From fed27f633aadbacbd3d1221da7993fed8d4efffe Mon Sep 17 00:00:00 2001
From: Norbert Preining <norbert@preining.info>
Date: Sun, 15 Sep 2019 03:00:57 +0000
Subject: CTAN sync 201909150300

---
 macros/latex-dev/base/ltnews28.tex | 365 +++++++++++++++++++++++++++++++++++++
 1 file changed, 365 insertions(+)
 create mode 100644 macros/latex-dev/base/ltnews28.tex

(limited to 'macros/latex-dev/base/ltnews28.tex')

diff --git a/macros/latex-dev/base/ltnews28.tex b/macros/latex-dev/base/ltnews28.tex
new file mode 100644
index 0000000000..c8af784081
--- /dev/null
+++ b/macros/latex-dev/base/ltnews28.tex
@@ -0,0 +1,365 @@
+% \iffalse meta-comment
+%
+% Copyright (C) 2017-2019
+% The LaTeX3 Project and any individual authors listed elsewhere
+% in this file.
+%
+% This file is part of the LaTeX base system.
+% -------------------------------------------
+%
+% It may be distributed and/or modified under the
+% conditions of the LaTeX Project Public License, either version 1.3c
+% of this license or (at your option) any later version.
+% The latest version of this license is in
+%    http://www.latex-project.org/lppl.txt
+% and version 1.3c or later is part of all distributions of LaTeX
+% version 2008 or later.
+%
+% This file has the LPPL maintenance status "maintained".
+%
+% The list of all files belonging to the LaTeX base distribution is
+% given in the file `manifest.txt'. See also `legal.txt' for additional
+% information.
+%
+% The list of derived (unpacked) files belonging to the distribution
+% and covered by LPPL is defined by the unpacking scripts (with
+% extension .ins) which are part of the distribution.
+%
+% \fi
+% Filename: ltnews28.tex
+%
+% This is issue 28 of LaTeX News.
+
+\documentclass{ltnews}
+\usepackage[T1]{fontenc}
+
+\usepackage{lmodern,url,hologo}
+
+\providecommand\acro[1]{\textsc{#1}}
+\providecommand\meta[1]{$\langle$\textit{#1}$\rangle$}
+
+
+\publicationmonth{April}
+\publicationyear{2018}
+
+\publicationissue{28}
+
+\begin{document}
+
+\maketitle
+\tableofcontents
+
+\setlength\rightskip{0pt plus 3em}
+
+\section{A new home for \LaTeXe{} sources}
+
+In the past the development version of the \LaTeXe{} source files has
+been managed in a Subversion source control system with read access
+for the public. This way it was possible to download in an emergency
+the latest version even before it was released to CTAN and made its
+way into the various distributions.
+
+We have recently changed this setup and now manage the sources using
+Git and placed the master sources on GitHub at
+\begin{quote}
+\url{https://github.com/latex3/latex2e}
+\end{quote}
+where we already store the sources
+for \pkg{expl3} and other work. As before, direct write access is restricted
+to \LaTeX{} Project Team members, but everything is publicly accessible
+including the ability to download, clone (using Git) or checkout
+(using SVN). More details are given in~\cite{Mittelbach:TB39-1}.
+
+\section{Bug reports for core \LaTeXe{}}
+
+For more than two decades we used GNATS, an open source bug tracking
+system developed by the FSF. While that has served us well in the past
+it started to show its age more and more. So as part of this move we
+also decided to finally retire the old \LaTeX{} bug database and replace
+it with the standard ``Issue Tracker'' available at Github.
+
+The requirements and the workflow for reporting a bug in the core
+\LaTeX{} software is documented at
+\begin{quote}
+\url{https://www.latex-project.org/bugs/}
+\end{quote}
+and with further details also discussed in~\cite{Mittelbach:TB39-1}.
+
+
+\section{UTF-8: the new default input encoding}
+
+The first \TeX{} implementations only supported reading 7-bit
+\acro{ascii} files---any accented or otherwise ``special'' character
+had to be entered using commands, if it could be represented at
+all. For example to obtain an ``\"a'' one would enter \verb=\"a=, and to
+typeset a ``\ss'' the command \verb=\ss=. Furthermore fonts at that
+time had 128 glyphs inside, holding the \acro{ascii} characters, some
+accents to build composite glyphs from a letter and an accent, and a
+few special symbols such as parentheses, etc.
+
+With 8-bit \TeX{} engines such as \hologo{pdfTeX} this situation changed
+somewhat: it was now possible to process 8-bit files, i.e., files that
+could encode 256 different characters. However, 256 is still a fairly
+small number and with this limitation it is only possible to encode a
+few languages and for other languages one would need to change the
+encoding (i.e., interpret the character positions 0--255 in a
+different way). The first code points 0--127 were essentially normed
+(corresponding to \acro{ascii}) while the second half 128--255 would
+vary by holding different accented characters to support a certain set
+of languages.
+
+Each computer used one of these encodings when storing or interpreting
+files and as long as two computers used the same encoding it was
+(easily) possible to exchange files between them and have them
+interpreted and processed correctly.
+
+But different computers may have used different encodings and given
+that a computer file is simply a sequence of bytes with no indication for
+which encoding is intended, chaos could easily happen and has
+happened. For example, the German word ``Gr\"o\ss e'' (height) entered on a
+German keyboard could show up as ``Gr\v T\`ae'' on a different
+computer using a different encoding by default.
+
+So in summmary the situation wasn't at all good and it was clear in
+the early nineties that \LaTeXe{} (that was being developed to provide
+a \LaTeX{} version usable across the world) had to provide a solution
+to this issue.
+
+The \LaTeXe{} answer was the introduction of the \package{inputenc}
+package~\cite{Mittelbach:Brno95} through which it is possible to
+provide support for multiple encodings. It also allows to correctly
+process a file written in one encoding on a computer using a different
+encoding and even supports documents where the encoding changes
+midway.
+
+Since the first release of \LaTeXe{} in 1994, \LaTeX{} documents that
+used any characters outside \acro{ascii} in the source (i.e. any
+characters in the range of 128--255) were supposed to load
+\package{inputenc} and specify in which file encoding they were
+written and stored.
+%
+If the \package{inputenc} package was not loaded then \LaTeX{} used a
+``raw'' encoding which essentially took each byte from the input file
+and typeset the glyph that happened to be in that position in the
+current font---something that sometimes produces the right result but
+often enough will not.
+
+In 1992 Ken Thompson and Rob Pike developed the UTF-8 encoding scheme
+which enables the encoding of all Unicode characters within 8-bit sequences.
+Over time this encoding has gradually taken over the world,
+replacing the legacy 8-bit encodings used before. These days all major
+computer operating systems use UTF-8 to store their files and it
+requires some effort to explicitly store files in one of the legacy
+encodings.
+
+As a result, whenever \LaTeX{} users want to use any accented
+characters from their keyboard (instead of resorting to \verb=\"a= and
+the like) they always have to use
+\begin{verbatim}
+  \usepackage[utf8]{inputenc}
+\end{verbatim}
+in the preamble of their documents as otherwise \LaTeX{} will produce
+gibberish.
+
+\subsection{The new default}
+
+With this release, the default encoding for \LaTeX\ files has been
+changed from the ``fall through raw'' encoding to UTF-8 if used with
+classic \TeX\ or \hologo{pdfTeX}. The implementation is essentially
+the same as the existing UTF-8 support from
+\verb|\usepackage[utf8]{inputenc}|.  
+
+The \hologo{LuaTeX} and \hologo{XeTeX} engines always supported the
+UTF-8 encoding as their native (and only) input encoding, so with
+these engines \package{inputenc} was always a no-op.
+
+This means that with new documents one can assume UTF-8 input and it
+is no longer required to always specify
+\verb|\usepackage[utf8]{inputenc}|. But if this line is present it
+will not hurt either.
+
+
+\subsection{Compatibility}
+
+For most existing documents this change will be transparent:
+\begin{itemize}
+\item documents using only \acro{ascii} in the input file and
+  accessing accented characters via commands;
+\item documents that specified the encoding of their file via an
+  option to the \package{inputenc} package and then used 8-bit
+  characters in that encoding;
+\item documents that already had been stored in UTF-8 (whether or not
+  specifying this via \package{inputenc}).
+\end{itemize}
+Only documents that have been stored in a legacy encoding and used
+accented letters from the keyboard \emph{without} loading
+\package{inputenc} (relying on the similarities between the input used
+and the T1 font encoding) are affected.
+
+These documents will now generate an error that they contain invalid
+UTF-8 sequences.  However, such documents may be easily processed by
+adding the new command \verb|\UseRawInputEncoding| as the first line
+of the file. This will re-instate the previous ``raw'' encoding
+default.
+
+\verb|\UseRawInputEncoding| may also be used on the command line to
+process existing files without requiring the file to be edited
+\begin{verbatim}
+  pdflatex '\UseRawInputEncoding \input'  file
+\end{verbatim}
+will process the file using the previous default encoding.
+
+Possible alternatives are reencoding the file to UTF-8 using a tool
+(such as recode or iconv or an editor) or adding the line
+\begin{flushleft}
+\verb=  \usepackage[=\meta{encoding}\verb=]{inputenc}=
+\end{flushleft}
+to the preamble specifying the \meta{encoding} that fits the file
+encoding.  In many cases this will be \texttt{latin1} or
+\texttt{cp1252}. For other encoding names and their meaning see the
+\package{inputenc} documentation.
+
+As usual, this change may also be reverted via the more general
+\package{latexrelease} package mechanism, by speciying a release date
+earlier than this release.
+
+
+\subsection{BOM: byte order mark handling}
+
+When using Unicode the first bytes of a file may be a, so called, BOM
+character (byte order mark) to indicate the byte oder used in the
+file. While this is not required with UTF-8 encoded files (where the
+byte order is known) it is nevertheless allowed by the standard and
+some editors add that byte sequence to the beginning of a file. In the
+past such files would have generated a ``Missing begin document''
+error or displayed strange characters when loaded at a later stage.
+
+With the addition of UTF-8 support to the kernel it is now possible to
+identify and ignore such BOMs characters even before
+\verb=\documentclass= so that these issues will no longer be showing
+up.
+
+
+
+\section[A general rollback concept]
+        {A general rollback concept for packages and classes}
+
+  In 2015 a rollback concept for the \LaTeX{} kernel was introduced.
+  Providing this feature allowed us to make corrections to the
+  software (which more or less didn't happen for nearly two decades)
+  while continuing to maintain backward compatibility to the highest
+  degree.
+  
+  In this release we have now extended this concept to
+  the world of packages and classes which was not covered
+  initially. As the classes and the extension packages have different
+  requirements compared to the kernel, the approach is different (and
+  simplified). This should make it easy for package developers to
+  apply it to their packages and authors to use when necessary.
+
+  The documentation of this new feature is given in an article
+  submitted to TUGboat and also available from our
+  website~\cite{Mittelbach:TB39-2}.
+
+
+\section[Integration of \pkg{remreset} and \pkg{chngcntr} packages]
+         {Integration of \pkg{remreset} and \pkg{chngcntr} packages 
+         into the kernel}
+
+With the optional argument to \cs{newcounter} \LaTeX{} offers to
+automatically reset counters when some counter is stepped, e.g.,
+stepping a \texttt{chapter} counter resets the \texttt{section}
+counter (and recursively all other heading counters). However, what
+was until now missing was a way to undo such a link between counters
+or to link two counters after they have been defined.
+
+This can be now be done with \cs{counterwithin} and \cs{counterwithout},
+respectively. In the past one had to load the \pkg{chngcntr} package
+for this. For the programming level we also added
+\cs{@removefromreset} as the counterpart of the already existing
+\cs{@addtoreset} command. Up to now this was offered by the
+\pkg{remreset} package.
+
+\section{Testing for undefined commands}
+\LaTeX\ packages often use a test \verb|\@ifundefined| to test if a command
+is defined. Unfortunately this had the side effect of \emph{defining}
+the command to \verb|\relax| in the case that it had no definition.
+ The new release uses a modified definition
+(using extra testing possibilities available in \hologo{eTeX}. The new definition
+is more natural, however code that was relying on the side effect of the
+command being tested being defined if it was previously undefined may have to add
+\verb|\let\|\meta{command}\verb|\relax|.
+
+
+\section{Changes to packages in the tools category}
+
+\subsection{\LaTeX{} table columns with fixed widths}
+
+Frank published a short paper in
+TUGboat~\cite{Mittelbach:TB38-2-213} on producing tables that have
+columns with fixed widths. The outlined approach using column
+specifiers ``\texttt{w}'' and ``\texttt{W}'' has now been integrated
+into the \pkg{array} package.
+
+\subsection{Obscure overprinting with \pkg{multicol} fixed}
+
+A rather peculiar bug was reported on StackExchange for
+\pkg{multicol}. If the column/page breaking was fully controlled by
+the user (through \cs{columnbreak}) instead of letting the environment
+do its job and if then more \cs{columnbreak} commands showed up on the
+last page then the balancing algorithm was thrown off track.
+As a result some parts of the columns did overprint each other.
+
+The fix required a redesign of the output routines used by
+\pkg{multicol} and while it ``should'' be transparent in other cases
+(and all tests in the regession test suite came out fine) there is the
+off-chance that code that hooked into internals of \pkg{multicol}
+needs adjustment.
+
+
+\section{Changes to packages in the amsmath category}
+
+With this release of \LaTeX{} a few minor issues with \pkg{amsmath}
+have been corrected.
+
+\subsection{Updated user's guide}
+
+Furthermore, \texttt{amsldoc.pdf}, the AMS user's
+guide for the \pkg{amsmath} package~\cite{amsldoc}, has been updated
+from version~2.0 to~2.1 to incorporate changes and corrections made
+between 2016 and 2018.
+
+
+\begin{thebibliography}{9}
+  
+\bibitem{Mittelbach:TB39-1} Frank Mittelbach:
+  \emph{New rules for reporting bugs in the \LaTeX{} core software}.  
+  In: TUGboat, 39\#1, 2018.
+  \url{https://www.latex-project.org/publications/}
+
+\bibitem{Mittelbach:Brno95} Frank Mittelbach:
+  \emph{\LaTeXe{} Encoding Interface --- Purpose, concepts, and 
+   Open Problems}.  
+  Talk given in Brno June 1995.
+  \url{https://www.latex-project.org/publications/}
+
+\bibitem{Mittelbach:TB39-2} Frank Mittelbach:
+  \emph{A rollback concept for packages and classes}.  
+  Submitted to TUGboat.
+  \url{https://www.latex-project.org/publications/}
+
+\bibitem{Mittelbach:TB38-2-213} Frank Mittelbach:
+  \emph{\LaTeX{} table columns with fixed widths}.  
+  In: TUGboat, 38\#2, 2017.
+  \url{https://www.latex-project.org/publications/}
+
+\bibitem{amsldoc} American Mathematical Society and The \LaTeX3 Project:
+  \emph{User's Guide for the \texttt{amsmath} package} (Version 2.1).  
+  April 2018.
+  Available from
+  \url{https://www.ctan.org}
+  and distributed as part of every \LaTeX{} distribution.
+
+\end{thebibliography}
+
+\end{document}
-- 
cgit v1.2.3

