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
19494	Defining __nonzero__ (or __len__) on model makes it impossible to use in GenericForeignKey	anonymous	nobody	"django/contrib/contenttypes/generic.py: 
GenericForeignKey.get_content_type:

    def get_content_type(self, obj=None, id=None, using=None):
        # Convenience function using get_model avoids a circular import when
        # using this model
        ContentType = get_model(""contenttypes"", ""contenttype"")
        if obj:
            return ContentType.objects.db_manager(obj._state.db).get_for_model(obj)

if obj: case does not execute for any object which has False boolean value. "	Bug	closed	contrib.contenttypes	1.4	Normal	duplicate			Unreviewed	0	0	0	0	0	0