BUG #6172: DROP EXTENSION error without CASCADE

The following bug has been logged online:

Bug reference: 6172
Logged by: Hitoshi Harada
Email address: umi(dot)tanuki(at)gmail(dot)com
PostgreSQL version: 9.1RC1
Operating system: Windows7
Description: DROP EXTENSION error without CASCADE
Details:

On pure-installed RC1 database, you can CREATE EXTENSION, but cannot DROP
it.

CREATE EXTENSION cube;
DROP EXTENSION cube;

ERROR: cannot drop extension cube because other objects depend on it
DETAIL: operator <>(cube,cube) depends on function cube_ne(cube,cube)
operator >(cube,cube) depends on function cube_gt(cube,cube)
operator <=(cube,cube) depends on function cube_le(cube,cube)
operator >=(cube,cube) depends on function cube_ge(cube,cube)
operator <@(cube,cube) depends on function cube_contained(cube,cube)
operator ~(cube,cube) depends on function cube_contained(cube,cube)
HINT: Use DROP ... CASCADE to drop the dependent objects too.

DROP EXTENSION ... CASCADE; works but without CASCADE should work as source
build on Linux does it.