bug#81537: 32.0.50; Fixing icomplete-in-buffer requiring users to advice-add

>> I meant an option to display in-buffer icomplete completions without
>> typing TAB, i.e. like in the minibuffer.  But this would be a new feature.
>
> I think someone who wants that can use some advice.

This feature might require adding post-command-hook.

> Do you think the second-tab behaviour I've implemented is unwanted?

I already tried double TAB when you first mentioned it, but it
didn't work.  Now I see that the second TAB should follow 'C-M-i',
i.e. the complete key sequence to pop up the *Completions* buffer is
'C-M-i TAB'.  At least this could be mentioned in the documentation.