id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30888	Dangerous behavior for queryset combinator	wckao	nobody	"Although it is documented that after queryset combinator is used ( union / intersection / difference ), ""only LIMIT, OFFSET, COUNT(*), ORDER BY, and specifying columns (i.e. slicing, count(), order_by(), and values()/values_list()) are allowed on the resulting QuerySet"". 

But when other unsupported filtering is used, it is simply ignored instead of throwing an exception, which can be dangerous and hard to discover/debug.

For example,

{{{
User.objects.filter(is_active=True).union(User.objects.filter(is_active=False)).filter(is_active=True)
}}}
will actually return all the User instead of just active user, without any warning or exception.
the last filter is simply discarded and ignored.
"	Uncategorized	closed	Database layer (models, ORM)	2.2	Normal	duplicate	queryset combinator filter		Unreviewed	0	0	0	0	0	0