[3.0.x] Fixed #30769 -- Fixed a crash when filtering against a subquery JSON/HStoreField annotation.

This was a regression introduced by 7deeabc7c7
to address CVE-2019-14234.

Thanks Tim Kleinschmidt for the report and Mariusz for the tests.

Backport of 6c3dfba892 from master

tests/postgres_tests/test_hstore.py

@@ -2,7 +2,7 @@ import json
 
 from django.core import checks, exceptions, serializers
 from django.db import connection
-from django.db.models.expressions import RawSQL
+from django.db.models.expressions import OuterRef, RawSQL, Subquery
 from django.forms import Form
 from django.test.utils import CaptureQueriesContext, isolate_apps
 
@@ -207,6 +207,12 @@ class TestQuerying(PostgreSQLTestCase):
             queries[0]['sql'],
         )
 
+    def test_obj_subquery_lookup(self):
+        qs = HStoreModel.objects.annotate(
+            value=Subquery(HStoreModel.objects.filter(pk=OuterRef('pk')).values('field')),
+        ).filter(value__a='b')
+        self.assertSequenceEqual(qs, self.objs[:2])
+
 
 @isolate_apps('postgres_tests')
 class TestChecks(PostgreSQLSimpleTestCase):

tests/postgres_tests/test_json.py

@@ -6,7 +6,7 @@ from decimal import Decimal
 from django.core import checks, exceptions, serializers
 from django.core.serializers.json import DjangoJSONEncoder
 from django.db import connection
-from django.db.models import Count, F, Q
+from django.db.models import Count, F, OuterRef, Q, Subquery
 from django.db.models.expressions import RawSQL
 from django.db.models.functions import Cast
 from django.forms import CharField, Form, widgets
@@ -303,6 +303,12 @@ class TestQuerying(PostgreSQLTestCase):
             [self.objs[7], self.objs[8]]
         )
 
+    def test_obj_subquery_lookup(self):
+        qs = JSONModel.objects.annotate(
+            value=Subquery(JSONModel.objects.filter(pk=OuterRef('pk')).values('field')),
+        ).filter(value__a='b')
+        self.assertSequenceEqual(qs, [self.objs[7], self.objs[8]])
+
     def test_deep_lookup_objs(self):
         self.assertSequenceEqual(
             JSONModel.objects.filter(field__k__l='m'),