bug#19594: url-ftp: should not be aliased to url-file; url-file: use Tramp

[Stefan Kangas]

Ivan Shmakov <ivan@siamics.net> writes:

> Package:  emacs
> Severity: minor
>
>     As of 88bc8332eb14 (2015-01-07 13:51:41 +0000), url-ftp is
>     implemented as an alias to url-file, which results in the
>     following (unexpected) behavior.
>
> (let ((url-proxy-services nil))
>   (url-retrieve-synchronously "ftp://localhost/dev/null";))
>
>     Returns: a buffer.  Expected: failure, as there’s no FTP server
>     running on localhost.
>
> (let ((url-proxy-services nil))
>   (url-retrieve-synchronously "file://remote.example/dev/null"))
>
>     Results in a internal-ange-ftp-mode buffer opened.  Expected:
>     the contents of the file, as retrieved via Tramp.
>
>     I understand that FTP was once the only widespread file transfer
>     protocol /and/ that ange-ftp was once the only Emacs package
>     providing access to remote filesystems.  Now that Emacs has
>     Tramp, I see no reason for using ange-ftp for retrieving
>     resources denoted by file: scheme URIs, – unless so is the
>     preference of the user.
>
>     My suggestion would be that the FTP-specific code be split off
>     url-file.el into url-ftp.el (so that ftp: URIs would exclusively
>     denote resources available via FTP), /and/ new Tramp interface
>     (hopefully trivial) be coded into url-file.el.

If the long-term plan now is to phase out the entire url library,
perhaps we should close this as wontfix?

Best regards,
Stefan Kangas