* Reverting:: @code{revert-buffer}, and how to customize what it does.
@end menu
-@node Backup Files, Auto-Saving, Backups and Auto-Saving, Backups and Auto-Saving
+@node Backup Files
@section Backup Files
@cindex backup file
* Backup Names:: How backup file names are computed; customization.
@end menu
-@node Making Backups, Rename or Copy, Backup Files, Backup Files
+@node Making Backups
@subsection Making Backup Files
@defun backup-buffer
variable.
@end defvar
-@node Rename or Copy, Numbered Backups, Making Backups, Backup Files
+@node Rename or Copy
@subsection Backup by Renaming or by Copying?
@cindex backup files, how to make them
non-@code{nil}.
@end defvar
-@node Numbered Backups, Backup Names, Rename or Copy, Backup Files
+@node Numbered Backups
@subsection Making and Deleting Numbered Backup Files
If a file's name is @file{foo}, the names of its numbered backup
file. The default value is 2.
@end defopt
-@node Backup Names, , Numbered Backups, Backup Files
+@node Backup Names
@subsection Naming Backup Files
The functions in this section are documented mainly because you can
a file by default with its most recent backup.
@end defun
-@node Auto-Saving, Reverting, Backup Files, Backups and Auto-Saving
+@node Auto-Saving
@section Auto-Saving
@cindex auto-saving
nothing.
@end defun
-@node Reverting, , Auto-Saving, Backups and Auto-Saving
+@defvar buffer-saved-size
+The value of this buffer-local variable is the former length of the
+current buffer, as of the last time it was read in, saved or auto-saved.
+This is 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-save.
+Turning Auto-Save mode off or on also alters this variable.
+@end defvar
+
+@node Reverting
@section Reverting
If you have made extensive changes to a file and then change your mind