Re: backup-buffer-copy loops if old backup can't be deleted

[martin rudalics <rudalics@gmx.at>]

 >>! 	(dir (or (file-name-directory to-name)
 >>! 		 default-directory)))
 >>!     ;; Can't delete or create files in a read-only directory.
 >>!     (unless (file-writable-p dir)
 >>!       (signal 'file-error (list "Directory is not writable" dir)))
 >
 >
 > This seems a good idea, as deleting a backup file we won't be able to
 > recreate would be a bad move. However I guess there are filesystems out
 > there where a file might be undeletable even if its directory is
 > writable.

We could check (file-writable-p to-name) here too.

 >>+ 	    ;; FIXME does that every actually happen in practice?
 >>+ 	    ;; This is a potential infloop, which seems bad...
 >
 >
 > The more I think about it, the rarer this seems to me. In my last mail I
 > voted for a fixed maximum loop count, but by now I would even drop all
 > loops; they are simply not worth the effort I guess.

More so because saving and backing up can be emergency operations.