Re: tramp (2.0.25); saving remote buffer fails

[Michael Albinus]

address@hidden (Kai Großjohann) writes:

> Hm.  Maybe ange-ftp doesn't implement file-modes?  Maybe that's the
> reason?  Yeah, that's possible.  Oh, boy.

Indeed. ange-ftp supports (poorly) file-attributes, but file-modes:

(file-exists-p "/ftp:localhost:.emacs")
t

(file-modes "/ftp:localhost:.emacs")
nil

(file-attributes "/ftp:localhost:.emacs")
(nil -1 -1 -1 (0 0) (0 0) (0 0) -1 "-?????????" nil 2 -1)

> So maybe what should REALLY happen is that Tramp supports the
> operation find-backup-file-name and that tramp-ftp.el invokes
> ange-ftp correctly.  But I don't grok this sufficiently well.

The invocation of ange-ftp seems to be correct AFAICS.

I don't see the point why Tramp shall support find-backup-file-name
this case. This function is forwarded to ange-ftp always (because the
FTP method is active). ange-ftp hasn't implemented this method, but
forwards it to the default handler. And this one doesn't know what to
do:

(find-backup-file-name "/ftp:localhost:.emacs")
nil

According to the documentation this is a valid answer ("If the value
is nil, don't make a backup.") Usually there doesn't seem to be a
problem if ange-ftp is used without Tramp. Hmm.

Best regards, Michael.