Subject: bug#17361: Tramp does not save history across sessions.

From: Eli Zaretskii <[email-masked]>
Date: Mon, 28 Apr 2014 18:26:45 +0300

> From: Michael Albinus <[email-masked]>
> Date: Mon, 28 Apr 2014 15:45:34 +0200
> Cc: [email-masked]
> 
> So we need to support several sentinels per process.

Or a protocol: if you install a sentinel, and another one already
exists, call it after yours.