Juri Linkov <juri@linkov.net> writes:

>>>>>>> Not sure if it's possible for RET to accept the selected candidate
>>>>>>> by default since users might prefer to accept text in the minibuffer.
>>>>>>
>>>>>> If there's a selected candidate, though, then users have already decided
>>>>>> to use M-<up>/M-<down> to interact with completions.  (Or they've
>>>>>> switched to the completions buffer and selected one)
>>>>>>
>>>>>> If they decide they don't want the candidate they selected, and want to
>>>>>> continue with text in the minibuffer, completion-auto-deselect will
>>>>>> automatically deselect the candidate if they type anything.
>>>>>>
>>>>>> I think these two facts combined make it possible for RET to accept the
>>>>>> selected candidate by default.
>>>>>
>>>>> Makes sense.  So we need to try how well it performs.
>>>>
>>>> How about this?
>>>
>>> Thanks, will try to use for a while.
>>
>> Any feedback on the patch?
>
> Everything looks good.  Could you send the final version of the patch?

Yes, attached.

(Note that this doesn't do the change I mentioned earlier of replacing
(get-buffer-window "*Completions*" 0) everywhere with
minibuffer--completions-visible, which probably should be done in a
separate patch, I can send that if you're up to install it now)