Bug with specific-schema extensions

This happens on 9.4.1 and HEAD.

The variant extension is locked to a specific schema by it's control file:
decibel@decina:[23:53]~/git/variant (master %=)$cat variant.control
# variant extension
comment = 'Variant data type for PostgreSQL'
default_version = '1.0.0-beta3'
relocatable = false
schema = 'variant'

CREATE EXTENSION creates the variant schema for me, but it leaves it 
behind when I drop the extension. I assume this is a bug and not by design?

decibel@decina.attlocal=# \dn List of schemas  Name  |  Owner
--------+--------- public | decibel
(1 row)

decibel@decina.attlocal=# BEGIN;
BEGIN
decibel@decina.attlocal=#* CREATE EXTENSION variant;
CREATE EXTENSION
decibel@decina.attlocal=#* \dn  List of schemas   Name   |  Owner
----------+--------- _variant | decibel public   | decibel variant  | decibel
(3 rows)

decibel@decina.attlocal=#* DROP EXTENSION variant;
DROP EXTENSION
decibel@decina.attlocal=#* \dn  List of schemas  Name   |  Owner
---------+--------- public  | decibel variant | decibel
(2 rows)

decibel@decina.attlocal=#* DROP SCHEMA variant ;
DROP SCHEMA
decibel@decina.attlocal=#* \q
-- 
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com