[2.2.x] Fixed #30672 -- Fixed crash of JSONField/HStoreField key transforms on expressions with params.

Regression in 4f5b58f5cd3c57fee9972ab074f8dc6895d8f387.

Thanks Florian Apolloner for the report and helping with tests.

Backport of 1f8382d34d54061eddc41df6994e20ee38c60907 from master.

django/contrib/postgres/fields/hstore.py

@@ -86,7 +86,7 @@ class KeyTransform(Transform):
 
     def as_sql(self, compiler, connection):
         lhs, params = compiler.compile(self.lhs)
-        return '(%s -> %%s)' % lhs, [self.key_name] + params
+        return '(%s -> %%s)' % lhs, params + [self.key_name]
 
 
 class KeyTransformFactory:

django/contrib/postgres/fields/jsonb.py

@@ -112,7 +112,7 @@ class KeyTransform(Transform):
             lookup = int(self.key_name)
         except ValueError:
             lookup = self.key_name
-        return '(%s %s %%s)' % (lhs, self.operator), [lookup] + params
+        return '(%s %s %%s)' % (lhs, self.operator), params + [lookup]
 
 
 class KeyTextTransform(KeyTransform):

docs/releases/1.11.24.txt

@@ -0,0 +1,15 @@
+============================
+Django 1.11.24 release notes
+============================
+
+*Expected September 2, 2019*
+
+Django 1.11.24 fixes a regression in 1.11.23.
+
+Bugfixes
+========
+
+* Fixed crash of ``KeyTransform()`` for
+  :class:`~django.contrib.postgres.fields.JSONField` and
+  :class:`~django.contrib.postgres.fields.HStoreField` when using on
+  expressions with params (:ticket:`30672`).

docs/releases/2.1.12.txt

@@ -0,0 +1,15 @@
+===========================
+Django 2.1.12 release notes
+===========================
+
+*Expected September 2, 2019*
+
+Django 2.1.12 fixes a regression in 2.1.11.
+
+Bugfixes
+========
+
+* Fixed crash of ``KeyTransform()`` for
+  :class:`~django.contrib.postgres.fields.JSONField` and
+  :class:`~django.contrib.postgres.fields.HStoreField` when using on
+  expressions with params (:ticket:`30672`).

docs/releases/2.2.5.txt

@@ -12,3 +12,8 @@ Bugfixes
 * Relaxed the system check added in Django 2.2 for models to reallow use of the
   same ``db_table`` by multiple models when database routers are installed
   (:ticket:`30673`).
+
+* Fixed crash of ``KeyTransform()`` for
+  :class:`~django.contrib.postgres.fields.JSONField` and
+  :class:`~django.contrib.postgres.fields.HStoreField` when using on
+  expressions with params (:ticket:`30672`).

docs/releases/index.txt

@@ -37,6 +37,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   2.1.12
    2.1.11
    2.1.10
    2.1.9
@@ -75,6 +76,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   1.11.24
    1.11.23
    1.11.22
    1.11.21

tests/postgres_tests/test_hstore.py

@@ -2,6 +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.forms import Form
 from django.test.utils import CaptureQueriesContext, isolate_apps
 
@@ -11,6 +12,7 @@ from .models import HStoreModel, PostgreSQLModel
 try:
     from django.contrib.postgres import forms
     from django.contrib.postgres.fields import HStoreField
+    from django.contrib.postgres.fields.hstore import KeyTransform
     from django.contrib.postgres.validators import KeysValidator
 except ImportError:
     pass
@@ -127,6 +129,13 @@ class TestQuerying(PostgreSQLTestCase):
             self.objs[:2]
         )
 
+    def test_key_transform_raw_expression(self):
+        expr = RawSQL('%s::hstore', ['x => b, y => c'])
+        self.assertSequenceEqual(
+            HStoreModel.objects.filter(field__a=KeyTransform('x', expr)),
+            self.objs[:2]
+        )
+
     def test_keys(self):
         self.assertSequenceEqual(
             HStoreModel.objects.filter(field__keys=['a']),

tests/postgres_tests/test_json.py

@@ -6,7 +6,9 @@ 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, Q
+from django.db.models import Count, F, Q
+from django.db.models.expressions import RawSQL
+from django.db.models.functions import Cast
 from django.forms import CharField, Form, widgets
 from django.test.utils import CaptureQueriesContext, isolate_apps
 from django.utils.html import escape
@@ -177,6 +179,23 @@ class TestQuerying(PostgreSQLTestCase):
             operator.itemgetter('key', 'count'),
         )
 
+    def test_key_transform_raw_expression(self):
+        expr = RawSQL('%s::jsonb', ['{"x": "bar"}'])
+        self.assertSequenceEqual(
+            JSONModel.objects.filter(field__foo=KeyTransform('x', expr)),
+            [self.objs[-1]],
+        )
+
+    def test_key_transform_expression(self):
+        self.assertSequenceEqual(
+            JSONModel.objects.filter(field__d__0__isnull=False).annotate(
+                key=KeyTransform('d', 'field'),
+                chain=KeyTransform('0', 'key'),
+                expr=KeyTransform('0', Cast('key', JSONField())),
+            ).filter(chain=F('expr')),
+            [self.objs[8]],
+        )
+
     def test_deep_values(self):
         query = JSONModel.objects.values_list('field__k__l')
         self.assertSequenceEqual(