bug#17653: 24.3; Tramp doesn't detect ssh ControlMaster

[Michael Albinus <michael.albinus@gmx.de>]

Juliusz Chroboczek <jch@pps.univ-paris-diderot.fr> writes:

>> The native way to fix this in Tramp is tweaking `tramp-methods'. Add a
>> new method "myssh" with your preferred arguments.
>
> I know I can tweak it -- that's Emacs, I can advise any function -- but
> that's not the issue.  I expect Emacs to work optimally out of the box on
> an up-to-date Debian testing box, and this is not the case.

I don't speak about advising a function. `tramp-methods' is a variable
intended for configuration.

> Ideally, tramp should use a less fragile method to check for ControlMaster
> support; if that's not possible, it should at least use a regexp that's
> permissive enough to work on recent OpenSSH.
>
> Please fix Emacs to detect ControlMaster out of the box with recent Debian.

Well, in Emacs 24.4 the situation will be more complex, because Tramp
doesn't search for ControlMaster only, but also for ControlPersist. One
regexp alone won't fit.

That's why there exists the defconst `tramp-ssh-controlmaster-options'.
You could change it at your will.

However, I will check whether the situation with Debian could be
enhanced, somehow.

> -- Juliusz

Best regards, Michael.