Fix some DOS line-ending inconsistencies introduced with arch-tag:

[gnu-emacs] / lispref / backups.texi

diff --git a/lispref/backups.texi b/lispref/backups.texi
index 3a8221bab4f8c961b78db309da36ef45b1234246..d4809369bcc91cbebc04bfceab1a20bfe9486ef7 100644 (file)
--- a/lispref/backups.texi
+++ b/lispref/backups.texi
@@ -1,6 +1,7 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Emacs Lisp Reference Manual.
 @c -*-texinfo-*-
 @c This is part of the GNU Emacs Lisp Reference Manual.

-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc. 
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1999
+@c   Free Software Foundation, Inc.

 @c See the file elisp.texi for copying conditions.
 @setfilename ../info/backups
 @node Backups and Auto-Saving, Buffers, Files, Top
 @c See the file elisp.texi for copying conditions.
 @setfilename ../info/backups
 @node Backups and Auto-Saving, Buffers, Files, Top


@@ -61,7 +62,7 @@ saving the buffer the first time.
 been backed up on account of this buffer.  If it is non-@code{nil}, then
 the backup file has been written.  Otherwise, the file should be backed
 up when it is next saved (if backups are enabled).  This is a
 been backed up on account of this buffer.  If it is non-@code{nil}, then
 the backup file has been written.  Otherwise, the file should be backed
 up when it is next saved (if backups are enabled).  This is a

-permanent local; @code{kill-local-variables} does not alter it.
+permanent local; @code{kill-all-local-variables} does not alter it.

 @end defvar
 
 @defopt make-backup-files
 @end defvar
 
 @defopt make-backup-files


@@ -73,13 +74,13 @@ is @code{nil} (see below).
 The following example shows how to change the @code{make-backup-files}
 variable only in the Rmail buffers and not elsewhere.  Setting it
 @code{nil} stops Emacs from making backups of these files, which may
 The following example shows how to change the @code{make-backup-files}
 variable only in the Rmail buffers and not elsewhere.  Setting it
 @code{nil} stops Emacs from making backups of these files, which may

-save disk space.  (You would put this code in your @file{.emacs} file.)
+save disk space.  (You would put this code in your init file.)

 
 @smallexample
 @group
 
 @smallexample
 @group

-(add-hook 'rmail-mode-hook 
+(add-hook 'rmail-mode-hook

           (function (lambda ()
           (function (lambda ()

-                      (make-local-variable 
+                      (make-local-variable

                        'make-backup-files)
                       (setq make-backup-files nil))))
 @end group
                        'make-backup-files)
                       (setq make-backup-files nil))))
 @end group


@@ -93,14 +94,10 @@ one argument, a file name to consider.  If the function returns
 @code{nil}, backups are disabled for that file.  Otherwise, the other
 variables in this section say whether and how to make backups.
 
 @code{nil}, backups are disabled for that file.  Otherwise, the other
 variables in this section say whether and how to make backups.
 

-The default value is this:
-
-@example
-(lambda (name)
-  (or (< (length name) 5)
-      (not (string-equal "/tmp/"
-                         (substring name 0 5)))))
-@end example
+@findex normal-backup-enable-predicate
+The default value is @code{normal-backup-enable-predicate}, which checks
+for files in @code{temporary-file-directory} and
+@code{small-temporary-file-directory}.

 @end defvar
 
 @defvar backup-inhibited
 @end defvar
 
 @defvar backup-inhibited


@@ -116,11 +113,51 @@ its value.  Major modes should not set this variable---they should set
 @code{make-backup-files} instead.
 @end defvar
 
 @code{make-backup-files} instead.
 @end defvar
 

+@defvar backup-directory-alist
+@tindex backup-directory-alist
+This variable's value is an alist of filename patterns and backup
+directory names.  Each element looks like
+@smallexample
+(@var{regexp} . @var{directory})
+@end smallexample
+
+@noindent
+Backups of files with names matching @var{regexp} will be made in
+@var{directory}.  @var{directory} may be relative or absolute.  If it is
+absolute, so that all matching files are backed up into the same
+directory, the file names in this directory will be the full name of the
+file backed up with all directory separators changed to @samp{!} to
+prevent clashes.  This will not work correctly if your filesystem
+truncates the resulting name.
+
+For the common case of all backups going into one directory, the alist
+should contain a single element pairing @samp{"."} with the appropriate
+directory name.
+
+If this variable is @code{nil}, or it fails to match a filename, the
+backup is made in the original file's directory.
+
+On MS-DOS filesystems without long names this variable is always
+ignored.
+@end defvar
+
+@defvar make-backup-file-name-function
+@tindex make-backup-file-name-function
+This variable's value is a function to use for making backups instead
+of the default @code{make-backup-file-name}.  A value of @code{nil}
+gives the default @code{make-backup-file-name} behaviour.
+
+This could be buffer-local to do something special for specific
+files.  If you define it, you may need to change
+@code{backup-file-name-p} and @code{file-name-sans-versions} too.
+@end defvar
+
+

 @node Rename or Copy
 @subsection Backup by Renaming or by Copying?
 @cindex backup files, how to make them
 
 @node Rename or Copy
 @subsection Backup by Renaming or by Copying?
 @cindex backup files, how to make them
 

-  There are two ways that Emacs can make a backup file: 
+  There are two ways that Emacs can make a backup file:

 
 @itemize @bullet
 @item
 
 @itemize @bullet
 @item


@@ -179,6 +216,19 @@ This variable is significant only if @code{backup-by-copying} is
 non-@code{nil}.
 @end defvar
 
 non-@code{nil}.
 @end defvar
 

+@defvar backup-by-copying-when-privileged-mismatch
+This variable, if non-@code{nil}, specifies the same behavior as
+@code{backup-by-copying-when-mismatch}, but only for certain user-id
+values: namely, those less than or equal to a certain number.  You set
+this variable to that number.
+
+Thus, if you set @code{backup-by-copying-when-privileged-mismatch}
+to 0, backup by copying is done for the superuser only,
+when necessary to prevent a change in the owner of the file.
+
+The default is 200.
+@end defvar
+

 @node Numbered Backups
 @subsection Making and Deleting Numbered Backup Files
 
 @node Numbered Backups
 @subsection Making and Deleting Numbered Backup Files
 


@@ -226,11 +276,11 @@ backup version 3 is excess.  The function @code{find-backup-file-name}
 (@pxref{Backup Names}) is responsible for determining which backup
 versions to delete, but does not delete them itself.
 
 (@pxref{Backup Names}) is responsible for determining which backup
 versions to delete, but does not delete them itself.
 

-@tindex delete-old-versions

 @defopt delete-old-versions
 @defopt delete-old-versions

-If this variable is non-@code{nil}, then saving a file deletes excess
-backup versions silently.  Otherwise, it asks the user whether to delete
-them.
+If this variable is @code{t}, then saving a file deletes excess
+backup versions silently.  If it is @code{nil}, that means
+to ask for confirmation before deleting excess backups.
+Otherwise, they are not deleted at all.

 @end defopt
 
 @defopt dired-kept-versions
 @end defopt
 
 @defopt dired-kept-versions


@@ -270,7 +320,7 @@ The standard definition of this function is as follows:
 (defun backup-file-name-p (file)
   "Return non-nil if FILE is a backup file \
 name (numeric or not)..."
 (defun backup-file-name-p (file)
   "Return non-nil if FILE is a backup file \
 name (numeric or not)..."

-  (string-match "~$" file))
+  (string-match "~\\'" file))

 @end group
 @end smallexample
 
 @end group
 @end smallexample
 


@@ -289,13 +339,13 @@ This function returns a string that is the name to use for a
 non-numbered backup file for file @var{filename}.  On Unix, this is just
 @var{filename} with a tilde appended.
 
 non-numbered backup file for file @var{filename}.  On Unix, this is just
 @var{filename} with a tilde appended.
 

-The standard definition of this function is as follows:
+The standard definition of this function, on most operating systems, is
+as follows:

 
 @smallexample
 @group
 (defun make-backup-file-name (file)
 
 @smallexample
 @group
 (defun make-backup-file-name (file)

-  "Create the non-numeric backup file name for FILE.
-@dots{}"
+  "Create the non-numeric backup file name for FILE..."

   (concat file "~"))
 @end group
 @end smallexample
   (concat file "~"))
 @end group
 @end smallexample


@@ -307,7 +357,9 @@ to prepend a @samp{.} in addition to appending a tilde:
 @smallexample
 @group
 (defun make-backup-file-name (filename)
 @smallexample
 @group
 (defun make-backup-file-name (filename)

-  (concat "." filename "~"))
+  (expand-file-name
+    (concat "." (file-name-nondirectory filename) "~")
+    (file-name-directory filename)))

 @end group
 
 @group
 @end group
 
 @group


@@ -315,6 +367,11 @@ to prepend a @samp{.} in addition to appending a tilde:
      @result{} ".backups.texi~"
 @end group
 @end smallexample
      @result{} ".backups.texi~"
 @end group
 @end smallexample

+
+Some parts of Emacs, including some Dired commands, assume that backup
+file names end with @samp{~}.  If you do not follow that convention, it
+will not cause serious problems, but these commands may give
+less-than-desirable results.

 @end defun
 
 @defun find-backup-file-name filename
 @end defun
 
 @defun find-backup-file-name filename


@@ -348,7 +405,7 @@ This function returns the name of the most recent backup file for
 
 Some file comparison commands use this function so that they can
 automatically compare a file with its most recent backup.
 
 Some file comparison commands use this function so that they can
 automatically compare a file with its most recent backup.

-@end defun 
+@end defun

 
 @node Auto-Saving
 @section Auto-Saving
 
 @node Auto-Saving
 @section Auto-Saving


@@ -358,7 +415,7 @@ automatically compare a file with its most recent backup.
 called @dfn{auto-saving}.  Auto-saving prevents you from losing more
 than a limited amount of work if the system crashes.  By default,
 auto-saves happen every 300 keystrokes, or after around 30 seconds of
 called @dfn{auto-saving}.  Auto-saving prevents you from losing more
 than a limited amount of work if the system crashes.  By default,
 auto-saves happen every 300 keystrokes, or after around 30 seconds of

-idle time.  @xref{Auto-Save, Auto-Save, Auto-Saving: Protection Against
+idle time.  @xref{Auto Save, Auto Save, Auto-Saving: Protection Against

 Disasters, emacs, The GNU Emacs Manual}, for information on auto-save
 for users.  Here we describe the functions used to implement auto-saving
 and the variables that control them.
 Disasters, emacs, The GNU Emacs Manual}, for information on auto-save
 for users.  Here we describe the functions used to implement auto-saving
 and the variables that control them.


@@ -371,7 +428,7 @@ should not be auto-saved.
 @example
 @group
 buffer-auto-save-file-name
 @example
 @group
 buffer-auto-save-file-name

-=> "/xcssun/users/rms/lewis/#files.texi#"
+     @result{} "/xcssun/users/rms/lewis/#backups.texi#"

 @end group
 @end example
 @end defvar
 @end group
 @end example
 @end defvar


@@ -379,29 +436,29 @@ buffer-auto-save-file-name
 @deffn Command auto-save-mode arg
 When used interactively without an argument, this command is a toggle
 switch: it turns on auto-saving of the current buffer if it is off, and
 @deffn Command auto-save-mode arg
 When used interactively without an argument, this command is a toggle
 switch: it turns on auto-saving of the current buffer if it is off, and

-vice-versa.  With an argument @var{arg}, the command turns auto-saving
+vice versa.  With an argument @var{arg}, the command turns auto-saving

 on if the value of @var{arg} is @code{t}, a nonempty list, or a positive
 integer.  Otherwise, it turns auto-saving off.
 @end deffn
 
 @defun auto-save-file-name-p filename
 This function returns a non-@code{nil} value if @var{filename} is a
 on if the value of @var{arg} is @code{t}, a nonempty list, or a positive
 integer.  Otherwise, it turns auto-saving off.
 @end deffn
 
 @defun auto-save-file-name-p filename
 This function returns a non-@code{nil} value if @var{filename} is a

-string that could be the name of an auto-save file.  It works based on
-knowledge of the naming convention for auto-save files: a name that
+string that could be the name of an auto-save file.  It assumes
+the usual naming convention for auto-save files: a name that

 begins and ends with hash marks (@samp{#}) is a possible auto-save file
 name.  The argument @var{filename} should not contain a directory part.
 
 @example
 @group
 (make-auto-save-file-name)
 begins and ends with hash marks (@samp{#}) is a possible auto-save file
 name.  The argument @var{filename} should not contain a directory part.
 
 @example
 @group
 (make-auto-save-file-name)

-     @result{} "/xcssun/users/rms/lewis/#files.texi#"
+     @result{} "/xcssun/users/rms/lewis/#backups.texi#"

 @end group
 @group
 @end group
 @group

-(auto-save-file-name-p "#files.texi#")
+(auto-save-file-name-p "#backups.texi#")

      @result{} 0
 @end group
 @group
      @result{} 0
 @end group
 @group

-(auto-save-file-name-p "files.texi")
+(auto-save-file-name-p "backups.texi")

      @result{} nil
 @end group
 @end example
      @result{} nil
 @end group
 @end example


@@ -424,15 +481,15 @@ correspondingly.
 
 @defun make-auto-save-file-name
 This function returns the file name to use for auto-saving the current
 
 @defun make-auto-save-file-name
 This function returns the file name to use for auto-saving the current

-buffer.  This is just the file name with hash marks (@samp{#}) appended
-and prepended to it.  This function does not look at the variable
-@code{auto-save-visited-file-name} (described below); you should check
-that before calling this function.
+buffer.  This is just the file name with hash marks (@samp{#}) prepended
+and appended to it.  This function does not look at the variable
+@code{auto-save-visited-file-name} (described below); callers of this
+function should check that variable first.

 
 @example
 @group
 (make-auto-save-file-name)
 
 @example
 @group
 (make-auto-save-file-name)

-     @result{} "/xcssun/users/rms/lewis/#backup.texi#"
+     @result{} "/xcssun/users/rms/lewis/#backups.texi#"

 @end group
 @end example
 
 @end group
 @end example
 


@@ -442,8 +499,7 @@ The standard definition of this function is as follows:
 @group
 (defun make-auto-save-file-name ()
   "Return file name to use for auto-saves \
 @group
 (defun make-auto-save-file-name ()
   "Return file name to use for auto-saves \

-of current buffer.
-@dots{}"
+of current buffer.."

   (if buffer-file-name
 @end group
 @group
   (if buffer-file-name
 @end group
 @group


@@ -469,10 +525,11 @@ file that you are editing.  Normally, this variable is @code{nil}, so
 auto-save files have distinct names that are created by
 @code{make-auto-save-file-name}.
 
 auto-save files have distinct names that are created by
 @code{make-auto-save-file-name}.
 

-When you change the value of this variable, the value does not take
-effect until the next time auto-save mode is reenabled in any given
-buffer.  If auto-save mode is already enabled, auto-saves continue to go
-in the same file name until @code{auto-save-mode} is called again.
+When you change the value of this variable, the new value does not take
+effect in an existing buffer until the next time auto-save mode is
+reenabled in it.  If auto-save mode is already enabled, auto-saves
+continue to go in the same file name until @code{auto-save-mode} is
+called again.

 @end defvar
 
 @defun recent-auto-save-p
 @end defvar
 
 @defun recent-auto-save-p


@@ -487,18 +544,23 @@ function returns @code{nil}.
 @end defun
 
 @defopt auto-save-interval
 @end defun
 
 @defopt auto-save-interval

-The value of this variable is the number of characters that Emacs
-reads from the keyboard between auto-saves.  Each time this many more
-characters are read, auto-saving is done for all buffers in which it is
+The value of this variable specifies how often to do auto-saving, in
+terms of number of input events.  Each time this many additional input
+events are read, Emacs does auto-saving for all buffers in which that is

 enabled.
 @end defopt
 
 @defopt auto-save-timeout
 The value of this variable is the number of seconds of idle time that
 should cause auto-saving.  Each time the user pauses for this long,
 enabled.
 @end defopt
 
 @defopt auto-save-timeout
 The value of this variable is the number of seconds of idle time that
 should cause auto-saving.  Each time the user pauses for this long,

-Emacs auto-saves any buffers that need it.  (Actually, the specified
-timeout is multiplied by a factor depending on the size of the current
-buffer.)
+Emacs does auto-saving for all buffers in which that is enabled.  (If
+the current buffer is large, the specified timeout is multiplied by a
+factor that increases as the size increases; for a million-byte
+buffer, the factor is almost 4.)
+
+If the value is zero or @code{nil}, then auto-saving is not done as a
+result of idleness, only after a certain number of input events as
+specified by @code{auto-save-interval}.

 @end defopt
 
 @defvar auto-save-hook
 @end defopt
 
 @defvar auto-save-hook


@@ -546,14 +608,15 @@ nothing.
 
 @defvar buffer-saved-size
 The value of this buffer-local variable is the length of the current
 
 @defvar buffer-saved-size
 The value of this buffer-local variable is the length of the current

-buffer as of the last time it was read in, saved, or auto-saved.  This is
+buffer, when it was last read in, saved, or auto-saved.  This is

 used to detect a substantial decrease in size, and turn off auto-saving
 in response.
 
 used to detect a substantial decrease in size, and turn off auto-saving
 in response.
 

-If it is -1, that means auto-saving is temporarily shut off in this
-buffer due to a substantial deletion.  Explicitly saving the buffer
-stores a positive value in this variable, thus reenabling auto-saving.
-Turning auto-save mode off or on also alters this variable.
+If it is @minus{}1, that means auto-saving is temporarily shut off in
+this buffer due to a substantial decrease in size.  Explicitly saving
+the buffer stores a positive value in this variable, thus reenabling
+auto-saving.  Turning auto-save mode off or on also updates this
+variable, so that the substantial decrease in size is forgotten.

 @end defvar
 
 @defvar auto-save-list-file-name
 @end defvar
 
 @defvar auto-save-list-file-name


@@ -564,14 +627,23 @@ enabled.  The first line gives the name of the visited file (it's empty
 if the buffer has none), and the second gives the name of the auto-save
 file.
 
 if the buffer has none), and the second gives the name of the auto-save
 file.
 

-If Emacs exits normally, it deletes this file.  If Emacs crashes, you
+When Emacs exits normally, it deletes this file; if Emacs crashes, you

 can look in the file to find all the auto-save files that might contain
 work that was otherwise lost.  The @code{recover-session} command uses
 can look in the file to find all the auto-save files that might contain
 work that was otherwise lost.  The @code{recover-session} command uses

-these files.
+this file to find them.

 
 

-The default name for this file is in your home directory and starts with
-@samp{.saves-}.  It also contains the Emacs process @sc{id} and the host
-name.
+The default name for this file specifies your home directory and starts
+with @samp{.saves-}.  It also contains the Emacs process @sc{id} and the
+host name.
+@end defvar
+
+@defvar auto-save-list-file-prefix
+@tindex auto-save-list-file-prefix
+After Emacs reads your init file, it initializes
+@code{auto-save-list-file-name} (if you have not already set it
+non-@code{nil}) based on this prefix, adding the host name and process
+ID.  If you set this to @code{nil} in your init file, then Emacs does
+not initialize @code{auto-save-list-file-name}.

 @end defvar
 
 @node Reverting
 @end defvar
 
 @node Reverting


@@ -582,17 +654,17 @@ about them, you can get rid of them by reading in the previous version
 of the file with the @code{revert-buffer} command.  @xref{Reverting, ,
 Reverting a Buffer, emacs, The GNU Emacs Manual}.
 
 of the file with the @code{revert-buffer} command.  @xref{Reverting, ,
 Reverting a Buffer, emacs, The GNU Emacs Manual}.
 

-@deffn Command revert-buffer &optional check-auto-save noconfirm
+@deffn Command revert-buffer &optional ignore-auto noconfirm

 This command replaces the buffer text with the text of the visited
 file on disk.  This action undoes all changes since the file was visited
 or saved.
 
 This command replaces the buffer text with the text of the visited
 file on disk.  This action undoes all changes since the file was visited
 or saved.
 

-If the argument @var{check-auto-save} is non-@code{nil}, and the
-latest auto-save file is more recent than the visited file,
-@code{revert-buffer} asks the user whether to use that instead.
-Otherwise, it always uses the text of the visited file itself.
-Interactively, @var{check-auto-save} is set if there is a numeric prefix
-argument.
+By default, if the latest auto-save file is more recent than the visited
+file, and the argument @var{ignore-auto} is @code{nil},
+@code{revert-buffer} asks the user whether to use that auto-save
+instead.  When you invoke this command interactively, @var{ignore-auto}
+is @code{t} if there is no numeric prefix argument; thus, the
+interactive default is not to check the auto-save file.

 
 Normally, @code{revert-buffer} asks for confirmation before it changes
 the buffer; but if the argument @var{noconfirm} is non-@code{nil},
 
 Normally, @code{revert-buffer} asks for confirmation before it changes
 the buffer; but if the argument @var{noconfirm} is non-@code{nil},


@@ -602,13 +674,24 @@ Reverting tries to preserve marker positions in the buffer by using the
 replacement feature of @code{insert-file-contents}.  If the buffer
 contents and the file contents are identical before the revert
 operation, reverting preserves all the markers.  If they are not
 replacement feature of @code{insert-file-contents}.  If the buffer
 contents and the file contents are identical before the revert
 operation, reverting preserves all the markers.  If they are not

-identical, reverting does change the buffer; then it preserves the
-markers in the unchanged text (if any) at the beginning and end of the
-buffer.  Preserving any additional markers would be problematical.
+identical, reverting does change the buffer; in that case, it preserves
+the markers in the unchanged text (if any) at the beginning and end of
+the buffer.  Preserving any additional markers would be problematical.

 @end deffn
 
 You can customize how @code{revert-buffer} does its work by setting
 @end deffn
 
 You can customize how @code{revert-buffer} does its work by setting

-these variables---typically, as buffer-local variables.
+the variables described in the rest of this section.
+
+@defvar revert-without-query
+This variable holds a list of files that should be reverted without
+query.  The value is a list of regular expressions.  If the visited file
+name matches one of these regular expressions, and the file has changed
+on disk but the buffer is not modified, then @code{revert-buffer}
+reverts the file without asking the user for confirmation.
+@end defvar
+
+  Some major modes customize @code{revert-buffer} by making
+buffer-local bindings for these variables:

 
 @defvar revert-buffer-function
 The value of this variable is the function to use to revert this buffer.
 
 @defvar revert-buffer-function
 The value of this variable is the function to use to revert this buffer.


@@ -618,32 +701,35 @@ usual way.
 
 Modes such as Dired mode, in which the text being edited does not
 consist of a file's contents but can be regenerated in some other
 
 Modes such as Dired mode, in which the text being edited does not
 consist of a file's contents but can be regenerated in some other

-fashion, give this variable a buffer-local value that is a function to
+fashion, can give this variable a buffer-local value that is a function to

 regenerate the contents.
 @end defvar
 
 @defvar revert-buffer-insert-file-contents-function
 regenerate the contents.
 @end defvar
 
 @defvar revert-buffer-insert-file-contents-function

-The value of this variable, if non-@code{nil}, is the function to use to
+The value of this variable, if non-@code{nil}, specifies the function to use to

 insert the updated contents when reverting this buffer.  The function
 receives two arguments: first the file name to use; second, @code{t} if
 the user has asked to read the auto-save file.
 insert the updated contents when reverting this buffer.  The function
 receives two arguments: first the file name to use; second, @code{t} if
 the user has asked to read the auto-save file.

+
+The reason for a mode to set this variable instead of
+@code{revert-buffer-function} is to avoid duplicating or replacing the
+rest of what @code{revert-buffer} does: asking for confirmation,
+clearing the undo list, deciding the proper major mode, and running the
+hooks listed below.

 @end defvar
 
 @defvar before-revert-hook
 @end defvar
 
 @defvar before-revert-hook

-This normal hook is run by @code{revert-buffer} before actually
+This normal hook is run by @code{revert-buffer} before

 inserting the modified contents---but only if
 @code{revert-buffer-function} is @code{nil}.
 inserting the modified contents---but only if
 @code{revert-buffer-function} is @code{nil}.

-
-Font Lock mode uses this hook to record that the buffer contents are no
-longer fontified.

 @end defvar
 
 @defvar after-revert-hook
 @end defvar
 
 @defvar after-revert-hook

-This normal hook is run by @code{revert-buffer} after actually inserting
+This normal hook is run by @code{revert-buffer} after inserting

 the modified contents---but only if @code{revert-buffer-function} is
 @code{nil}.
 the modified contents---but only if @code{revert-buffer-function} is
 @code{nil}.

-
-Font Lock mode uses this hook to recompute the fonts for the updated
-buffer contents.

 @end defvar
 
 @end defvar
 

+@ignore
+   arch-tag: 295a6321-e5ab-46d5-aef5-0bb4f447a67f
+@end ignore