Re: Navigating completions from minibuffer

[Juri Linkov]

> minibuffer-choose-completion-or-exit submits the selected completion
> candidate, if any, ignoring the contents of the minibuffer.  But a
> user might select a completion candidate and then want to type
> something else in the minibuffer and submit what they typed.

Thanks, everything works nicely now except the special case
of completion-show-help=nil and completions-header-format=nil.

Initially the first completion is deselected, and <down> selects it.
But when the first key typed is M-<down> the second completion
is selected instead of the first because M-<down> moves to the
second column when point is between the first and second completions.

A possible workaround would be to check the special property
'first-completion'.  But then when the logic uses text properties,
why not to use more text properties that indicate that a candidate
is deselected (and remove highlighting in this case) instead of
moving point somewhere outside of the candidate?