Merge branch 'master' into harfbuzz

30 files changed, 567 insertions, 387 deletions

diff --git a/doc/emacs/arevert-xtra.texi b/doc/emacs/arevert-xtra.texi
index cd7c1ff895e..37e2f9e5818 100644
--- a/doc/emacs/arevert-xtra.texi
+++ b/doc/emacs/arevert-xtra.texi
@@ -4,8 +4,9 @@
 @c
 @c This file is included either in emacs-xtra.texi (when producing the
 @c printed version) or in the main Emacs manual (for the on-line version).
-@node Autorevert
-@section Auto Reverting Non-File Buffers
+
+@node Non-File Buffers
+@subsection Auto Reverting Non-File Buffers
 
 Global Auto Revert Mode normally only reverts file buffers.  There are
 two ways to auto-revert certain non-file buffers: by enabling Auto
@@ -34,6 +35,14 @@ the Buffer Menu.)  In this case, Auto Revert does not print any
 messages while reverting, even when @code{auto-revert-verbose} is
 non-@code{nil}.
 
+@vindex buffer-auto-revert-by-notification
+Some non-file buffers can be updated reliably by file notification on
+their default directory; Dired buffers is an example.  The major mode
+can indicate this by setting @code{buffer-auto-revert-by-notification}
+to a non-@code{nil} value in that buffer, allowing Auto Revert to
+avoid periodic polling.  Such notification does not include changes to
+files in that directory, only to the directory itself.
+
 The details depend on the particular types of buffers and are
 explained in the corresponding sections.
 
@@ -43,7 +52,7 @@ explained in the corresponding sections.
 @end menu
 
 @node Auto Reverting the Buffer Menu
-@subsection Auto Reverting the Buffer Menu
+@subsubsection Auto Reverting the Buffer Menu
 
 If auto-reverting of non-file buffers is enabled, the Buffer Menu
 @iftex
@@ -65,7 +74,7 @@ adding marks sets the buffer's modified flag prevents Auto Revert from
 automatically erasing the marks.
 
 @node Auto Reverting Dired
-@subsection Auto Reverting Dired buffers
+@subsubsection Auto Reverting Dired buffers
 
 Dired buffers only auto-revert when the file list of the buffer's main
 directory changes (e.g., when a new file is added or deleted).  They
diff --git a/doc/emacs/buffers.texi b/doc/emacs/buffers.texi
index 27fcb7369a9..14a0a01ca8b 100644
--- a/doc/emacs/buffers.texi
+++ b/doc/emacs/buffers.texi
@@ -568,10 +568,10 @@ mode in this buffer, as long as it is not marked modified.  Global
 Auto Revert mode applies to the @file{*Buffer List*} buffer only if
 @code{global-auto-revert-non-file-buffers} is non-@code{nil}.
 @iftex
-@inforef{Autorevert,, emacs-xtra}, for details.
+@inforef{Auto Reverting the Buffer Menu,, emacs-xtra}, for details.
 @end iftex
 @ifnottex
-@xref{Autorevert, global-auto-revert-non-file-buffers}, for details.
+@xref{Auto Reverting the Buffer Menu, global-auto-revert-non-file-buffers}, for details.
 @end ifnottex
 
 @node Indirect Buffers
diff --git a/doc/emacs/building.texi b/doc/emacs/building.texi
index 518d157e4ee..6e16588861e 100644
--- a/doc/emacs/building.texi
+++ b/doc/emacs/building.texi
@@ -1521,6 +1521,12 @@ library lets Emacs properly set up the hyperlinks in the @file{*Help*}
 buffer).  To disable this feature, change the variable
 @code{help-enable-auto-load} to @code{nil}.
 
+@vindex help-enable-completion-auto-load
+Automatic loading also occurs when completing names for
+@code{describe-variable} and @code{describe-function}, based on the
+prefix being completed.  To disable this feature, change the variable
+@code{help-enable-completion-auto-load} to @code{nil}.
+
 @vindex load-dangerous-libraries
 @cindex Lisp files byte-compiled by XEmacs
   By default, Emacs refuses to load compiled Lisp files which were
diff --git a/doc/emacs/cmdargs.texi b/doc/emacs/cmdargs.texi
index 00d5be70eb2..34a5ff5f2c1 100644
--- a/doc/emacs/cmdargs.texi
+++ b/doc/emacs/cmdargs.texi
@@ -39,7 +39,7 @@ corresponding long form.
 
   The long forms with @samp{--} are easier to remember, but longer to
 type.  However, you don't have to spell out the whole option name; any
-unambiguous abbreviation is enough.  When a long option takes an
+unambiguous abbreviation is enough.  When a long option requires an
 argument, you can use either a space or an equal sign to separate the
 option name and the argument.  Thus, for the option @samp{--display},
 you can write either @samp{--display sugar-bombs:0.0} or
@@ -347,13 +347,15 @@ Start Emacs with minimum customizations.  This is similar to using
 @itemx --bg-daemon[=@var{name}]
 @itemx --fg-daemon[=@var{name}]
 Start Emacs as a daemon: after Emacs starts up, it starts the Emacs
-server without opening any frames.
-(Optionally, you can specify an explicit @var{name} for the server.)
-You can then use the @command{emacsclient} command to connect to Emacs
-for editing.  @xref{Emacs Server}, for information about using Emacs
-as a daemon.  A ``background'' daemon disconnects from the terminal
-and runs in the background (@samp{--daemon} is an alias for
-@samp{--bg-daemon}).
+server without opening any frames.  You can then use the
+@command{emacsclient} command to connect to Emacs for editing.
+(Optionally, you can specify an explicit @var{name} for the server; if
+you do, you will need to specify the same @var{name} when you invoke
+@command{emacsclient}, via its @option{--socket-name} option, see
+@ref{emacsclient Options}.)  @xref{Emacs Server}, for information
+about using Emacs as a daemon.  A ``background'' daemon disconnects
+from the terminal and runs in the background (@samp{--daemon} is an
+alias for @samp{--bg-daemon}).
 
 @item --no-desktop
 @opindex --no-desktop
diff --git a/doc/emacs/custom.texi b/doc/emacs/custom.texi
index c649c170293..bdd6decb6b5 100644
--- a/doc/emacs/custom.texi
+++ b/doc/emacs/custom.texi
@@ -801,6 +801,7 @@ Its value is 70
   Automatically becomes buffer-local when set.
   This variable is safe as a file local variable if its value
   satisfies the predicate ‘integerp’.
+  Probably introduced at or before Emacs version 18.
 
 Documentation:
 Column beyond which automatic line-wrapping should happen.
@@ -1331,7 +1332,7 @@ On MS-DOS, the name of this file should be @file{_dir-locals.el}, due
 to limitations of the DOS filesystems.  If the filesystem is limited
 to 8+3 file names, the name of the file will be truncated by the OS to
 @file{_dir-loc.el}.
-}in a directory.  Whenever Emacs visits any file in that directory or
+} in a directory.  Whenever Emacs visits any file in that directory or
 any of its subdirectories, it will apply the directory-local variables
 specified in @file{.dir-locals.el}, as though they had been defined as
 file-local variables for that file (@pxref{File Variables}).  Emacs
@@ -1377,6 +1378,28 @@ be applied in the current directory, not in any subdirectories.
 Finally, it specifies a different @file{ChangeLog} file name for any
 file in the @file{src/imported} subdirectory.
 
+If the @file{.dir-locals.el} file contains multiple different values
+for a variable using different mode names or directories, the values
+will be applied in an order such that the values for more specific
+modes take priority over more generic modes.  Values specified under a
+directory have even more priority.  For example:
+
+@example
+((nil . ((fill-column . 40)))
+ (c-mode . ((fill-column . 50)))
+ (prog-mode . ((fill-column . 60)))
+ ("narrow-files" . ((nil . ((fill-column . 20))))))
+@end example
+
+Files that use @code{c-mode} also match @code{prog-mode} because the
+former inherits from the latter.  The value used for
+@code{fill-column} in C files will however be @code{50} because the
+mode name is more specific than @code{prog-mode}.  Files using other
+modes inheriting from @code{prog-mode} will use @code{60}.  Any file
+under the directory @file{narrow-files} will use the value @code{20}
+even if they use @code{c-mode} because directory entries have priority
+over mode entries.
+
 You can specify the variables @code{mode}, @code{eval}, and
 @code{unibyte} in your @file{.dir-locals.el}, and they have the same
 meanings as they would have in file local variables.  @code{coding}
diff --git a/doc/emacs/display.texi b/doc/emacs/display.texi
index f464a3a59f0..4985fabd541 100644
--- a/doc/emacs/display.texi
+++ b/doc/emacs/display.texi
@@ -1141,6 +1141,55 @@ right-to-left paragraphs.
 @node Displaying Boundaries
 @section Displaying Boundaries
 
+@cindex mode, display-fill-column-indicator
+@findex display-fill-column-indicator-mode
+@findex global-display-fill-column-indicator-mode
+  Emacs can add an indicator to display a fill column position.  The
+fill column indicator is a useful functionality specially in
+prog-mode to indicate the position of an specific column.
+
+  You can set the buffer-local variables @code{display-fill-column-indicator}
+and @code{display-fill-column-indicator-character} to activate the
+indicator and controls how the indicator looks.
+
+Alternatively you can type @w{@kbd{M-x display-fill-column-indicator-mode}}
+or @w{@kbd{M-x global-display-fill-column-indicator-mode}} which enables the
+indicator locally and globally respectively and also chooses the
+character to use if none is set already.  It is possible to use the
+first one to activate the indicator in a hook or the second one to
+enable it globally.
+
+There are 2 buffer local variables and 1 face to customize this mode:
+
+@table @code
+@item display-fill-column-indicator-column
+@vindex display-fill-column-indicator-column
+Specifies the column number where the indicator should be set.  It can
+take positive numerical values for the column or the special value
+@code{t} which means that the variable @code{fill-column} will be
+used.
+
+Any other value disables the indicator.  The default value is @code{t}.
+
+@item display-fill-column-indicator-char
+@vindex display-fill-column-indicator-char
+Specifies the character used for the indicator.  This character can be
+any valid char including unicode ones if the actual font supports
+them.
+
+When the mode is enabled through the functions
+@code{display-fill-column-indicator-mode} or
+@code{global-display-fill-column-indicator-mode}, the initialization
+functions check if this variable is @code{non-nil}, otherwise the
+initialization tries to set it to U+2502 or @samp{|}.
+
+@item fill-column-indicator
+@vindex fill-column-indicator
+Specifies the face used to display the indicator.  It inherits its
+default values from shadow but without background color.  To change
+the indicator color you need to set only the foreground color of this face.
+@end table
+
 @vindex indicate-buffer-boundaries
   On graphical displays, Emacs can indicate the buffer boundaries in
 the fringes.  If you enable this feature, the first line and the last
diff --git a/doc/emacs/emacs-xtra.texi b/doc/emacs/emacs-xtra.texi
index dcd8fae1b61..e9231b4e3a9 100644
--- a/doc/emacs/emacs-xtra.texi
+++ b/doc/emacs/emacs-xtra.texi
@@ -59,7 +59,7 @@ modify this GNU manual.''
 * Picture Mode::        Editing pictures made up of characters using
                          the quarter-plane screen model.
 
-* Autorevert::          Auto Reverting non-file buffers.
+* Non-File Buffers::    Auto Reverting non-file buffers.
 * Subdir Switches::     Subdirectory switches in Dired.
 * Advanced Calendar/Diary Usage:: Advanced Calendar/Diary customization.
 * Emerge::              A convenient way of merging two versions of a program.
diff --git a/doc/emacs/emacs.texi b/doc/emacs/emacs.texi
index 58ec3730299..a34cef221e1 100644
--- a/doc/emacs/emacs.texi
+++ b/doc/emacs/emacs.texi
@@ -443,9 +443,7 @@ File Handling
 * Visiting::            Visiting a file prepares Emacs to edit the file.
 * Saving::              Saving makes your changes permanent.
 * Reverting::           Reverting cancels all the changes not saved.
-@ifnottex
-* Autorevert::          Auto Reverting non-file buffers.
-@end ifnottex
+* Auto Revert::         Keeping buffers automatically up-to-date.
 * Auto Save::           Auto Save periodically protects against loss of data.
 * File Aliases::        Handling multiple names for one file.
 * Directories::         Creating, deleting, and listing file directories.
diff --git a/doc/emacs/files.texi b/doc/emacs/files.texi
index a57428230cc..36ef1dcea21 100644
--- a/doc/emacs/files.texi
+++ b/doc/emacs/files.texi
@@ -25,9 +25,7 @@ on file directories.
 * Visiting::            Visiting a file prepares Emacs to edit the file.
 * Saving::              Saving makes your changes permanent.
 * Reverting::           Reverting cancels all the changes not saved.
-@ifnottex
-* Autorevert::          Auto Reverting non-file buffers.
-@end ifnottex
+* Auto Revert::         Keeping buffers automatically up-to-date.
 * Auto Save::           Auto Save periodically protects against loss of data.
 * File Aliases::        Handling multiple names for one file.
 * Directories::         Creating, deleting, and listing file directories.
@@ -955,6 +953,11 @@ revert it automatically if it has changed---provided the buffer itself
 is not modified.  (If you have edited the text, it would be wrong to
 discard your changes.)
 
+  You can also tell Emacs to revert buffers automatically when their
+visited files change on disk; @pxref{Auto Revert}.
+
+@node Auto Revert
+@section Auto Revert: Keeping buffers automatically up-to-date
 @cindex Global Auto Revert mode
 @cindex mode, Global Auto Revert
 @cindex Auto Revert mode
@@ -962,22 +965,39 @@ discard your changes.)
 @findex global-auto-revert-mode
 @findex auto-revert-mode
 @findex auto-revert-tail-mode
-@vindex auto-revert-interval
-@vindex auto-revert-remote-files
+
+  A buffer can get out of sync with respect to its visited file on
+disk if that file is changed by another program.  To keep it up to
+date, you can enable Auto Revert mode by typing @kbd{M-x auto-revert-mode}.
+This automatically reverts the buffer when its visited file changes on
+disk.  To do the same for all file buffers, type
+@kbd{M-x global-auto-revert-mode} to enable Global Auto Revert mode.
+
+  Auto Revert will not revert a buffer if it has unsaved changes, or if
+its file on disk is deleted or renamed.
+
+  One use of Auto Revert mode is to ``tail'' a file such as a system
+log, so that changes made to that file by other programs are
+continuously displayed.  To do this, just move the point to the end of
+the buffer, and it will stay there as the file contents change.
+However, if you are sure that the file will only change by growing at
+the end, use Auto Revert Tail mode instead
+(@code{auto-revert-tail-mode}).  It is more efficient for this.
+Auto Revert Tail mode also works for remote files.
+
 @vindex auto-revert-verbose
-  You can also tell Emacs to revert buffers periodically.  To do this
-for a specific buffer, enable the minor mode Auto-Revert mode by
-typing @kbd{M-x auto-revert-mode}.  This automatically reverts the
-current buffer when its visited file changes on disk.  To do the same
-for all file buffers, type @kbd{M-x global-auto-revert-mode} to enable
-Global Auto-Revert mode.  These minor modes do not check or revert
-remote files, because that is usually too slow.  This behavior can be
-changed by setting the variable @code{auto-revert-remote-files} to
-non-@code{nil}.
+  When a buffer is auto-reverted, a message is generated.  This can be
+suppressed by setting @code{auto-revert-verbose} to @code{nil}.
+
+@vindex auto-revert-remote-files
+  The Auto Revert modes do not check or revert remote files, because
+that is usually too slow.  This behavior can be changed by setting the
+variable @code{auto-revert-remote-files} to non-@code{nil}.
 
 @cindex file notifications
 @vindex auto-revert-use-notify
-  By default, Auto-Revert mode works using @dfn{file notifications},
+@vindex auto-revert-interval
+  By default, Auto Revert mode works using @dfn{file notifications},
 whereby changes in the filesystem are reported to Emacs by the OS.
 You can disable use of file notifications by customizing the variable
 @code{auto-revert-use-notify} to a @code{nil} value, then Emacs will
@@ -988,19 +1008,22 @@ the polling interval through the variable @code{auto-revert-interval}.
 supported, @code{auto-revert-use-notify} will be @code{nil} by
 default.
 
-  One use of Auto-Revert mode is to ``tail'' a file such as a system
-log, so that changes made to that file by other programs are
-continuously displayed.  To do this, just move the point to the end of
-the buffer, and it will stay there as the file contents change.
-However, if you are sure that the file will only change by growing at
-the end, use Auto-Revert Tail mode instead
-(@code{auto-revert-tail-mode}).  It is more efficient for this.
-Auto-Revert Tail mode works also for remote files.
-
-  When a buffer is auto-reverted, a message is generated.  This can be
-suppressed by setting @code{auto-revert-verbose} to @code{nil}.
-
-  In Dired buffers (@pxref{Dired}), Auto-Revert mode refreshes the
+@vindex auto-revert-avoid-polling
+@vindex auto-revert-notify-exclude-dir-regexp
+  By default, Auto Revert mode will poll files for changes
+periodically even when file notifications are used.  Polling is
+unnecessary in many cases, and turning it off may save power by
+relying on notifications only.  To do so, set the variable
+@code{auto-revert-avoid-polling} to non-@code{nil}.  However,
+notification is ineffective on certain file systems; mainly network
+file system on Unix-like machines, where files can be altered from
+other machines.  For such file systems, polling may be necessary.
+To force polling when
+@code{auto-revert-avoid-polling} is non-@code{nil}, set
+@code{auto-revert-notify-exclude-dir-regexp} to match files that
+should be excluded from using notification.
+
+  In Dired buffers (@pxref{Dired}), Auto Revert mode refreshes the
 buffer when a file is created or deleted in the buffer's directory.
 
   @xref{VC Undo}, for commands to revert to earlier versions of files
@@ -1008,6 +1031,9 @@ under version control.  @xref{VC Mode Line}, for Auto Revert
 peculiarities when visiting files under version control.
 
 @ifnottex
+@menu
+* Non-File Buffers::    Auto Reverting Non-File Buffers.
+@end menu
 @include arevert-xtra.texi
 @end ifnottex
 
diff --git a/doc/emacs/maintaining.texi b/doc/emacs/maintaining.texi
index 4986c111030..0fbf91ae613 100644
--- a/doc/emacs/maintaining.texi
+++ b/doc/emacs/maintaining.texi
@@ -1033,6 +1033,7 @@ systems support modifying change comments.
 Visit the revision indicated at the current line.
 
 @item d
+@itemx =
 Display a diff between the revision at point and the next earlier
 revision, for the specific file.
 
@@ -1047,6 +1048,16 @@ L}), toggle between showing and hiding the full log entry for the
 revision at point.
 @end table
 
+To compare two arbitrary revisions, activate the region: set the
+beginning of the region to the line with the first revision and the
+end of the region to the line with the second revision to compare,
+then type @kbd{d} or @kbd{=}.  When the beginning of the region is on
+the top line that has no revision, it uses the current working revision
+as the first revision to compare.  When the end of the region is on
+the bottom non-revision line after the last revision line, then it
+uses the next earlier revision after the last displayed revision as
+the second revision to compare.
+
 @vindex vc-log-show-limit
 Because fetching many log entries can be slow, the
 @file{*vc-change-log*} buffer displays no more than 2000 revisions by
diff --git a/doc/emacs/misc.texi b/doc/emacs/misc.texi
index 7d7065a441a..cfc50d33b5f 100644
--- a/doc/emacs/misc.texi
+++ b/doc/emacs/misc.texi
@@ -775,6 +775,13 @@ documentation for more possibilities.
 displayed only when the command generates output, set
 @code{async-shell-command-display-buffer} to @code{nil}.
 
+@vindex async-shell-command-width
+  The option @code{async-shell-command-width} defines the number of display
+columns available for output of asynchronous shell commands.
+A positive integer tells the shell to use that number of columns for
+command output.  The default value is @code{nil} that means to use
+the same number of columns as provided by the shell.
+
 @kindex M-|
 @findex shell-command-on-region
   @kbd{M-|} (@code{shell-command-on-region}) is like @kbd{M-!}, but
@@ -1976,6 +1983,9 @@ omitted, @command{emacsclient} connects to the first server it finds.
 If you set @code{server-name} of the Emacs server to an absolute file
 name, give the same absolute file name as @var{server-name} to this
 option to instruct @command{emacsclient} to connect to that server.
+You need to use this option if you started Emacs as daemon
+(@pxref{Initial Options}) and specified the name for the server
+started by the daemon.
 
 Alternatively, you can set the @env{EMACS_SOCKET_NAME} environment
 variable to point to the server socket.  (The command-line option
@@ -2475,10 +2485,13 @@ automatically back to binary.
 into hex.  This is useful if you visit a file normally and then discover
 it is a binary file.
 
-  Ordinary text characters overwrite in Hexl mode.  This is to reduce
+  Inserting text always overwrites in Hexl mode.  This is to reduce
 the risk of accidentally spoiling the alignment of data in the file.
-There are special commands for insertion.  Here is a list of the
-commands of Hexl mode:
+Ordinary text characters insert themselves (i.e., overwrite with
+themselves).  There are commands for insertion of special characters
+by their code.  Most cursor motion keys, as well as @kbd{C-x C-s}, are
+bound in Hexl mode to commands that produce the same effect.  Here is
+a list of other important commands special to Hexl mode:
 
 @c I don't think individual index entries for these commands are useful--RMS.
 @table @kbd
@@ -2491,6 +2504,12 @@ Insert a byte with a code typed in octal.
 @item C-M-x
 Insert a byte with a code typed in hex.
 
+@item C-M-a
+Move to the beginning of a 512-byte page.
+
+@item C-M-e
+Move to the end of a 512-byte page.
+
 @item C-x [
 Move to the beginning of a 1k-byte page.
 
diff --git a/doc/emacs/programs.texi b/doc/emacs/programs.texi
index c1ad5b57023..28bfa5b578f 100644
--- a/doc/emacs/programs.texi
+++ b/doc/emacs/programs.texi
@@ -1298,8 +1298,11 @@ count as blocks.
 @findex hs-show-block
 @findex hs-show-region
 @findex hs-hide-level
+@findex hs-toggle-hiding
+@findex hs-mouse-toggle-hiding
 @kindex C-c @@ C-h
 @kindex C-c @@ C-s
+@kindex C-c @@ C-c
 @kindex C-c @@ C-M-h
 @kindex C-c @@ C-M-s
 @kindex C-c @@ C-r
@@ -1312,7 +1315,7 @@ Hide the current block (@code{hs-hide-block}).
 @item C-c @@ C-s
 Show the current block (@code{hs-show-block}).
 @item C-c @@ C-c
-@itemx C-x @@ C-e
+@itemx C-c @@ C-e
 Either hide or show the current block (@code{hs-toggle-hiding}).
 @item S-mouse-2
 Toggle hiding for the block you click on (@code{hs-mouse-toggle-hiding}).
diff --git a/doc/emacs/text.texi b/doc/emacs/text.texi
index 96492783b92..7892b346d2a 100644
--- a/doc/emacs/text.texi
+++ b/doc/emacs/text.texi
@@ -644,6 +644,10 @@ or before @samp{)}, @samp{:} or @samp{?}); and
 @code{fill-polish-nobreak-p} (don't break after a one letter word,
 even if preceded by a non-whitespace character).
 
+  Emacs can display an indicator in the @code{fill-column} position
+using the Display fill column indicator mode 
+(@pxref{Displaying Boundaries, display-fill-column-indicator}).
+
 @node Fill Prefix
 @subsection The Fill Prefix
 
diff --git a/doc/lispintro/emacs-lisp-intro.texi b/doc/lispintro/emacs-lisp-intro.texi
index 519decb1d04..46d86acd4c1 100644
--- a/doc/lispintro/emacs-lisp-intro.texi
+++ b/doc/lispintro/emacs-lisp-intro.texi
@@ -21858,14 +21858,17 @@ MENU ENTRY: NODE NAME.
 @end ifnottex
 
 @quotation
-Robert J. Chassell has worked with GNU Emacs since 1985.  He writes
-and edits, teaches Emacs and Emacs Lisp, and speaks throughout the
+Robert J. Chassell (1946--2017) started working with GNU Emacs in 1985.  He wrote
+and edited, taught Emacs and Emacs Lisp, and spoke throughout the
 world on software freedom.  Chassell was a founding Director and
-Treasurer of the Free Software Foundation, Inc.  He is co-author of
-the @cite{Texinfo} manual, and has edited more than a dozen other
-books.  He graduated from Cambridge University, in England.  He has an
-abiding interest in social and economic history and flies his own
+Treasurer of the Free Software Foundation, Inc.  He was co-author of
+the @cite{Texinfo} manual, and edited more than a dozen other
+books.  He graduated from Cambridge University, in England.  He had an
+abiding interest in social and economic history and flew his own
 airplane.
+
+@uref{https://www.fsf.org/blogs/community/goodbye-to-bob-chassell,
+"Goodbye to Bob Chassell"}
 @end quotation
 
 @c @page
diff --git a/doc/lispref/commands.texi b/doc/lispref/commands.texi
index cd44c1c87ef..5ea0be2667b 100644
--- a/doc/lispref/commands.texi
+++ b/doc/lispref/commands.texi
@@ -1047,12 +1047,9 @@ and meaning of input events in detail.
 This function returns non-@code{nil} if @var{object} is an input event
 or event type.
 
-Note that any symbol might be used as an event or an event type.
-@code{eventp} cannot distinguish whether a symbol is intended by Lisp
-code to be used as an event.  Instead, it distinguishes whether the
-symbol has actually been used in an event that has been read as input in
-the current Emacs session.  If a symbol has not yet been so used,
-@code{eventp} returns @code{nil}.
+Note that any non-@code{nil} symbol might be used as an event or an
+event type; @code{eventp} cannot distinguish whether a symbol is
+intended by Lisp code to be used as an event.
 @end defun
 
 @menu
diff --git a/doc/lispref/hooks.texi b/doc/lispref/hooks.texi
index 71992464e09..f775aa4d4b0 100644
--- a/doc/lispref/hooks.texi
+++ b/doc/lispref/hooks.texi
@@ -251,6 +251,7 @@ I thought did not need to be mentioned here:
 
 Lisp:
 after-load-functions
+after-set-visited-file-name-hook
 auto-coding-functions
 choose-completion-string-functions
 completing-read-function
diff --git a/doc/lispref/internals.texi b/doc/lispref/internals.texi
index 5ae71afbef2..cfeb492af40 100644
--- a/doc/lispref/internals.texi
+++ b/doc/lispref/internals.texi
@@ -1191,6 +1191,17 @@ grow with new Emacs releases.  Given the version of Emacs, the module
 can use only the parts of the module @acronym{API} that existed in
 that version, since those parts are identical in later versions.
 
+@file{emacs-module.h} defines a preprocessor macro
+@code{EMACS_MAJOR_VERSION}.  It expands to an integer literal which is
+the latest major version of Emacs supported by the header.
+@xref{Version Info}.  Note that the value of
+@code{EMACS_MAJOR_VERSION} is a compile-time constant and does not
+represent the version of Emacs that is currently running and has
+loaded your module.  If you want your module to be compatible with
+various versions of @file{emacs-module.h} as well as various versions
+of Emacs, you can use conditional compilation based on
+@code{EMACS_MAJOR_VERSION}.
+
 We recommend that modules always perform the compatibility
 verification, unless they do their job entirely in the initialization
 function, and don't access any Lisp objects or use any Emacs functions
diff --git a/doc/lispref/loading.texi b/doc/lispref/loading.texi
index 6f1213f097b..3261e6d1888 100644
--- a/doc/lispref/loading.texi
+++ b/doc/lispref/loading.texi
@@ -466,9 +466,11 @@ first call to the function automatically loads the proper library, in
 order to install the real definition and other associated code, then
 runs the real definition as if it had been loaded all along.
 Autoloading can also be triggered by looking up the documentation of
-the function or macro (@pxref{Documentation Basics}).
+the function or macro (@pxref{Documentation Basics}), and completion
+of variable and function names (@pxref{Autoload by Prefix} below).
 
 @menu
+* Autoload by Prefix:: Autoload by Prefix.
 * When to Autoload::   When to Use Autoload.
 @end menu
 
@@ -703,6 +705,25 @@ symbol's new function value.  If the value of the optional argument
 function, only a macro.
 @end defun
 
+@node Autoload by Prefix
+@subsection Autoload by Prefix
+@cindex autoload by prefix
+
+@vindex definition-prefixes
+@findex register-definition-prefixes
+@vindex autoload-compute-prefixes
+During completion for the commands @code{describe-variable} and
+@code{describe-function}, Emacs will try to load files which may
+contain definitions matching the prefix being completed.  The variable
+@code{definition-prefixes} holds a hashtable which maps a prefix to
+the corresponding list of files to load for it.  Entries to this
+mapping are added by calls to @code{register-definition-prefixes}
+which are generated by @code{update-file-autoloads}
+(@pxref{Autoload}).  Files which don't contain any definitions worth
+loading (test files, for examples), should set
+@code{autoload-compute-prefixes} to @code{nil} as a file-local
+variable.
+
 @node When to Autoload
 @subsection When to Use Autoload
 @cindex autoload, when to use
diff --git a/doc/lispref/modes.texi b/doc/lispref/modes.texi
index 4315b70ed72..97e9be9918f 100644
--- a/doc/lispref/modes.texi
+++ b/doc/lispref/modes.texi
@@ -3238,7 +3238,12 @@ is disabled, @code{font-lock-face} has no effect on the display.
   It is ok for a mode to use @code{font-lock-face} for some text and
 also use the normal Font Lock machinery.  But if the mode does not use
 the normal Font Lock machinery, it should not set the variable
-@code{font-lock-defaults}.
+@code{font-lock-defaults}.  In this case the @code{face} property will
+not be overriden, so using the @code{face} property could work too.
+However, using @code{font-lock-face} is generally preferable as it
+allows the user to control the fontification by toggling
+@code{font-lock-mode}, and lets the code work regardless of whether
+the mode uses Font Lock machinery or not.
 
 @node Faces for Font Lock
 @subsection Faces for Font Lock
diff --git a/doc/lispref/nonascii.texi b/doc/lispref/nonascii.texi
index 9c64c3cf2ca..47206a406fd 100644
--- a/doc/lispref/nonascii.texi
+++ b/doc/lispref/nonascii.texi
@@ -1049,7 +1049,7 @@ is like @code{undecided}, but it prefers to choose @code{utf-8} when
 possible.
 
   In general, a coding system doesn't guarantee roundtrip identity:
-decoding a byte sequence using coding system, then encoding the
+decoding a byte sequence using a coding system, then encoding the
 resulting text in the same coding system, can produce a different byte
 sequence.  But some coding systems do guarantee that the byte sequence
 will be the same as what you originally decoded.  Here are a few
diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index 59cd5a8fe8a..fef954eb7a3 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -2197,7 +2197,7 @@ is the character Emacs currently uses for quitting, usually @kbd{C-g}.
 @subsection Recording Input
 @cindex recording input
 
-@defun recent-keys
+@defun recent-keys &optional include-cmds
 This function returns a vector containing the last 300 input events from
 the keyboard or mouse.  All input events are included, whether or not
 they were used as parts of key sequences.  Thus, you always get the last
@@ -2205,6 +2205,11 @@ they were used as parts of key sequences.  Thus, you always get the last
 (These are excluded because they are less interesting for debugging; it
 should be enough to see the events that invoked the macros.)
 
+If @var{include-cmds} is non-@code{nil}, complete key sequences in the
+result vector are interleaved with pseudo-events of the form
+@code{(nil . @var{COMMAND})}, where @var{COMMAND} is the binding of
+the key sequence (@pxref{Command Overview}).
+
 A call to @code{clear-this-command-keys} (@pxref{Command Loop Info})
 causes this function to return an empty vector immediately afterward.
 @end defun
diff --git a/doc/lispref/processes.texi b/doc/lispref/processes.texi
index 69f781e3a9f..b73401a62a2 100644
--- a/doc/lispref/processes.texi
+++ b/doc/lispref/processes.texi
@@ -1688,7 +1688,7 @@ how to do these things:
         (save-excursion
           ;; @r{Insert the text, advancing the process marker.}
           (goto-char (process-mark proc))
-          (insert string)
+          (insert-before-markers string)
           (set-marker (process-mark proc) (point)))
         (if moving (goto-char (process-mark proc)))))))
 @end group
diff --git a/doc/lispref/searching.texi b/doc/lispref/searching.texi
index 8775254dd07..24f30b4dac6 100644
--- a/doc/lispref/searching.texi
+++ b/doc/lispref/searching.texi
@@ -1070,6 +1070,13 @@ list of characters @var{chars}.
 
 @c Internal functions: regexp-opt-group
 
+@defvar regexp-unmatchable
+This variable contains a regexp that is guaranteed not to match any
+string at all.  It is particularly useful as default value for
+variables that may be set to a pattern that actually matches
+something.
+@end defvar
+
 @node Regexp Search
 @section Regular Expression Searching
 @cindex regular expression searching
diff --git a/doc/lispref/sequences.texi b/doc/lispref/sequences.texi
index a7f270c0680..4b67a5f9f1a 100644
--- a/doc/lispref/sequences.texi
+++ b/doc/lispref/sequences.texi
@@ -601,7 +601,7 @@ returned value is a list.
 @defun seq-mapn function &rest sequences
   This function returns the result of applying @var{function} to each
 element of @var{sequences}.  The arity (@pxref{What Is a Function,
-sub-arity}) of @var{function} must match the number of sequences.
+subr-arity}) of @var{function} must match the number of sequences.
 Mapping stops at the end of the shortest sequence, and the returned
 value is a list.
 
diff --git a/doc/lispref/text.texi b/doc/lispref/text.texi
index 500df1f8f0d..278bc3c2680 100644
--- a/doc/lispref/text.texi
+++ b/doc/lispref/text.texi
@@ -2252,9 +2252,11 @@ If it is impossible to move to column @var{column} because that is in
 the middle of a multicolumn character such as a tab, point moves to the
 end of that character.  However, if @var{force} is non-@code{nil}, and
 @var{column} is in the middle of a tab, then @code{move-to-column}
-converts the tab into spaces so that it can move precisely to column
-@var{column}.  Other multicolumn characters can cause anomalies despite
-@var{force}, since there is no way to split them.
+either converts the tab into spaces (when @code{indent-tabs-mode} is
+@code{nil}), or inserts enough spaces before it (otherwise), so that
+point can move precisely to column @var{column}.  Other multicolumn
+characters can cause anomalies despite @var{force}, since there is no
+way to split them.
 
 The argument @var{force} also has an effect if the line isn't long
 enough to reach column @var{column}; if it is @code{t}, that means to
diff --git a/doc/lispref/variables.texi b/doc/lispref/variables.texi
index aca7d2f5e93..932b7c829b9 100644
--- a/doc/lispref/variables.texi
+++ b/doc/lispref/variables.texi
@@ -2009,7 +2009,7 @@ all files in those directories.  The list in @var{variables} can be of
 one of the two forms: @code{(@var{major-mode} . @var{alist})} or
 @code{(@var{directory} . @var{list})}.  With the first form, if the
 file's buffer turns on a mode that is derived from @var{major-mode},
-then the all the variables in the associated @var{alist} are applied;
+then all the variables in the associated @var{alist} are applied;
 @var{alist} should be of the form @code{(@var{name} . @var{value})}.
 A special value @code{nil} for @var{major-mode} means the settings are
 applicable to any mode.  In @var{alist}, you can use a special
diff --git a/doc/lispref/windows.texi b/doc/lispref/windows.texi
index 32e8c2afa31..96e42a148c5 100644
--- a/doc/lispref/windows.texi
+++ b/doc/lispref/windows.texi
@@ -2601,6 +2601,63 @@ window and displaying the buffer in that window.  It can fail if all
 windows are dedicated to other buffers (@pxref{Dedicated Windows}).
 @end defun
 
+@defun display-buffer-in-direction buffer alist
+This function tries to display @var{buffer} at a location specified by
+@var{alist}.  For this purpose, @var{alist} should contain a
+@code{direction} entry whose value is one of @code{left}, @code{above}
+(or @code{up}), @code{right} and @code{below} (or @code{down}).  Other
+values are usually interpreted as @code{below}.
+
+If @var{alist} also contains a @code{window} entry, its value
+specifies a reference window.  That value can be a special symbol like
+@code{main} which stands for the selected frame's main window
+(@pxref{Side Window Options and Functions}) or @code{root} standing
+for the selected frame's root window (@pxref{Windows and Frames}).  It
+can also specify an arbitrary valid window.  Any other value (or
+omitting the @code{window} entry entirely) means to use the selected
+window as reference window.
+
+This function first tries to reuse a window in the specified direction
+that already shows @var{buffer}.  If no such window exists, it tries
+to split the reference window in order to produce a new window in the
+specified direction.  If this fails as well, it will try to display
+@var{buffer} in an existing window in the specified direction.  In
+either case, the window chosen will appear on the side of the
+reference window specified by the @code{direction} entry, sharing at
+least one edge with the reference window.
+
+If the reference window is live, the edge the chosen window will share
+with it is always the opposite of the one specified by the
+@code{direction} entry.  For example, if the value of the
+@code{direction} entry is @code{left}, the chosen window's right edge
+coordinate (@pxref{Coordinates and Windows}) will equal the reference
+window's left edge coordinate.
+
+If the reference window is internal, a reused window must share with
+it the edge specified by the @code{direction} entry.  Hence if, for
+example, the reference window is the frame's root window and the value
+of the @code{direction} entry is @code{left}, a reused window must be
+on the left of the frame.  This means that the left edge coordinate of
+the chosen window and that of the reference window are the same.
+
+A new window, however, will be created by splitting the reference
+window such that the chosen window will share the opposite edge with
+the reference window.  In our example, a new root window would be
+created with a new live window and the reference window as its
+children.  The chosen window's right edge coordinate would then equal
+the left edge coordinate of the reference window.  Its left edge
+coordinate would equal the left edge coordinate of the frame's new
+root window.
+
+Four special values for @code{direction} entries allow to implicitly
+specify the selected frame's main window as the reference window:
+@code{leftmost}, @code{top}, @code{rightmost} and @code{bottom}.  This
+means that instead of, for example, @w{@code{(direction . left)
+(window . main)}} one can just specify @w{@code{(direction
+. leftmost)}}.  An existing @code{window} @var{alist} entry is ignored
+in such cases.
+@end defun
+
 @defun display-buffer-below-selected buffer alist
 This function tries to display @var{buffer} in a window below the
 selected window.  If there is a window below the selected one and that
@@ -2934,12 +2991,20 @@ If non-@code{nil}, the value specifies the slot of the side window
 supposed to display the buffer.  This entry is used only by
 @code{display-buffer-in-side-window}.
 
+@vindex direction@r{, a buffer display action alist entry}
+@item direction
+The value specifies a direction which, together with a @code{window}
+entry, allows @code{display-buffer-in-direction} to determine the
+location of the window to display the buffer.
+
 @vindex window@r{, a buffer display action alist entry}
 @item window
 The value specifies a window that is in some way related to the window
 chosen by @code{display-buffer}.  This entry is currently used by
 @code{display-buffer-in-atom-window} to indicate the window on whose
-side the new window shall be created.
+side the new window shall be created.  It is also used by
+@code{display-buffer-in-direction} to specify the reference window on
+whose side the resulting window shall appear.
 
 @vindex allow-no-window@r{, a buffer display action alist entry}
 @item allow-no-window
diff --git a/doc/misc/flymake.texi b/doc/misc/flymake.texi
index 894203ca5a1..ebb89c32036 100644
--- a/doc/misc/flymake.texi
+++ b/doc/misc/flymake.texi
@@ -88,10 +88,6 @@ the buffer is saved, unless @code{flymake-start-on-save-buffer} is
 nil;
 
 @item
-a newline character is added to the buffer, unless
-@code{flymake-start-syntax-check-on-newline} is nil;
-
-@item
 some changes were made to the buffer more than @code{0.5} seconds ago
 (the delay is configurable in @code{flymake-no-changes-timeout}).
 @end itemize
@@ -222,10 +218,6 @@ If any changes are made to the buffer, syntax check is automatically
 started after this many seconds, unless the user makes another change,
 which resets the timer.
 
-@item flymake-start-syntax-check-on-newline
-A boolean flag indicating whether to start syntax check immediately
-after a newline character is inserted into the buffer.
-
 @item flymake-start-on-flymake-mode
 A boolean flag indicating whether to start syntax check immediately
 after enabling @code{flymake-mode}.
diff --git a/doc/misc/texinfo.tex b/doc/misc/texinfo.tex
index 192284cccc1..ccd112941ac 100644
--- a/doc/misc/texinfo.tex
+++ b/doc/misc/texinfo.tex
@@ -3,8 +3,7 @@
 % Load plain if necessary, i.e., if running under initex.
 \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
 %
-\def\texinfoversion{2019-03-03.15}
-
+\def\texinfoversion{2019-04-12.13}
 %
 % Copyright 1985, 1986, 1988, 1990-2019 Free Software Foundation, Inc.
 %
@@ -387,14 +386,8 @@
     % take effect in \write's, yet the group defined by the \vbox ends
     % before the \shipout runs.
     %
-    \indexdummies         % don't expand commands in the output.
-    \normalturnoffactive  % \ in index entries must not stay \, e.g., if
-               % the page break happens to be in the middle of an example.
-               % We don't want .vr (or whatever) entries like this:
-               % \entry{{\indexbackslash }acronym}{32}{\code {\acronym}}
-               % "\acronym" won't work when it's read back in;
-               % it needs to be
-               % {\code {{\backslashcurfont }acronym}
+    \atdummies         % don't expand commands in the output.
+    \turnoffactive
     \shipout\vbox{%
       % Do this early so pdf references go to the beginning of the page.
       \ifpdfmakepagedest \pdfdest name{\the\pageno} xyz\fi
@@ -455,11 +448,10 @@
   }%
 }
 
-% First remove any @comment, then any @c comment.  Also remove a @texinfoc
-% comment (see \scanmacro for details).  Pass the result on to \argcheckspaces.
+% First remove any @comment, then any @c comment.  Pass the result on to 
+% \argcheckspaces.
 \def\argremovecomment#1\comment#2\ArgTerm{\argremovec #1\c\ArgTerm}
-\def\argremovec#1\c#2\ArgTerm{\argremovetexinfoc #1\texinfoc\ArgTerm}
-\def\argremovetexinfoc#1\texinfoc#2\ArgTerm{\argcheckspaces#1\^^M\ArgTerm}
+\def\argremovec#1\c#2\ArgTerm{\argcheckspaces#1\^^M\ArgTerm}
 
 % Each occurrence of `\^^M' or `<space>\^^M' is replaced by a single space.
 %
@@ -1131,6 +1123,16 @@ where each line of input produces a line of output.}
   \fi
 \fi
 
+\newif\ifpdforxetex
+\pdforxetexfalse
+\ifpdf
+  \pdforxetextrue
+\fi
+\ifx\XeTeXrevision\thisisundefined\else
+  \pdforxetextrue
+\fi
+
+
 % PDF uses PostScript string constants for the names of xref targets,
 % for display in the outlines, and in other places.  Thus, we have to
 % double any backslashes.  Otherwise, a name like "\node" will be
@@ -2173,7 +2175,7 @@ end
 % A few fonts for @defun names and args.
 \setfont\defbf\bfshape{10}{\magstep1}{OT1}
 \setfont\deftt\ttshape{10}{\magstep1}{OT1TT}
-\setfont\defsl\slshape{10}{\magstep1}{OT1TT}
+\setfont\defsl\slshape{10}{\magstep1}{OT1}
 \setfont\defttsl\ttslshape{10}{\magstep1}{OT1TT}
 \def\df{\let\ttfont=\deftt \let\bffont = \defbf
 \let\ttslfont=\defttsl \let\slfont=\defsl \bf}
@@ -2321,7 +2323,7 @@ end
 % A few fonts for @defun names and args.
 \setfont\defbf\bfshape{10}{\magstephalf}{OT1}
 \setfont\deftt\ttshape{10}{\magstephalf}{OT1TT}
-\setfont\defsl\slshape{10}{\magstephalf}{OT1TT}
+\setfont\defsl\slshape{10}{\magstephalf}{OT1}
 \setfont\defttsl\ttslshape{10}{\magstephalf}{OT1TT}
 \def\df{\let\ttfont=\deftt \let\bffont = \defbf
 \let\slfont=\defsl \let\ttslfont=\defttsl \bf}
@@ -2844,7 +2846,7 @@ end
 
 % @t, explicit typewriter.
 \def\t#1{%
-  {\tt \rawbackslash \plainfrenchspacing #1}%
+  {\tt \plainfrenchspacing #1}%
   \null
 }
 
@@ -2871,7 +2873,6 @@ end
     % Turn off hyphenation.
     \nohyphenation
     %
-    \rawbackslash
     \plainfrenchspacing
     #1%
   }%
@@ -3097,9 +3098,9 @@ end
 % Allow a ragged right output to aid breaking long URL's.  Putting stretch in 
 % between characters of the URL doesn't look good.
 \def\urefallowbreak{%
-  \hskip 0pt plus 1fil\relax
+  \hskip 0pt plus 4 em\relax
   \allowbreak
-  \hskip 0pt plus -1fil\relax
+  \hskip 0pt plus -4 em\relax
 }
 
 \urefbreakstyle after
@@ -3112,7 +3113,7 @@ end
 % So now @email is just like @uref, unless we are pdf.
 %
 %\def\email#1{\angleleft{\tt #1}\angleright}
-\ifpdf
+\ifpdforxetex
   \def\email#1{\doemail#1,,\finish}
   \def\doemail#1,#2,#3\finish{\begingroup
     \unsepspaces
@@ -3122,18 +3123,7 @@ end
     \endlink
   \endgroup}
 \else
-  \ifx\XeTeXrevision\thisisundefined
-    \let\email=\uref
-  \else
-    \def\email#1{\doemail#1,,\finish}
-    \def\doemail#1,#2,#3\finish{\begingroup
-      \unsepspaces
-      \pdfurl{mailto:#1}%
-      \setbox0 = \hbox{\ignorespaces #2}%
-      \ifdim\wd0>0pt\unhbox0\else\code{#1}\fi
-      \endlink
-    \endgroup}
-  \fi
+  \let\email=\uref
 \fi
 
 % @kbdinputstyle -- arg is `distinct' (@kbd uses slanted tty font always),
@@ -4667,19 +4657,6 @@ end
   }
 }
 
-% We have this subroutine so that we can handle at least some @value's
-% properly in indexes (we call \makevalueexpandable in \indexdummies).
-% The command has to be fully expandable (if the variable is set), since
-% the result winds up in the index file.  This means that if the
-% variable's value contains other Texinfo commands, it's almost certain
-% it will fail (although perhaps we could fix that with sufficient work
-% to do a one-level expansion on the result, instead of complete).
-% 
-% Unfortunately, this has the consequence that when _ is in the *value*
-% of an @set, it does not print properly in the roman fonts (get the cmr
-% dot accent at position 126 instead).  No fix comes to mind, and it's
-% been this way since 2003 or earlier, so just ignore it.
-% 
 \def\expandablevalue#1{%
   \expandafter\ifx\csname SET#1\endcsname\relax
     {[No value for ``#1'']}%
@@ -4708,7 +4685,7 @@ end
 % if possible, otherwise sort late.
 \def\indexnofontsvalue#1{%
   \expandafter\ifx\csname SET#1\endcsname\relax
-    ZZZZZZZ
+    ZZZZZZZ%
   \else
     \csname SET#1\endcsname
   \fi
@@ -4858,23 +4835,8 @@ end
 \def\docodeindexxxx #1{\doind{\indexname}{\code{#1}}}
 
 
-% Used when writing an index entry out to an index file to prevent
-% expansion of Texinfo commands that can appear in an index entry.
-%
-\def\indexdummies{%
-  \escapechar = `\\     % use backslash in output files.
-  \definedummyletter\@%
-  \definedummyletter\ %
-  %
-  % For texindex which always views { and } as separators.
-  \def\{{\lbracechar{}}%
-  \def\}{\rbracechar{}}%
-  %
-  % Do the redefinitions.
-  \definedummies
-}
-
-% Used for the aux and toc files, where @ is the escape character.
+% Used for the aux, toc and index files to prevent expansion of Texinfo 
+% commands.
 %
 \def\atdummies{%
   \definedummyletter\@%
@@ -4904,8 +4866,7 @@ end
 \def\definedummyletter#1{\def#1{\string#1}}%
 \let\definedummyaccent\definedummyletter
 
-% Called from \indexdummies and \atdummies, to effectively prevent
-% the expansion of commands.
+% Called from \atdummies to prevent the expansion of commands.
 %
 \def\definedummies{%
   %
@@ -4954,6 +4915,7 @@ end
   % Assorted special characters.
   \definedummyword\atchar
   \definedummyword\arrow
+  \definedummyword\backslashchar
   \definedummyword\bullet
   \definedummyword\comma
   \definedummyword\copyright
@@ -5070,11 +5032,10 @@ end
   \commondummyword\xref
 }
 
-% This does nothing, but for a time it was recommended to use
-% \usebracesinindexestrue to be able to use braces in index entries.
-
 \let\indexlbrace\relax
 \let\indexrbrace\relax
+\let\indexatchar\relax
+\let\indexbackslash\relax
 
 {\catcode`\@=0
 \catcode`\\=13
@@ -5108,10 +5069,8 @@ end
   }
 
   \gdef\indexnonalnumreappear{%
-    \useindexbackslash
     \let-\normaldash
     \let<\normalless
-    \def\@{@}%
   }
 }
 
@@ -5222,8 +5181,6 @@ end
 
 
 
-\let\SETmarginindex=\relax % put index entries in margin (undocumented)?
-
 % #1 is the index name, #2 is the entry text.
 \def\doind#1#2{%
   \iflinks
@@ -5255,13 +5212,6 @@ end
 \fi}
 \def\indexisfl{fl}
 
-% Output \ as {\indexbackslash}, because \ is an escape character in
-% the index files.
-\let\indexbackslash=\relax
-{\catcode`\@=0 \catcode`\\=\active
-  @gdef@useindexbackslash{@def\{{@indexbackslash}}}
-}
-
 % Definition for writing index entry sort key.
 {
 \catcode`\-=13
@@ -5273,14 +5223,31 @@ end
   \xdef\indexsortkey{#1}\endgroup}
 }
 
+\def\indexwriteseealso#1{
+  \gdef\pagenumbertext{@seealso{#1}}%
+}
+\def\indexwriteseeentry#1{
+  \gdef\pagenumbertext{@seeentry{#1}}%
+}
+
+% The default definitions
+\def\sortas#1{}%
+\def\seealso#1{\i{\putwordSeeAlso}\ #1}% for sorted index file only
+\def\putwordSeeAlso{See also}
+\def\seeentry#1{\i{\putwordSee}\ #1}% for sorted index file only
+
+
 % Given index entry text like "aaa @subentry bbb @sortas{ZZZ}":
 %   * Set \bracedtext to "{aaa}{bbb}"
 %   * Set \fullindexsortkey to "aaa @subentry ZZZ"
+%   * If @seealso occurs, set \pagenumbertext
 %
 \def\splitindexentry#1{%
   \gdef\fullindexsortkey{}%
   \xdef\bracedtext{}%
   \def\sep{}%
+  \def\seealso##1{}%
+  \def\seeentry##1{}%
   \expandafter\doindexsegment#1\subentry\finish\subentry
 }
 
@@ -5292,7 +5259,6 @@ end
     %
     % Fully expand the segment, throwing away any @sortas directives, and 
     % trim spaces.
-    \def\sortas##1{}%
     \edef\trimmed{\segment}%
     \edef\trimmed{\expandafter\eatspaces\expandafter{\trimmed}}%
     %
@@ -5302,16 +5268,23 @@ end
     % font commands turned off.
     \bgroup
       \let\sortas\indexwritesortas
+      \let\seealso\indexwriteseealso
+      \let\seeentry\indexwriteseeentry
       \indexnofonts
       % The braces around the commands are recognized by texindex.
-      \def\lbracechar{{\indexlbrace}}%
-      \def\rbracechar{{\indexrbrace}}%
+      \def\lbracechar{{\string\indexlbrace}}%
+      \def\rbracechar{{\string\indexrbrace}}%
       \let\{=\lbracechar
       \let\}=\rbracechar
+      \def\@{{\string\indexatchar}}%
+      \def\atchar##1{\@}%
+      \def\backslashchar{{\string\indexbackslash}}%
+      \uccode`\~=`\\ \uppercase{\let~\backslashchar}%
       %
       \let\indexsortkey\empty
+      \global\let\pagenumbertext\empty
       % Execute the segment and throw away the typeset output.  This executes
-      % any @sortas commands in this segment.
+      % any @sortas or @seealso commands in this segment.
       \setbox\dummybox = \hbox{\segment}%
       \ifx\indexsortkey\empty{%
         \indexnonalnumdisappear
@@ -5332,21 +5305,31 @@ end
   \fi
 }
 \def\isfinish{\finish}%
+\newbox\dummybox % used above
 
 \let\subentry\relax
 
-% Write the entry in \toks0 to the index file.
+% Use \ instead of @ in index files.  To support old texi2dvi and texindex.
+% This works without changing the escape character used in the toc or aux
+% files because the index entries are fully expanded here, and \string uses
+% the current value of \escapechar.
+\def\escapeisbackslash{\escapechar=`\\}
+
+% Write the entry in \indextext to the index file.
 %
 \def\doindwrite{%
-  % Put the index entry in the margin if desired.
-  \ifx\SETmarginindex\relax\else
-    \insert\margin{\hbox{\vrule height8pt depth3pt width0pt \the\toks0}}%
+  \maybemarginindex
+  %
+  \atdummies
+  %
+  \expandafter\ifx\csname SETtxiindexescapeisbackslash\endcsname\relax\else
+    \escapeisbackslash
   \fi
   %
-  % Remember, we are within a group.
-  \indexdummies % Must do this here, since \bf, etc expand at this stage
-  \useindexbackslash % \indexbackslash isn't defined now so it will be output 
-                     % as is; and it will print as backslash.
+  % For texindex which always views { and } as separators.
+  \def\{{\lbracechar{}}%
+  \def\}{\rbracechar{}}%
+  \uccode`\~=`\\ \uppercase{\def~{\backslashchar{}}}%
   %
   % Split the entry into primary entry and any subentries, and get the index 
   % sort key.
@@ -5360,11 +5343,21 @@ end
   %
   \edef\temp{%
     \write\writeto{%
-      \string\entry{\fullindexsortkey}{\noexpand\folio}\bracedtext}%
+      \string\entry{\fullindexsortkey}%
+        {\ifx\pagenumbertext\empty\noexpand\folio\else\pagenumbertext\fi}%
+        \bracedtext}%
   }%
   \temp
 }
-\newbox\dummybox % used above
+
+% Put the index entry in the margin if desired (undocumented).
+\def\maybemarginindex{%
+  \ifx\SETmarginindex\relax\else
+    \insert\margin{\hbox{\vrule height8pt depth3pt width0pt \relax\indextext}}%
+  \fi
+}
+\let\SETmarginindex=\relax
+
 
 % Take care of unwanted page breaks/skips around a whatsit:
 %
@@ -5452,9 +5445,14 @@ end
 %  \entry {topic}{pagelist}
 %     for a topic that is used without subtopics
 %  \primary {topic}
+%  \entry {topic}{}
 %     for the beginning of a topic that is used with subtopics
 %  \secondary {subtopic}{pagelist}
 %     for each subtopic.
+%  \secondary {subtopic}{}
+%     for a subtopic with sub-subtopics
+%  \tertiary {subtopic}{subsubtopic}{pagelist}
+%     for each sub-subtopic.
 
 % Define the user-accessible indexing commands
 % @findex, @vindex, @kindex, @cindex.
@@ -5479,14 +5477,10 @@ end
   \plainfrenchspacing
   \everypar = {}% don't want the \kern\-parindent from indentation suppression.
   %
-  % See if the index file exists and is nonempty.
-  % Change catcode of @ here so that if the index file contains
-  % \initial {@}
-  % as its first line, TeX doesn't complain about mismatched braces
-  % (because it thinks @} is a control sequence).
-  \catcode`\@ = 12
   % See comment in \requireopenindexfile.
   \def\indexname{#1}\ifx\indexname\indexisfl\def\indexname{f1}\fi
+  %
+  % See if the index file exists and is nonempty.
   \openin 1 \jobname.\indexname s
   \ifeof 1
     % \enddoublecolumns gets confused if there is no text in the index,
@@ -5496,8 +5490,6 @@ end
     \putwordIndexNonexistent
     \typeout{No file \jobname.\indexname s.}%
   \else
-    \catcode`\\ = 0
-    %
     % If the index file exists but is empty, then \openin leaves \ifeof
     % false.  We have to make TeX try to read something from the file, so
     % it can discover if there is anything in it.
@@ -5505,47 +5497,52 @@ end
     \ifeof 1
       \putwordIndexIsEmpty
     \else
-      % Index files are almost Texinfo source, but we use \ as the escape
-      % character.  It would be better to use @, but that's too big a change
-      % to make right now.
-      \def\indexbackslash{\ttbackslash}%
-      \let\indexlbrace\{   % Likewise, set these sequences for braces
-      \let\indexrbrace\}   % used in the sort key.
-      \begindoublecolumns
-      \let\dotheinsertentrybox\dotheinsertentryboxwithpenalty
-      %
-      % Read input from the index file line by line.
-      \loopdo
-        \ifeof1 \else
-          \read 1 to \nextline
-        \fi
-        %
-        \indexinputprocessing
-        \thisline
-        %
-        \ifeof1\else
-        \let\thisline\nextline
-      \repeat
-      %%
-      \enddoublecolumns
+      \expandafter\printindexzz\thisline\relax\relax\finish%
     \fi
   \fi
   \closein 1
 \endgroup}
-\def\loopdo#1\repeat{\def\body{#1}\loopdoxxx}
-\def\loopdoxxx{\let\next=\relax\body\let\next=\loopdoxxx\fi\next}
 
-\def\indexinputprocessing{%
-  \ifeof1
-    \let\firsttoken\relax
+% If the index file starts with a backslash, forgo reading the index
+% file altogether.  If somebody upgrades texinfo.tex they may still have
+% old index files using \ as the escape character.  Reading this would
+% at best lead to typesetting garbage, at worst a TeX syntax error.
+\def\printindexzz#1#2\finish{%
+  \expandafter\ifx\csname SETtxiindexescapeisbackslash\endcsname\relax
+    \uccode`\~=`\\ \uppercase{\if\noexpand~}\noexpand#1
+      \expandafter\ifx\csname SETtxiskipindexfileswithbackslash\endcsname\relax
+\errmessage{%
+ERROR: A sorted index file in an obsolete format was skipped.  
+To fix this problem, please upgrade your version of 'texi2dvi'
+or 'texi2pdf' to that at <https://ftp.gnu.org/gnu/texinfo>.
+If you are using an old version of 'texindex' (part of the Texinfo 
+distribution), you may also need to upgrade to a newer version (at least 6.0).
+You may be able to typeset the index if you run
+'texindex \jobname.\indexname' yourself.
+You could also try setting the 'txiindexescapeisbackslash' flag by 
+running a command like
+'texi2dvi -t "@set txiindexescapeisbackslash" \jobname.texi'.  If you do 
+this, Texinfo will try to use index files in the old format.
+If you continue to have problems, deleting the index files and starting again 
+might help (with 'rm \jobname.?? \jobname.??s')%
+}%
+      \else
+        (Skipped sorted index file in obsolete format)
+      \fi
+    \else
+      \begindoublecolumns
+      \input \jobname.\indexname s
+      \enddoublecolumns
+    \fi
   \else
-    \edef\act{\gdef\noexpand\firsttoken{\getfirsttoken\nextline}}%
-    \act
+    \message{trying to print index \indexname}%
+    \begindoublecolumns
+    \catcode`\\=0\relax
+    \catcode`\@=12\relax
+    \input \jobname.\indexname s
+    \enddoublecolumns
   \fi
 }
-\def\getfirsttoken#1{\expandafter\getfirsttokenx#1\endfirsttoken}
-\long\def\getfirsttokenx#1#2\endfirsttoken{\noexpand#1}
-
 
 % These macros are used by the sorted index file itself.
 % Change them to control the appearance of the index.
@@ -5554,12 +5551,19 @@ end
 \catcode`\|=13 \catcode`\<=13 \catcode`\>=13 \catcode`\+=13 \catcode`\"=13
 \catcode`\$=3
 \gdef\initialglyphs{%
+  % special control sequences used in the index sort key
+  \let\indexlbrace\{%
+  \let\indexrbrace\}%
+  \let\indexatchar\@%
+  \def\indexbackslash{\math{\backslash}}%
+  %
   % Some changes for non-alphabetic characters.  Using the glyphs from the
   % math fonts looks more consistent than the typewriter font used elsewhere
   % for these characters.
-  \def\indexbackslash{\math{\backslash}}%
-  \let\\=\indexbackslash
+  \uccode`\~=`\\ \uppercase{\def~{\math{\backslash}}}
   %
+  % In case @\ is used for backslash
+  \uppercase{\let\\=~}
   % Can't get bold backslash so don't use bold forward slash
   \catcode`\/=13
   \def/{{\secrmnotbold \normalslash}}%
@@ -5619,12 +5623,6 @@ 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 \insertentrybox.
-    \let\domark\relax
-    %
     % Start a new paragraph if necessary, so our assignments below can't
     % affect previous text.
     \par
@@ -5657,35 +5655,31 @@ end
 \gdef\finishentry#1{%
     \egroup % end box A
     \dimen@ = \wd\boxA % Length of text of entry
-    \global\setbox\boxA=\hbox\bgroup\unhbox\boxA
-    % #1 is the page number.
-    %
-    % Get the width of the page numbers, and only use
-    % leaders if they are present.
-    \global\setbox\boxB = \hbox{#1}%
-    \ifdim\wd\boxB = 0pt
-      \null\nobreak\hfill\ %
-    \else
-      %
-      \null\nobreak\indexdotfill % Have leaders before the page number.
+    \global\setbox\boxA=\hbox\bgroup
+      \unhbox\boxA
+      % #1 is the page number.
       %
-      \ifpdf
-        \pdfgettoks#1.%
-        \hskip\skip\thinshrinkable\the\toksA
+      % Get the width of the page numbers, and only use
+      % leaders if they are present.
+      \global\setbox\boxB = \hbox{#1}%
+      \ifdim\wd\boxB = 0pt
+        \null\nobreak\hfill\ %
       \else
-        \ifx\XeTeXrevision\thisisundefined
-          \hskip\skip\thinshrinkable #1%
-        \else
+        %
+        \null\nobreak\indexdotfill % Have leaders before the page number.
+        %
+        \ifpdforxetex
           \pdfgettoks#1.%
           \hskip\skip\thinshrinkable\the\toksA
+        \else
+          \hskip\skip\thinshrinkable #1%
         \fi
       \fi
-    \fi
     \egroup % end \boxA
     \ifdim\wd\boxB = 0pt
-      \global\setbox\entrybox=\vbox{\unhbox\boxA}%
-    \else
-    \global\setbox\entrybox=\vbox\bgroup
+      \noindent\unhbox\boxA\par
+      \nobreak
+    \else\bgroup
       % We want the text of the entries to be aligned to the left, and the
       % page numbers to be aligned to the right.
       %
@@ -5751,55 +5745,11 @@ end
     \egroup % The \vbox
     \fi
   \endgroup
-  \dotheinsertentrybox
 }}
 
 \newskip\thinshrinkable
 \skip\thinshrinkable=.15em minus .15em
 
-\newbox\entrybox
-\def\insertentrybox{%
-  \ourunvbox\entrybox
-}
-
-% default definition
-\let\dotheinsertentrybox\insertentrybox
-
-% 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
-  }%
-  \setbox\delayedbox=\box\interbox
-  \ifdim\ht#1=0pt\else
-    \ourunvbox#1 % Repeat on what's left of the box
-    \nobreak
-  \fi
-  \box\delayedbox
-\egroup
-}
-\newbox\delayedbox
-\newbox\interbox
-
-% 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
-% widowed index entries.
-\def\dotheinsertentryboxwithpenalty{%
-  \ifx\firsttoken\isentry
-  \else
-    \penalty 9000
-  \fi
-  \insertentrybox
-}
-\def\isentry{\entry}%
-
 % Like plain.tex's \dotfill, except uses up at least 1 em.
 % The filll stretch here overpowers both the fil and fill stretch to push
 % the page number to the right.
@@ -5809,24 +5759,15 @@ end
 
 \def\primary #1{\line{#1\hfil}}
 
-\newskip\secondaryindent \secondaryindent=0.5cm
-\def\secondary#1#2{{%
-  \parfillskip=0in
-  \parskip=0in
-  \hangindent=1in
-  \hangafter=1
-  \noindent\hskip\secondaryindent\hbox{#1}\indexdotfill
-  \ifpdf
-    \pdfgettoks#2.\ \the\toksA % The page number ends the paragraph.
-  \else
-    \ifx\XeTeXrevision\thisisundefined
-      #2
-    \else
-      \pdfgettoks#2.\ \the\toksA % The page number ends the paragraph.
-    \fi
-  \fi
-  \par
-}}
+\def\secondary{\indententry{0.5cm}}
+\def\tertiary{\indententry{1cm}}
+
+\def\indententry#1#2#3{%
+  \bgroup
+  \leftskip=#1
+  \entry{#2}{#3}%
+  \egroup
+}
 
 % Define two-column mode, which we use to typeset indexes.
 % Adapted from the TeXbook, page 416, which is to say,
@@ -5844,17 +5785,6 @@ end
   \output = {%
     \savetopmark
     %
-    % Here is a possibility not foreseen in manmac: if we accumulate a
-    % whole lot of material, we might end up calling this \output
-    % routine twice in a row (see the doublecol-lose test, which is
-    % essentially a couple of indexes with @setchapternewpage off).  In
-    % that case we just ship out what is in \partialpage with the normal
-    % output routine.  Generally, \partialpage will be empty when this
-    % runs and this will be a no-op.  See the indexspread.tex test case.
-    \ifvoid\partialpage \else
-      \onepageout{\pagecontents\partialpage}%
-    \fi
-    %
     \global\setbox\partialpage = \vbox{%
       % Unvbox the main output page.
       \unvbox\PAGE
@@ -6134,11 +6064,9 @@ end
 
 % @raisesections: treat @section as chapter, @subsection as section, etc.
 \def\raisesections{\global\advance\secbase by -1}
-\let\up=\raisesections % original BFox name
 
 % @lowersections: treat @chapter as section, @section as subsection, etc.
 \def\lowersections{\global\advance\secbase by 1}
-\let\down=\lowersections % original BFox name
 
 % we only have subsub.
 \chardef\maxseclevel = 3
@@ -6790,13 +6718,8 @@ end
   % 1 and 2 (the page numbers aren't printed), and so are the first
   % two pages of the document.  Thus, we'd have two destinations named
   % `1', and two named `2'.
-  \ifpdf
+  \ifpdforxetex
     \global\pdfmakepagedesttrue
-  \else
-    \ifx\XeTeXrevision\thisisundefined
-    \else
-      \global\pdfmakepagedesttrue
-    \fi
   \fi
 }
 
@@ -7159,11 +7082,7 @@ end
 
 % @cartouche ... @end cartouche: draw rectangle w/rounded corners around
 % environment contents.
-\font\circle=lcircle10
-\newdimen\circthick
-\newdimen\cartouter\newdimen\cartinner
-\newskip\normbskip\newskip\normpskip\newskip\normlskip
-\circthick=\fontdimen8\circle
+
 %
 \def\ctl{{\circle\char'013\hskip -6pt}}% 6pt from pl file: 1/2charwidth
 \def\ctr{{\hskip 6pt\circle\char'010}}
@@ -7178,7 +7097,18 @@ end
 %
 \newskip\lskip\newskip\rskip
 
+% only require the font if @cartouche is actually used
+\def\cartouchefontdefs{%
+  \font\circle=lcircle10\relax
+  \circthick=\fontdimen8\circle
+}
+\newdimen\circthick
+\newdimen\cartouter\newdimen\cartinner
+\newskip\normbskip\newskip\normpskip\newskip\normlskip
+
+
 \envdef\cartouche{%
+  \cartouchefontdefs
   \ifhmode\par\fi  % can't be in the midst of a paragraph.
   \startsavinginserts
   \lskip=\leftskip \rskip=\rightskip
@@ -8050,36 +7980,18 @@ end
   }
 \fi
 
-% alias because \c means cedilla in @tex or @math
-\let\texinfoc=\c
-
-\newcount\savedcatcodeone
-\newcount\savedcatcodetwo
-
 % Used at the time of macro expansion.
 % Argument is macro body with arguments substituted
 \def\scanmacro#1{%
   \newlinechar`\^^M
   \def\xeatspaces{\eatspaces}%
   %
-  % Temporarily undo catcode changes of \printindex.  Set catcode of @ to
-  % 0 so that @-commands in macro expansions aren't printed literally when 
-  % formatting an index file, where \ is used as the escape character.
-  \savedcatcodeone=\catcode`\@
-  \savedcatcodetwo=\catcode`\\
-  \catcode`\@=0
-  \catcode`\\=\active
-  %
   % Process the macro body under the current catcode regime.
-  \scantokens{#1@texinfoc}%
-  %
-  \catcode`\@=\savedcatcodeone
-  \catcode`\\=\savedcatcodetwo
+  \scantokens{#1@comment}%
   %
-  % The \texinfoc is to remove the \newlinechar added by \scantokens, and
-  % can be noticed by \parsearg.
-  %   We avoid surrounding the call to \scantokens with \bgroup and \egroup
-  % to allow macros to open or close groups themselves.
+  % The \comment is to remove the \newlinechar added by \scantokens, and
+  % can be noticed by \parsearg.  Note \c isn't used because this means cedilla 
+  % in math mode.
 }
 
 % Used for copying and captions
@@ -8180,12 +8092,14 @@ end
 \def\macroargctxt{%
   \scanctxt
   \catcode`\ =\active
+  \catcode`\@=\other
   \catcode`\^^M=\other
   \catcode`\\=\active
 }
 
 \def\macrolineargctxt{% used for whole-line arguments without braces
   \scanctxt
+  \catcode`\@=\other
   \catcode`\{=\other
   \catcode`\}=\other
 }
@@ -8749,9 +8663,29 @@ end
 % also remove a trailing comma, in case of something like this:
 % @node Help-Cross,  ,  , Cross-refs
 \def\donode#1 ,#2\finishnodeparse{\dodonode #1,\finishnodeparse}
-\def\dodonode#1,#2\finishnodeparse{\gdef\lastnode{#1}}
+\def\dodonode#1,#2\finishnodeparse{\gdef\lastnode{#1}\omittopnode}
+
+% Used so that the @top node doesn't have to be wrapped in an @ifnottex
+% conditional.
+% \doignore goes to more effort to skip nested conditionals but we don't need 
+% that here.
+\def\omittopnode{%
+   \ifx\lastnode\wordTop
+   \expandafter\ignorenode\fi
+}
+\def\wordTop{Top}
+
+% Until the next @node or @bye command, divert output to a box that is not 
+% output.
+\def\ignorenode{\setbox\dummybox\vbox\bgroup\def\node{\egroup\node}%
+\ignorenodebye
+}
+
+{\let\bye\relax
+\gdef\ignorenodebye{\let\bye\ignorenodebyedef}
+\gdef\ignorenodebyedef{\egroup(`Top' node ignored)\bye}}
+% The redefinition of \bye here is because it is declared \outer
 
-\let\nwnode=\node
 \let\lastnode=\empty
 
 % Write a cross-reference definition for the current node.  #1 is the
@@ -9226,19 +9160,6 @@ end
   \catcode`\^^]=\other
   \catcode`\^^^=\other
   \catcode`\^^_=\other
-  % It was suggested to set the catcode of ^ to 7, which would allow ^^e4 etc.
-  % in xref tags, i.e., node names.  But since ^^e4 notation isn't
-  % supported in the main text, it doesn't seem desirable.  Furthermore,
-  % that is not enough: for node names that actually contain a ^
-  % character, we would end up writing a line like this: 'xrdef {'hat
-  % b-title}{'hat b} and \xrdef does a \csname...\endcsname on the first
-  % argument, and \hat is not an expandable control sequence.  It could
-  % all be worked out, but why?  Either we support ^^ or we don't.
-  %
-  % The other change necessary for this was to define \auxhat:
-  % \def\auxhat{\def^{'hat }}% extra space so ok if followed by letter
-  % and then to call \auxhat in \setq.
-  %
   \catcode`\^=\other
   %
   % Special characters.  Should be turned off anyway, but...
@@ -9256,14 +9177,7 @@ end
   \catcode`\%=\other
   \catcode`+=\other % avoid \+ for paranoia even though we've turned it off
   %
-  % This is to support \ in node names and titles, since the \
-  % characters end up in a \csname.  It's easier than
-  % leaving it active and making its active definition an actual \
-  % character.  What I don't understand is why it works in the *value*
-  % of the xrdef.  Seems like it should be a catcode12 \, and that
-  % should not typeset properly.  But it works, so I'm moving on for
-  % now.  --karl, 15jan04.
-  \catcode`\\=\other
+  \catcode`\\=\active
   %
   % @ is our escape character in .aux files, and we need braces.
   \catcode`\{=1
@@ -11534,11 +11448,9 @@ directory should work if nowhere else does.}
 % \backslashcurfont outputs one backslash character in current font,
 % as in \char`\\.
 \global\chardef\backslashcurfont=`\\
-\global\let\rawbackslashxx=\backslashcurfont  % let existing .??s files work
 
-% \realbackslash is an actual character `\' with catcode other, and
-% \doublebackslash is two of them (for the pdf outlines).
-{\catcode`\\=\other @gdef@realbackslash{\} @gdef@doublebackslash{\\}}
+% \realbackslash is an actual character `\' with catcode other.
+{\catcode`\\=\other @gdef@realbackslash{\}}
 
 % In Texinfo, backslash is an active character; it prints the backslash
 % in fixed width font.
@@ -11556,10 +11468,8 @@ directory should work if nowhere else does.}
 @def@ttbackslash{{@tt @ifmmode @mathchar29020 @else @backslashcurfont @fi}}
 @let@backslashchar = @ttbackslash % @backslashchar{} is for user documents.
 
-% \rawbackslash defines an active \ to do \backslashcurfont.
 % \otherbackslash defines an active \ to be a literal `\' character with
-% catcode other.  We switch back and forth between these.
-@gdef@rawbackslash{@let\=@backslashcurfont}
+% catcode other.
 @gdef@otherbackslash{@let\=@realbackslash}
 
 % Same as @turnoffactive except outputs \ as {\tt\char`\\} instead of
@@ -11631,7 +11541,7 @@ directory should work if nowhere else does.}
   @ifx\@eatinput @let\ = @ttbackslash @fi
   @catcode13=5 % regular end of line
   @enableemergencynewline
-  @let@c=@texinfoc
+  @let@c=@comment
   @let@parsearg@originalparsearg
   % Also turn back on active characters that might appear in the input
   % file name, in case not using a pre-dumped format.
diff --git a/doc/misc/tramp.texi b/doc/misc/tramp.texi
index ca86458e903..2eb5b45eb2a 100644
--- a/doc/misc/tramp.texi
+++ b/doc/misc/tramp.texi
@@ -545,7 +545,7 @@ file system), @file{@trampfn{dav,user@@host,/path/to/file}} and
 @cindex google drive
 @cindex method @option{nextcloud}
 @cindex @option{nextcloud} method
-@cindex owncloud
+@cindex nextcloud
 
 GVFS-based methods include also @acronym{GNOME} Online Accounts, which
 support the @option{Files} service.  These are the Google Drive file
@@ -1208,7 +1208,7 @@ directory have the same @code{display-name}, such a situation must be avoided.
 @cindex @acronym{GNOME} Online Accounts
 @cindex method @option{nextcloud}
 @cindex @option{nextcloud} method
-@cindex owncloud
+@cindex nextcloud
 
 As the name indicates, the method @option{nextcloud} allows you to
 access OwnCloud or NextCloud hosted files and directories.  Like the
@@ -3083,6 +3083,8 @@ host.  Example:
 @kbd{M-x auto-revert-tail-mode @key{RET}} runs similarly showing
 continuous output.
 
+@vindex shell-file-name
+@vindex shell-command-switch
 @code{shell-command} uses the variables @code{shell-file-name} and
 @code{shell-command-switch} in order to determine which shell to run.
 For remote hosts, their default values are @file{/bin/sh} and
@@ -3091,6 +3093,15 @@ uses @file{/system/bin/sh}).  Like the variables in the previous
 section, these variables can be changed via connection-local
 variables.
 
+@vindex async-shell-command-width
+@vindex COLUMNS@r{, environment variable}
+If Emacs supports the variable @code{async-shell-command-width} (since Emacs
+27.1), @value{tramp} cares about its value for asynchronous shell
+commands.  It specifies the number of display columns for command
+output.  For synchronous shell commands, a similar effect can be
+achieved by adding the environment variable @env{COLUMNS} to
+@code{tramp-remote-process-environment}.
+
 
 @subsection Running @code{eshell} on a remote host
 @cindex @code{eshell}