Re: backup method

[Luc Teirlinck]

Stefan Monnier wrote:

   What Han's problem suggests is that we may want to add some
   variable that points to the director*ies* whose files should be
   considered "temporary".

Well, I guess that Emacs needs _one_ directory in which it puts
temporary files.

In as far as the other directories where files "should be considered
temporary", it is not clear what conclusions should be drawn out of
that.  Apparently the conclusions drawn out of it are that one should
make no backup files there (something with which some users seem to
strongly disagree, as I have noticed in some bug reports) and that
these files should keep using the edited version of the file, if the
file is edited.  The latter happens automatically if backup-by-copying
is true and if and only if a backup is made if backup-by-copying is nil.

I personally believe that the best solution would be to have a
customizable list of directories in which no backups are made.  The
default _could_ be the list of directories in which files should be
considered temporary.  Actually, the principle of least surprise would
suggest the empty list as default.  (Apparently some users have been
surprised and heavily inconvenienced when they found out that the
backup file they badly needed was not there in tmp.)

One could also use a customizable list of directories where backups
are made by copying, even if backup-by-copying is nil.  That one would
consist by default of the files in those temporary directories.

Sincerely,

Luc.