Commit 5b585857 authored by Anssi Kääriäinen's avatar Anssi Kääriäinen Committed by Tim Graham
Browse files

[1.8.x] Fixed #24752 -- query crash when reusing Case expressions 

Case expressions weren't copied deep enough (self.cases list was
reused resulting in an error).

Backport of 7b05d2fd from master
parent eb00b427

django/db/models/expressions.py

+5 −0
Original line number Diff line number Diff line
@@ -780,6 +780,11 @@ class Case(Expression): 
        c.default = c.default.resolve_expression(query, allow_joins, reuse, summarize, for_save)

        return c



    def copy(self):

        c = super(Case, self).copy()

        c.cases = c.cases[:]

        return c



    def as_sql(self, compiler, connection, template=None, extra=None):

        connection.ops.check_expression_support(self)

        if not self.cases:

docs/releases/1.8.2.txt

+3 −0
Original line number Diff line number Diff line
@@ -10,3 +10,6 @@ Bugfixes 
========



* Fixed check for template engine alias uniqueness (:ticket:`24685`).



* Fixed crash when reusing the same ``Case`` instance in a query

  (:ticket:`24752`).

tests/expressions_case/tests.py

+12 −0
Original line number Diff line number Diff line
@@ -274,6 +274,18 @@ class CaseExpressionTests(TestCase): 
            transform=attrgetter('integer', 'integer2')

        )



    def test_case_reuse(self):

        SOME_CASE = Case(

            When(pk=0, then=Value('0')),

            default=Value('1'),

            output_field=models.CharField(),

        )

        self.assertQuerysetEqual(

            CaseTestModel.objects.annotate(somecase=SOME_CASE).order_by('pk'),

            CaseTestModel.objects.annotate(somecase=SOME_CASE).order_by('pk').values_list('pk', 'somecase'),

            lambda x: (x.pk, x.somecase)

        )



    def test_aggregate(self):

        self.assertEqual(

            CaseTestModel.objects.aggregate(