>> Juri said recently that he uses some of the keys in M-g in the 
>> minibuffer, so I changed my mind, and I now think that it would be 
>> better to use 'M-g M-c' for this, which is unused, and does not hide 
>> the complete M-g map. Updated patch attached.  WDYT?
>
> Sure, `M-g M-c' is fine by me.  But could you send a new patch against 
> the current tree?  The previous version of the patch has already been 
> applied and pushed.
>

Hmmm...  Why did you remove "read-expression-switch-to-completions" from 
the patch?  I know that you can, in vanilla Emacs, achieve the same effect 
with TAB TAB C-- C-x o, which is I think too complicated.  Patch attached, 
against the current trunk.