Fixed #28353 -- Fixed some GIS functions when queryset is evaluated more than once.

Reverted test for refs #27603 in favor of using FuncTestMixin.

7 files changed, 104 insertions, 13 deletions

diff --git a/tests/gis_tests/distapp/tests.py b/tests/gis_tests/distapp/tests.py
index 395f7226ef..d162759513 100644
--- a/tests/gis_tests/distapp/tests.py
+++ b/tests/gis_tests/distapp/tests.py
@@ -9,7 +9,9 @@ from django.db import connection
 from django.db.models import F, Q
 from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
 
-from ..utils import mysql, no_oracle, oracle, postgis, spatialite
+from ..utils import (
+    FuncTestMixin, mysql, no_oracle, oracle, postgis, spatialite,
+)
 from .models import (
     AustraliaCity, CensusZipcode, Interstate, SouthTexasCity, SouthTexasCityFt,
     SouthTexasInterstate, SouthTexasZipcode,
@@ -262,7 +264,7 @@ Perimeter(geom1)                                |    OK              |      :-(
 '''  # NOQA
 
 
-class DistanceFunctionsTests(TestCase):
+class DistanceFunctionsTests(FuncTestMixin, TestCase):
     fixtures = ['initial']
 
     @skipUnlessDBFeature("has_Area_function")
diff --git a/tests/gis_tests/geo3d/tests.py b/tests/gis_tests/geo3d/tests.py
index 39603d1249..d2e85f0607 100644
--- a/tests/gis_tests/geo3d/tests.py
+++ b/tests/gis_tests/geo3d/tests.py
@@ -8,6 +8,7 @@ from django.contrib.gis.db.models.functions import (
 from django.contrib.gis.geos import GEOSGeometry, LineString, Point, Polygon
 from django.test import TestCase, skipUnlessDBFeature
 
+from ..utils import FuncTestMixin
 from .models import (
     City3D, Interstate2D, Interstate3D, InterstateProj2D, InterstateProj3D,
     MultiPoint3D, Point2D, Point3D, Polygon2D, Polygon3D,
@@ -205,7 +206,7 @@ class Geo3DTest(Geo3DLoadingHelper, TestCase):
 
 
 @skipUnlessDBFeature("supports_3d_functions")
-class Geo3DFunctionsTests(Geo3DLoadingHelper, TestCase):
+class Geo3DFunctionsTests(FuncTestMixin, Geo3DLoadingHelper, TestCase):
     def test_kml(self):
         """
         Test KML() function with Z values.
diff --git a/tests/gis_tests/geoapp/test_functions.py b/tests/gis_tests/geoapp/test_functions.py
index bb13d9e37f..cdd05d78ff 100644
--- a/tests/gis_tests/geoapp/test_functions.py
+++ b/tests/gis_tests/geoapp/test_functions.py
@@ -12,11 +12,11 @@ from django.db import connection
 from django.db.models import Sum
 from django.test import TestCase, skipUnlessDBFeature
 
-from ..utils import mysql, oracle, postgis, spatialite
+from ..utils import FuncTestMixin, mysql, oracle, postgis, spatialite
 from .models import City, Country, CountryWebMercator, State, Track
 
 
-class GISFunctionsTests(TestCase):
+class GISFunctionsTests(FuncTestMixin, TestCase):
     """
     Testing functions from django/contrib/gis/db/models/functions.py.
     Area/Distance/Length/Perimeter are tested in distapp/tests.
@@ -127,11 +127,8 @@ class GISFunctionsTests(TestCase):
             City.objects.annotate(kml=functions.AsKML('name'))
 
         # Ensuring the KML is as expected.
-        qs = City.objects.annotate(kml=functions.AsKML('point', precision=9))
-        ptown = qs.get(name='Pueblo')
+        ptown = City.objects.annotate(kml=functions.AsKML('point', precision=9)).get(name='Pueblo')
         self.assertEqual('<Point><coordinates>-104.609252,38.255001</coordinates></Point>', ptown.kml)
-        # Same result if the queryset is evaluated again.
-        self.assertEqual(qs.get(name='Pueblo').kml, ptown.kml)
 
     @skipUnlessDBFeature("has_AsSVG_function")
     def test_assvg(self):
diff --git a/tests/gis_tests/geogapp/tests.py b/tests/gis_tests/geogapp/tests.py
index 2969ca1cc6..c9986fd78b 100644
--- a/tests/gis_tests/geogapp/tests.py
+++ b/tests/gis_tests/geogapp/tests.py
@@ -11,7 +11,7 @@ from django.db import connection
 from django.db.models.functions import Cast
 from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
 
-from ..utils import oracle, postgis, spatialite
+from ..utils import FuncTestMixin, oracle, postgis, spatialite
 from .models import City, County, Zipcode
 
 
@@ -86,7 +86,7 @@ class GeographyTest(TestCase):
             self.assertEqual(state, c.state)
 
 
-class GeographyFunctionTests(TestCase):
+class GeographyFunctionTests(FuncTestMixin, TestCase):
     fixtures = ['initial']
 
     @skipUnlessDBFeature("supports_extent_aggr")
diff --git a/tests/gis_tests/test_fields.py b/tests/gis_tests/test_fields.py
index fb0c953f21..27db3e1dfa 100644
--- a/tests/gis_tests/test_fields.py
+++ b/tests/gis_tests/test_fields.py
@@ -7,9 +7,9 @@ from django.test import SimpleTestCase
 class FieldsTests(SimpleTestCase):
 
     def test_area_field_deepcopy(self):
-        field = AreaField()
+        field = AreaField(None)
         self.assertEqual(copy.deepcopy(field), field)
 
     def test_distance_field_deepcopy(self):
-        field = DistanceField()
+        field = DistanceField(None)
         self.assertEqual(copy.deepcopy(field), field)
diff --git a/tests/gis_tests/test_gis_tests_utils.py b/tests/gis_tests/test_gis_tests_utils.py
new file mode 100644
index 0000000000..32d072fd9b
--- /dev/null
+++ b/tests/gis_tests/test_gis_tests_utils.py
@@ -0,0 +1,52 @@
+from django.db import connection, models
+from django.db.models.expressions import Func
+from django.test import SimpleTestCase
+
+from .utils import FuncTestMixin
+
+
+def test_mutation(raises=True):
+    def wrapper(mutation_func):
+        def test(test_case_instance, *args, **kwargs):
+            class TestFunc(Func):
+                output_field = models.IntegerField()
+
+                def __init__(self):
+                    self.attribute = 'initial'
+                    super().__init__('initial', ['initial'])
+
+                def as_sql(self, *args, **kwargs):
+                    mutation_func(self)
+                    return '', ()
+
+            if raises:
+                msg = 'TestFunc Func was mutated during compilation.'
+                with test_case_instance.assertRaisesMessage(AssertionError, msg):
+                    getattr(TestFunc(), 'as_' + connection.vendor)(None, None)
+            else:
+                getattr(TestFunc(), 'as_' + connection.vendor)(None, None)
+
+        return test
+    return wrapper
+
+
+class FuncTestMixinTests(FuncTestMixin, SimpleTestCase):
+    @test_mutation()
+    def test_mutated_attribute(func):
+        func.attribute = 'mutated'
+
+    @test_mutation()
+    def test_mutated_expressions(func):
+        func.source_expressions.clear()
+
+    @test_mutation()
+    def test_mutated_expression(func):
+        func.source_expressions[0].name = 'mutated'
+
+    @test_mutation()
+    def test_mutated_expression_deep(func):
+        func.source_expressions[1].value[0] = 'mutated'
+
+    @test_mutation(raises=False)
+    def test_not_mutated(func):
+        pass
diff --git a/tests/gis_tests/utils.py b/tests/gis_tests/utils.py
index 6eb029c1d5..b30da7e40d 100644
--- a/tests/gis_tests/utils.py
+++ b/tests/gis_tests/utils.py
@@ -1,8 +1,11 @@
+import copy
 import unittest
 from functools import wraps
+from unittest import mock
 
 from django.conf import settings
 from django.db import DEFAULT_DB_ALIAS, connection
+from django.db.models.expressions import Func
 
 
 def skipUnlessGISLookup(*gis_lookups):
@@ -56,3 +59,39 @@ elif spatialite:
     from django.contrib.gis.db.backends.spatialite.models import SpatialiteSpatialRefSys as SpatialRefSys
 else:
     SpatialRefSys = None
+
+
+class FuncTestMixin:
+    """Assert that Func expressions aren't mutated during their as_sql()."""
+    def setUp(self):
+        def as_sql_wrapper(original_as_sql):
+            def inner(*args, **kwargs):
+                func = original_as_sql.__self__
+                # Resolve output_field before as_sql() so touching it in
+                # as_sql() won't change __dict__.
+                func.output_field
+                __dict__original = copy.deepcopy(func.__dict__)
+                result = original_as_sql(*args, **kwargs)
+                msg = '%s Func was mutated during compilation.' % func.__class__.__name__
+                self.assertEqual(func.__dict__, __dict__original, msg)
+                return result
+            return inner
+
+        def __getattribute__(self, name):
+            if name != vendor_impl:
+                return __getattribute__original(self, name)
+            try:
+                as_sql = __getattribute__original(self, vendor_impl)
+            except AttributeError:
+                as_sql = __getattribute__original(self, 'as_sql')
+            return as_sql_wrapper(as_sql)
+
+        vendor_impl = 'as_' + connection.vendor
+        __getattribute__original = Func.__getattribute__
+        self.func_patcher = mock.patch.object(Func, '__getattribute__', __getattribute__)
+        self.func_patcher.start()
+        super().setUp()
+
+    def tearDown(self):
+        super().tearDown()
+        self.func_patcher.stop()