And I don't understand why Tramp shall refuse to provide file name
completion once the user has asked for this explicitely. Typing
"/ssh:host:tmp/em TAB" is a very convincing argument to me, that the
user wants a new connection to "host", and she wants also to get
completion for "tmp/ema" on that host. I cannot see why Tramp shall be
forbidden to do this.
But again, *this* bug report is not about what Tramp does when
non-essential is bound to non-nil. *This* bug report is about, that
non-essential is nil, although file name completion is
undergoing. Remember, we are in eshell, the user has typed "cd /", and
afterwards she has called pcomplete.