Reimplement recent with-silent-modifications auto-save changes

* doc/lispref/buffers.texi (Buffer Modification): Document
buffer-modified-p returning `autosaved'.
* lisp/subr.el (with-silent-modifications): Use
restore-buffer-modified-p instead of altering the buffer modiff
(since this has other side effects like not updating after async
`display' changes.

* src/buffer.c (Fbuffer_modified_p): Allow returning whether the
buffer has been autosaved after changes.
(Frestore_buffer_modified_p): Allow adjusting whether the buffer
has been autosaved after changes.

* src/fileio.c (Fdo_auto_save): Refill the doc string.

1 files changed, 7 insertions, 4 deletions

diff --git a/src/fileio.c b/src/fileio.c
index 0610f7235a5..9da14c8f541 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -5972,14 +5972,17 @@ do_auto_save_eh (Lisp_Object ignore)
 
 DEFUN ("do-auto-save", Fdo_auto_save, Sdo_auto_save, 0, 2, "",
        doc: /* Auto-save all buffers that need it.
-This is all buffers that have auto-saving enabled
-and are changed since last auto-saved.
-Auto-saving writes the buffer into a file
-so that your editing is not lost if the system crashes.
+This is all buffers that have auto-saving enabled and are changed
+since last auto-saved.
+
+Auto-saving writes the buffer into a file so that your editing is not
+lost if the system crashes.
+
 This file is not the file you visited; that changes only when you save.
 Normally, run the normal hook `auto-save-hook' before saving.
 
 A non-nil NO-MESSAGE argument means do not print any message if successful.
+
 A non-nil CURRENT-ONLY argument means save only current buffer.  */)
   (Lisp_Object no_message, Lisp_Object current_only)
 {