = \hsize
-        \advance \dimen@ii by -1em
         \ifnum\dimen@>\dimen@ii
           % If the entry is too long, use the whole line
           \dimen@ = \dimen@ii
         \fi
         \advance\leftskip by 0pt plus 1fill % ragged right
         \advance \dimen@ by 1\rightskip
-        \parshape = 2 0pt \dimen@ 1em \dimen@ii
-        % Ideally we'd add a finite glue at the end of the first line only, but
-        % TeX doesn't seem to provide a way to do such a thing.
+        \parshape = 2 0pt \dimen@ 0em \dimen@ii
+        % Ideally we'd add a finite glue at the end of the first line only,
+        % instead of using \parshape with explicit line lengths, but TeX
+        % doesn't seem to provide a way to do such a thing.
+        %
+        \leftskip = 1em
+        \parindent = -1em
       \fi\fi
+      \indent % start paragraph
       \unhbox\boxA
       %
       % Do not prefer a separate line ending with a hyphen to fewer lines.
@@ -5690,7 +5746,7 @@ end
   \endgroup
   % delay text of entry until after penalty
   \bgroup\aftergroup\insertindexentrybox
-  \entryorphanpenalty
+  \entrywidowpenalty
 }}
 
 \newskip\thinshrinkable
@@ -5698,40 +5754,43 @@ end
 
 \newbox\entryindexbox
 \def\insertindexentrybox{%
-  \copy\entryindexbox
-  % The following gets the depth of the last box.  This is for even
-  % line spacing when entries span several lines.
-  \setbox\dummybox\vbox{%
-    \unvbox\entryindexbox
-    \nointerlineskip
-    \lastbox
-    \global\entrylinedepth=\prevdepth
+  \ourunvbox\entryindexbox
+}
+
+% Use \lastbox to take apart vbox box by box, and add each sub-box
+% to the current vertical list.
+\def\ourunvbox#1{%
+\bgroup % for local binding of \delayedbox
+  % Remove the last box from box #1
+  \global\setbox#1=\vbox{%
+    \unvbox#1%
+    \unskip % remove any glue
+    \unpenalty
+    \global\setbox\interbox=\lastbox
   }%
-  % Note that we couldn't simply \unvbox\entryindexbox followed by 
-  % \nointerlineskip\lastbox to remove the last box and then reinstate it, 
-  % because this resets how far the box has been \moveleft'ed to 0.  \unvbox
-  % doesn't affect \prevdepth either.
+  \setbox\delayedbox=\box\interbox
+  \ifdim\ht#1=0pt\else
+    \ourunvbox#1 % Repeat on what's left of the box
+    \nobreak
+  \fi
+  \box\delayedbox
+\egroup
 }
-\newdimen\entrylinedepth
+\newbox\delayedbox
+\newbox\interbox
 
 % Default is no penalty
-\let\entryorphanpenalty\egroup
+\let\entrywidowpenalty\egroup
 
 % Used from \printindex.  \firsttoken should be the first token
 % after the \entry.  If it's not another \entry, we are at the last
 % line of a group of index entries, so insert a penalty to discourage
-% orphaned index entries.
-\long\def\indexorphanpenalty{%
+% widowed index entries.
+\long\def\indexwidowpenalty{%
   \def\isentry{\entry}%
   \ifx\firsttoken\isentry
   \else
-    \unskip\penalty 9000
-    % The \unskip here stops breaking before the glue.  It relies on the
-    % \vskip above being there, otherwise there is an error
-    % "You can't use `\unskip' in vertical mode".  There has to be glue
-    % in the current vertical list that hasn't been added to the
-    % "current page".  See Chapter 24 of the TeXbook.  This contradicts
-    % Section 8.3.7 in "TeX by Topic," though.
+    \penalty 9000
   \fi
   \egroup % now comes the box added with \aftergroup
 }
@@ -5771,8 +5830,6 @@ end
 
 \newbox\partialpage
 \newdimen\doublecolumnhsize
-\newdimen\doublecolumntopgap
-\doublecolumntopgap = 0pt
 
 % Use inside an output routine to save \topmark and \firstmark
 \def\savemarks{%
@@ -5855,12 +5912,10 @@ end
   %
   % Double the \vsize as well.  (We don't need a separate register here,
   % since nobody clobbers \vsize.)
-  \global\doublecolumntopgap = \topskip
-  \global\advance\doublecolumntopgap by -1\baselineskip
-  \advance\vsize by -1\doublecolumntopgap
   \vsize = 2\vsize
-  \topskip=0pt
-  \global\entrylinedepth=0pt\relax
+  %
+  % For the benefit of balancing columns
+  \advance\baselineskip by 0pt plus 0.5pt
 }
 
 % The double-column output routine for all double-column pages except
@@ -5890,9 +5945,7 @@ end
   %
   \hsize = \doublecolumnhsize
   \wd0=\hsize \wd2=\hsize
-  \vbox{%
-    \vskip\doublecolumntopgap
-    \hbox to\txipagewidth{\box0\hfil\box2}}%
+  \hbox to\txipagewidth{\box0\hfil\box2}%
 }
 
 
@@ -5959,51 +6012,44 @@ end
   \dimen@ = \ht0
   \advance\dimen@ by \topskip
   \advance\dimen@ by-\baselineskip
-  \ifdim\dimen@<14\baselineskip
+  \ifdim\dimen@<5\baselineskip
     % Don't split a short final column in two.
     \setbox2=\vbox{}%
   \else
     \divide\dimen@ by 2 % target to split to
     \dimen@ii = \dimen@
     \splittopskip = \topskip
-    % Loop until the second column is no higher than the first
+    % Loop until left column is at least as high as the right column.
     {%
       \vbadness = 10000
       \loop
         \global\setbox3 = \copy0
         \global\setbox1 = \vsplit3 to \dimen@
-        % Remove glue from bottom of first column to
-        % make sure it is higher than the second.
-        \global\setbox1 = \vbox{\unvbox1\unpenalty\unskip}%
-      \ifdim\ht3>\ht1
+      \ifdim\ht1<\ht3
         \global\advance\dimen@ by 1pt
       \repeat
     }%
+    % Now the left column is in box 1, and the right column in box 3.
+    % Check whether the left column has come out higher than the page itself.  
+    % (Note that we have doubled \vsize for the double columns, so
+    % the actual height of the page is 0.5\vsize).
     \ifdim2\ht1>\vsize
-      % The left column has come out longer than the page itself.  (Note
-      % that we have doubled \vsize for the double columns, so
-      % the actual height of the page is 0.5\vsize).  Just split the last
-      % of the double column material roughly in half.
+      % Just split the last of the double column material roughly in half.
       \setbox2=\box0
       \setbox0 = \vsplit2 to \dimen@ii
-      \setbox0=\vbox to\dimen@ii{\unvbox0}%
-      \setbox2=\vbox to\dimen@ii{\unvbox2}%
+      \setbox0=\vbox to \dimen@ii {\unvbox0\vfill}%
+      \setbox2=\vbox to \dimen@ii {\unvbox2\vfill}%
     \else
-      \multiply\dimen@ii by 5
-      \divide\dimen@ii by 4
-      \global\setbox3 = \copy0
-      \global\setbox1 = \vsplit3 to \dimen@ii
-      \global\setbox\balancedcolumns=\vbox{\pagesofar}%
-      \ifdim\ht3<\dimen@ii
+      % Compare the heights of the two columns.
+      \ifdim4\ht1>5\ht3
         % Column heights are too different, so don't make their bottoms
-        % flush with each other.  The glue at the end of the second column
-        % allows a second column to stretch, reducing the difference in
-        % height between the two.
-        \setbox0=\vbox to\dimen@{\unvbox1\vfill}%
-        \setbox2=\vbox to\dimen@{\unvbox3\vskip 0pt plus 0.3\ht0}%
+        % flush with each other.
+        \setbox2=\vbox to \ht1 {\unvbox3\vfill}%
+        \setbox0=\vbox to \ht1 {\unvbox1\vfill}%
       \else
-        \setbox0=\vbox to\dimen@{\unvbox1}%
-        \setbox2=\vbox to\dimen@{\unvbox3}%
+        % Make column bottoms flush with each other.
+        \setbox2=\vbox to\ht1{\unvbox3\unskip}%
+        \setbox0=\vbox to\ht1{\unvbox1\unskip}%
       \fi
     \fi
   \fi
@@ -7874,7 +7920,7 @@ end
     \fi           % no return type
     #3% output function name
   }%
-  {\rm\enskip}% hskip 0.5 em of \tenrm
+  {\rm\enskip}% hskip 0.5 em of \rmfont
   %
   \boldbrax
   % arguments will be output next, if any.
@@ -8838,8 +8884,8 @@ end
   \ifpdf
     % For pdfTeX and LuaTeX
     {\indexnofonts
-     \turnoffactive
      \makevalueexpandable
+     \turnoffactive
      % This expands tokens, so do it after making catcode changes, so _
      % etc. don't get their TeX definitions.  This ignores all spaces in
      % #4, including (wrongly) those in the middle of the filename.
@@ -8847,19 +8893,18 @@ end
      %
      % This (wrongly) does not take account of leading or trailing
      % spaces in #1, which should be ignored.
-     \edef\pdfxrefdest{#1}%
-     \ifx\pdfxrefdest\empty
-       \def\pdfxrefdest{Top}% no empty targets
-     \else
-       \txiescapepdf\pdfxrefdest  % escape PDF special chars
+     \setpdfdestname{#1}%
+     %
+     \ifx\pdfdestname\empty
+       \def\pdfdestname{Top}% no empty targets
      \fi
      %
      \leavevmode
      \startlink attr{/Border [0 0 0]}%
      \ifnum\filenamelength>0
-       goto file{\the\filename.pdf} name{\pdfxrefdest}%
+       goto file{\the\filename.pdf} name{\pdfdestname}%
      \else
-       goto name{\pdfmkpgn{\pdfxrefdest}}%
+       goto name{\pdfmkpgn{\pdfdestname}}%
      \fi
     }%
     \setcolor{\linkcolor}%
@@ -8868,8 +8913,8 @@ end
     \else
       % For XeTeX
       {\indexnofonts
-       \turnoffactive
        \makevalueexpandable
+       \turnoffactive
        % This expands tokens, so do it after making catcode changes, so _
        % etc. don't get their TeX definitions.  This ignores all spaces in
        % #4, including (wrongly) those in the middle of the filename.
@@ -8877,32 +8922,27 @@ end
        %
        % This (wrongly) does not take account of leading or trailing
        % spaces in #1, which should be ignored.
-       \iftxiuseunicodedestname
-         \def\pdfxrefdest{#1}% Pass through Unicode characters.
-       \else
-         \edef\pdfxrefdest{#1}% Replace Unicode characters to ASCII.
-       \fi
-       \ifx\pdfxrefdest\empty
-         \def\pdfxrefdest{Top}% no empty targets
-       \else
-         \txiescapepdf\pdfxrefdest  % escape PDF special chars
+       \setpdfdestname{#1}%
+       %
+       \ifx\pdfdestname\empty
+         \def\pdfdestname{Top}% no empty targets
        \fi
        %
        \leavevmode
        \ifnum\filenamelength>0
-         % By the default settings,
+         % With default settings,
          % XeTeX (xdvipdfmx) replaces link destination names with integers.
          % In this case, the replaced destination names of
-         % remote PDF cannot be known. In order to avoid replacement,
-         % you can use commandline option `-C 0x0010' for xdvipdfmx.
+         % remote PDFs are no longer known.  In order to avoid a replacement,
+         % you can use xdvipdfmx's command line option `-C 0x0010'.
          % If you use XeTeX 0.99996+ (TeX Live 2016+),
-         % the commandline option is not neccesary
-         % because we can use `dvipdfmx:config' special.
+         % this command line option is no longer necessary
+         % because we can use the `dvipdfmx:config' special.
          \special{pdf:bann << /Border [0 0 0] /Type /Annot /Subtype /Link /A
-           << /S /GoToR /F (\the\filename.pdf) /D (name\pdfxrefdest) >> >>}%
+           << /S /GoToR /F (\the\filename.pdf) /D (\pdfdestname) >> >>}%
        \else
          \special{pdf:bann << /Border [0 0 0] /Type /Annot /Subtype /Link /A
-           << /S /GoTo /D (name\pdfxrefdest) >> >>}%
+           << /S /GoTo /D (\pdfdestname) >> >>}%
        \fi
       }%
       \setcolor{\linkcolor}%
@@ -9809,9 +9849,9 @@ directory should work if nowhere else does.}
   \global\righthyphenmin = #3\relax
 }
 
-% XeTeX and LuaTeX can handle native Unicode.
-% Their default I/O is UTF-8 sequence instead of byte-wise.
-% Other TeX engine (pdfTeX etc.) I/O is byte-wise.
+% XeTeX and LuaTeX can handle Unicode natively.
+% Their default I/O uses UTF-8 sequences instead of a byte-wise operation.
+% Other TeX engines' I/O (pdfTeX, etc.) is byte-wise.
 %
 \newif\iftxinativeunicodecapable
 \newif\iftxiusebytewiseio
@@ -9935,14 +9975,15 @@ directory should work if nowhere else does.}
   %
   \else \ifx \declaredencoding \utfeight
      \iftxinativeunicodecapable
-       % For native Unicode (XeTeX and LuaTeX)
+       % For native Unicode handling (XeTeX and LuaTeX)
        \nativeunicodechardefs
      \else
-       % For UTF-8 byte sequence (TeX, eTeX and pdfTeX)
+       % For treating UTF-8 as byte sequences (TeX, eTeX and pdfTeX)
        \setnonasciicharscatcode\active
        % since we already invoked \utfeightchardefs at the top level
-       % (below), do not re-invoke it, then our check for duplicated
-       % definitions triggers.  Making non-ascii chars active is enough.
+       % (below), do not re-invoke it, otherwise our check for duplicated
+       % definitions gets triggered.  Making non-ascii chars active is
+       % sufficient.
      \fi
   %
   \else
@@ -9953,6 +9994,18 @@ directory should work if nowhere else does.}
   \fi % latone
   \fi % lattwo
   \fi % ascii
+  %
+  \ifx\XeTeXrevision\thisisundefined
+  \else
+    \ifx \declaredencoding \utfeight
+    \else
+      \ifx \declaredencoding \ascii
+      \else
+        \message{Warning: XeTeX with non-UTF-8 encodings cannot handle %
+        non-ASCII characters in auxiliary files.}%
+      \fi
+    \fi
+  \fi
 }
 
 % emacs-page
@@ -9984,18 +10037,18 @@ directory should work if nowhere else does.}
   \gdefchar^^a0{\tie}
   \gdefchar^^a1{\exclamdown}
   \gdefchar^^a2{{\tcfont \char162}} % cent
-  \gdefchar^^a3{\pounds}
+  \gdefchar^^a3{\pounds{}}
   \gdefchar^^a4{{\tcfont \char164}} % currency
   \gdefchar^^a5{{\tcfont \char165}} % yen
   \gdefchar^^a6{{\tcfont \char166}} % broken bar
   \gdefchar^^a7{\S}
   \gdefchar^^a8{\"{}}
-  \gdefchar^^a9{\copyright}
+  \gdefchar^^a9{\copyright{}}
   \gdefchar^^aa{\ordf}
-  \gdefchar^^ab{\guillemetleft}
+  \gdefchar^^ab{\guillemetleft{}}
   \gdefchar^^ac{\ensuremath\lnot}
   \gdefchar^^ad{\-}
-  \gdefchar^^ae{\registeredsymbol}
+  \gdefchar^^ae{\registeredsymbol{}}
   \gdefchar^^af{\={}}
   %
   \gdefchar^^b0{\textdegree}
@@ -10009,7 +10062,7 @@ directory should work if nowhere else does.}
   \gdefchar^^b8{\cedilla\ }
   \gdefchar^^b9{$^1$}
   \gdefchar^^ba{\ordm}
-  \gdefchar^^bb{\guillemetright}
+  \gdefchar^^bb{\guillemetright{}}
   \gdefchar^^bc{$1\over4$}
   \gdefchar^^bd{$1\over2$}
   \gdefchar^^be{$3\over4$}
@@ -10089,7 +10142,7 @@ directory should work if nowhere else does.}
   % Encoding is almost identical to Latin1.
   \latonechardefs
   %
-  \gdefchar^^a4{\euro}
+  \gdefchar^^a4{\euro{}}
   \gdefchar^^a6{\v S}
   \gdefchar^^a8{\v s}
   \gdefchar^^b4{\v Z}
@@ -10118,7 +10171,7 @@ directory should work if nowhere else does.}
   \gdefchar^^ae{\v Z}
   \gdefchar^^af{\dotaccent Z}
   %
-  \gdefchar^^b0{\textdegree}
+  \gdefchar^^b0{\textdegree{}}
   \gdefchar^^b1{\ogonek{a}}
   \gdefchar^^b2{\ogonek{ }}
   \gdefchar^^b3{\l}
@@ -10290,8 +10343,9 @@ directory should work if nowhere else does.}
 \def\U#1{%
   \expandafter\ifx\csname uni:#1\endcsname \relax
     \iftxinativeunicodecapable
-      % Any Unicode characters can be used by native Unicode.
-      % However, if the font does not have the glyph, the letter will miss.
+      % All Unicode characters can be used if native Unicode handling is
+      % active.  However, if the font does not have the glyph,
+      % letters are missing.
       \begingroup
         \uccode`\.="#1\relax
         \uppercase{.}
@@ -10314,9 +10368,9 @@ directory should work if nowhere else does.}
 \def\UTFviiiFourOctetsName#1#2#3#4{%
   \csname u8:#1\string #2\string #3\string #4\endcsname}%
 
-% For UTF-8 byte sequence (TeX, e-TeX and pdfTeX)
-% Definition macro to replace the Unicode character
-% Definition macro that is used by @U command
+% For UTF-8 byte sequences (TeX, e-TeX and pdfTeX),
+% provide a definition macro to replace a Unicode character;
+% this gets used by the @U command
 %
 \begingroup
   \catcode`\"=12
@@ -10404,8 +10458,8 @@ directory should work if nowhere else does.}
     \uppercase{\gdef\UTFviiiTmp{#2#3#4}}}
 \endgroup
 
-% For native Unicode (XeTeX and LuaTeX)
-% Definition macro that is set catcode other non global
+% For native Unicode handling (XeTeX and LuaTeX),
+% provide a definition macro that sets a catcode to `other' non-globally
 %
 \def\DeclareUnicodeCharacterNativeOther#1#2{%
   \catcode"#1=\other
@@ -10429,18 +10483,18 @@ directory should work if nowhere else does.}
   \DeclareUnicodeCharacter{00A0}{\tie}%
   \DeclareUnicodeCharacter{00A1}{\exclamdown}%
   \DeclareUnicodeCharacter{00A2}{{\tcfont \char162}}% 0242=cent
-  \DeclareUnicodeCharacter{00A3}{\pounds}%
+  \DeclareUnicodeCharacter{00A3}{\pounds{}}%
   \DeclareUnicodeCharacter{00A4}{{\tcfont \char164}}% 0244=currency
   \DeclareUnicodeCharacter{00A5}{{\tcfont \char165}}% 0245=yen
   \DeclareUnicodeCharacter{00A6}{{\tcfont \char166}}% 0246=brokenbar
   \DeclareUnicodeCharacter{00A7}{\S}%
   \DeclareUnicodeCharacter{00A8}{\"{ }}%
-  \DeclareUnicodeCharacter{00A9}{\copyright}%
+  \DeclareUnicodeCharacter{00A9}{\copyright{}}%
   \DeclareUnicodeCharacter{00AA}{\ordf}%
-  \DeclareUnicodeCharacter{00AB}{\guillemetleft}%
+  \DeclareUnicodeCharacter{00AB}{\guillemetleft{}}%
   \DeclareUnicodeCharacter{00AC}{\ensuremath\lnot}%
   \DeclareUnicodeCharacter{00AD}{\-}%
-  \DeclareUnicodeCharacter{00AE}{\registeredsymbol}%
+  \DeclareUnicodeCharacter{00AE}{\registeredsymbol{}}%
   \DeclareUnicodeCharacter{00AF}{\={ }}%
   %
   \DeclareUnicodeCharacter{00B0}{\ringaccent{ }}%
@@ -10454,7 +10508,7 @@ directory should work if nowhere else does.}
   \DeclareUnicodeCharacter{00B8}{\cedilla{ }}%
   \DeclareUnicodeCharacter{00B9}{$^1$}%
   \DeclareUnicodeCharacter{00BA}{\ordm}%
-  \DeclareUnicodeCharacter{00BB}{\guillemetright}%
+  \DeclareUnicodeCharacter{00BB}{\guillemetright{}}%
   \DeclareUnicodeCharacter{00BC}{$1\over4$}%
   \DeclareUnicodeCharacter{00BD}{$1\over2$}%
   \DeclareUnicodeCharacter{00BE}{$3\over4$}%
@@ -10926,36 +10980,36 @@ directory should work if nowhere else does.}
   % Punctuation
   \DeclareUnicodeCharacter{2013}{--}%
   \DeclareUnicodeCharacter{2014}{---}%
-  \DeclareUnicodeCharacter{2018}{\quoteleft}%
-  \DeclareUnicodeCharacter{2019}{\quoteright}%
-  \DeclareUnicodeCharacter{201A}{\quotesinglbase}%
-  \DeclareUnicodeCharacter{201C}{\quotedblleft}%
-  \DeclareUnicodeCharacter{201D}{\quotedblright}%
-  \DeclareUnicodeCharacter{201E}{\quotedblbase}%
+  \DeclareUnicodeCharacter{2018}{\quoteleft{}}%
+  \DeclareUnicodeCharacter{2019}{\quoteright{}}%
+  \DeclareUnicodeCharacter{201A}{\quotesinglbase{}}%
+  \DeclareUnicodeCharacter{201C}{\quotedblleft{}}%
+  \DeclareUnicodeCharacter{201D}{\quotedblright{}}%
+  \DeclareUnicodeCharacter{201E}{\quotedblbase{}}%
   \DeclareUnicodeCharacter{2020}{\ensuremath\dagger}%
   \DeclareUnicodeCharacter{2021}{\ensuremath\ddagger}%
-  \DeclareUnicodeCharacter{2022}{\bullet}%
+  \DeclareUnicodeCharacter{2022}{\bullet{}}%
   \DeclareUnicodeCharacter{202F}{\thinspace}%
-  \DeclareUnicodeCharacter{2026}{\dots}%
-  \DeclareUnicodeCharacter{2039}{\guilsinglleft}%
-  \DeclareUnicodeCharacter{203A}{\guilsinglright}%
+  \DeclareUnicodeCharacter{2026}{\dots{}}%
+  \DeclareUnicodeCharacter{2039}{\guilsinglleft{}}%
+  \DeclareUnicodeCharacter{203A}{\guilsinglright{}}%
   %
-  \DeclareUnicodeCharacter{20AC}{\euro}%
+  \DeclareUnicodeCharacter{20AC}{\euro{}}%
   %
-  \DeclareUnicodeCharacter{2192}{\expansion}%
-  \DeclareUnicodeCharacter{21D2}{\result}%
+  \DeclareUnicodeCharacter{2192}{\expansion{}}%
+  \DeclareUnicodeCharacter{21D2}{\result{}}%
   %
   % Mathematical symbols
   \DeclareUnicodeCharacter{2200}{\ensuremath\forall}%
   \DeclareUnicodeCharacter{2203}{\ensuremath\exists}%
   \DeclareUnicodeCharacter{2208}{\ensuremath\in}%
-  \DeclareUnicodeCharacter{2212}{\minus}%
+  \DeclareUnicodeCharacter{2212}{\minus{}}%
   \DeclareUnicodeCharacter{2217}{\ast}%
   \DeclareUnicodeCharacter{221E}{\ensuremath\infty}%
   \DeclareUnicodeCharacter{2225}{\ensuremath\parallel}%
   \DeclareUnicodeCharacter{2227}{\ensuremath\wedge}%
   \DeclareUnicodeCharacter{2229}{\ensuremath\cap}%
-  \DeclareUnicodeCharacter{2261}{\equiv}%
+  \DeclareUnicodeCharacter{2261}{\equiv{}}%
   \DeclareUnicodeCharacter{2264}{\ensuremath\leq}%
   \DeclareUnicodeCharacter{2265}{\ensuremath\geq}%
   \DeclareUnicodeCharacter{2282}{\ensuremath\subset}%
@@ -11111,8 +11165,8 @@ directory should work if nowhere else does.}
 \newif\ifpassthroughchars
 \passthroughcharsfalse
 
-% For native Unicode (XeTeX and LuaTeX)
-% Definition macro to replace / pass-through the Unicode character
+% For native Unicode handling (XeTeX and LuaTeX),
+% provide a definition macro to replace/pass-through a Unicode character
 %
 \def\DeclareUnicodeCharacterNative#1#2{%
   \catcode"#1=\active
@@ -11135,21 +11189,22 @@ directory should work if nowhere else does.}
   \endgroup
 }
 
-% Native Unicode (XeTeX and LuaTeX) character replacing definitions
-% It makes the setting that replace the Unicode characters.
+% Native Unicode handling (XeTeX and LuaTeX) character replacing definition.
+% It activates the setting that replaces Unicode characters.
 \def\nativeunicodechardefs{%
   \let\DeclareUnicodeCharacter\DeclareUnicodeCharacterNative
   \unicodechardefs
 }
 
-% For native Unicode (XeTeX and LuaTeX).  Make the character token expand
+% For native Unicode handling (XeTeX and LuaTeX),
+% make the character token expand
 % to the sequences given in \unicodechardefs for printing.
 \def\DeclareUnicodeCharacterNativeAtU#1#2{%
   \def\UTFAtUTmp{#2}
   \expandafter\globallet\csname uni:#1\endcsname \UTFAtUTmp
 }
 
-% Native Unicode (XeTeX and LuaTeX) @U command definitions
+% @U command definitions for native Unicode handling (XeTeX and LuaTeX).
 \def\nativeunicodechardefsatu{%
   \let\DeclareUnicodeCharacter\DeclareUnicodeCharacterNativeAtU
   \unicodechardefs
@@ -11160,7 +11215,7 @@ directory should work if nowhere else does.}
    \relax
 }
 
-% define all the unicode characters we know about, for the sake of @U.
+% define all Unicode characters we know about, for the sake of @U.
 \iftxinativeunicodecapable
   \nativeunicodechardefsatu
 \else
@@ -11636,7 +11691,4 @@ directory should work if nowhere else does.}
 
 @c vim:sw=2:
 
-@ignore
-   arch-tag: e1b36e32-c96e-4135-a41a-0b2efa2ea115
-@end ignore
 @enablebackslashhack