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

[martin rudalics]

>>!       (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.