bug#70959: Tramp connection property can interact weirdly with cache

[Michael Albinus]

Dmitry Gutov <dmitry@gutov.dev> writes:

> I've used the recipe for "direct-async-processes" as suggested:
>
> (add-to-list 'tramp-connection-properties
>              (list (regexp-quote "/ssh:user@host:")
>                    "direct-async-process" t))
>
> and at first (the connection was already open) it didn't take
> effect. I think I had to kill the connection buffer for the new
> property to be used. Would be nice if this was instant.
>
> But also, after that I tried altering tramp-connection-properties back
> to disable direct-async-process for that host (for the purposes of
> testing and measuring things more precisely), and found that changing
> the variable doesn't bring the new behavior back. Restarting Emacs
> didn't bring the old (non-direct) behavior back either - I had to edit
> the ~/.emacs.d/tramp file by hand to remove that property.
>
> I think that's something that might confuse other users.

If you want to remove a property from the cache, you need to call one of
the tramp-cleanup* commands.  See (info "(tramp) Cleanup remote connections")