bug#23151: 25.1.50; Emacs should have a convenient command for saving unchanged buffers

[Lars Magne Ingebrigtsen]

During an unrelated discussion on emacs-devel, it turns out that
virtually everybody is in the habit of making a change, then deleting
the change, just to make `C-x C-s' work.  This means that there is a
need for Emacs to offer a command to save buffers, even if they aren't
changed.

(All the electricity in the Emacs modes means that even if you find
typing `SPC DEL C-x C-s' convenient, sometimes it makes Stuff Happens,
and that DEL doesn't really undo what you've done.)

Several options exist:

1) Have the interactive `C-x C-s' command always save the buffer, no
matter whether it's unchanged or not.  I think many people would object
to this, as they're used to just `C-x C-s'-ing idly while thinking of
other things.

2) Have the prefix to that command save the unchanged buffer.  This
would be the obvious choice, but:

--------------
(save-buffer &optional ARG)

Save current buffer in visited file if modified.
Variations are described below.

By default, makes the previous version into a backup file
 if previously requested or if this is the first save.
Prefixed with one C-u, marks this version
 to become a backup when the next save is done.
Prefixed with two C-u’s,
 unconditionally makes the previous version into a backup file.
Prefixed with three C-u’s, marks this version
 to become a backup when the next save is done,
 and unconditionally makes the previous version into a backup file.
--------------

Eh.  Four `C-u's?  I don't think so.  We could bind `C-x C-s' to a new
`save-buffer-command' that has different prefix rules.  Does anybody use
the backup stuff?

3) Add a new keystroke.

4) Something else.



In GNU Emacs 25.1.50.20 (x86_64-unknown-linux-gnu, GTK+ Version 3.4.2)
 of 2016-03-28 built on stories
Repository revision: a30e7e12ed8465e2565dd318d921bc87f52ce18e
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-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no