bug#9591: 24.0.50; buffer name completion

[Stephen Berman]

On Mon, 26 Sep 2011 01:35:50 -0400 Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Stefan Monnier <monnier@iro.umontreal.ca>
>> Date: Sun, 25 Sep 2011 21:18:30 -0400
>> Cc: 9591@debbugs.gnu.org
>> 
>> > If I type C-x k mes TAB, it completes to ` *message-viewer RMAIL'.
>> 
>> Hmm... that's probably a bug of the `substring' completion-style
>
> But `substring' is not in the default value of completion-styles.  So
> how does it come into play here?

Via completion-category-overrides; with emacs -Q:

,----
| completion-category-overrides is a variable defined in `minibuffer.el'.
| Its value is ((buffer
|   (styles basic substring)))
| 
| 
| Documentation:
| List of overrides for specific categories.
| Each override has the shape (CATEGORY . ALIST) where ALIST is
| an association list that can specify properties such as:
| - `styles': the list of `completion-styles' to use for that category.
| - `cycle': the `completion-cycle-threshold' to use for that category.
| 
| You can customize this variable.
`----

Steve Berman