[2.2.x] Fixed #30335, #29139 -- Fixed crash when ordering or aggregat…

…ing over a nested JSONField key transform.

Backport of d87bd29 from master.

django/db/models/sql/compiler.py

@@ -17,6 +17,7 @@
 from django.utils.deprecation import (
     RemovedInDjango30Warning, RemovedInDjango31Warning,
 )
+from django.utils.hashable import make_hashable
 from django.utils.inspect import func_supports_parameter
 
 FORCE = object()
@@ -135,9 +136,10 @@ def get_group_by(self, select, order_by):
                 # wrapping () because they could be removed when a subquery is
                 # the "rhs" in an expression (see Subquery._prepare()).
                 sql = '(%s)' % sql
-            if (sql, tuple(params)) not in seen:
+            params_hash = make_hashable(params)
+            if (sql, params_hash) not in seen:
                 result.append((sql, params))
-                seen.add((sql, tuple(params)))
+                seen.add((sql, params_hash))
         return result
 
     def collapse_group_by(self, expressions, having):
@@ -361,9 +363,10 @@ def get_order_by(self):
             # is refactored into expressions, then we can check each part as we
             # generate it.
             without_ordering = self.ordering_parts.search(sql).group(1)
-            if (without_ordering, tuple(params)) in seen:
+            params_hash = make_hashable(params)
+            if (without_ordering, params_hash) in seen:
                 continue
-            seen.add((without_ordering, tuple(params)))
+            seen.add((without_ordering, params_hash))
             result.append((resolved, (sql, params, is_ref)))
         return result
 

docs/releases/2.2.1.txt

@@ -33,3 +33,8 @@ Bugfixes
 * Reverted an optimization in Django 2.2 (:ticket:`29725`) that caused the
   inconsistent behavior of ``count()`` and ``exists()`` on a reverse
   many-to-many relationship with a custom manager (:ticket:`30325`).
+
+* Fixed a regression in Django 2.2 where
+  :class:`~django.core.paginator.Paginator` crashed when ``object_list`` was
+  a queryset ordered or aggregated over a nested ``JSONField`` key transform
+  (:ticket:`30335`).

tests/postgres_tests/test_json.py

@@ -1,10 +1,11 @@
 import datetime
+import operator
 import uuid
 from decimal import Decimal
 
 from django.core import checks, exceptions, serializers
 from django.core.serializers.json import DjangoJSONEncoder
-from django.db.models import Q
+from django.db.models import Count, Q
 from django.forms import CharField, Form, widgets
 from django.test.utils import isolate_apps
 from django.utils.html import escape
@@ -15,6 +16,7 @@
 try:
     from django.contrib.postgres import forms
     from django.contrib.postgres.fields import JSONField
+    from django.contrib.postgres.fields.jsonb import KeyTextTransform, KeyTransform
 except ImportError:
     pass
 
@@ -153,6 +155,27 @@ def test_ordering_by_transform(self):
         query = JSONModel.objects.filter(field__name__isnull=False).order_by('field__ord')
         self.assertSequenceEqual(query, [objs[4], objs[2], objs[3], objs[1], objs[0]])
 
+    def test_ordering_grouping_by_key_transform(self):
+        base_qs = JSONModel.objects.filter(field__d__0__isnull=False)
+        for qs in (
+            base_qs.order_by('field__d__0'),
+            base_qs.annotate(key=KeyTransform('0', KeyTransform('d', 'field'))).order_by('key'),
+        ):
+            self.assertSequenceEqual(qs, [self.objs[8]])
+        qs = JSONModel.objects.filter(field__isnull=False)
+        self.assertQuerysetEqual(
+            qs.values('field__d__0').annotate(count=Count('field__d__0')).order_by('count'),
+            [1, 10],
+            operator.itemgetter('count'),
+        )
+        self.assertQuerysetEqual(
+            qs.filter(field__isnull=False).annotate(
+                key=KeyTextTransform('f', KeyTransform('1', KeyTransform('d', 'field'))),
+            ).values('key').annotate(count=Count('key')).order_by('count'),
+            [(None, 0), ('g', 1)],
+            operator.itemgetter('key', 'count'),
+        )
+
     def test_deep_values(self):
         query = JSONModel.objects.values_list('field__k__l')
         self.assertSequenceEqual(