Fixed #27448 -- Switched use of functions deprecated in PostGIS 2.2.

Thanks Claude Paroz and Tim Graham for reviews, and
Mjumbe Wawatu Poe for the initial regression test.

django/contrib/gis/db/backends/postgis/operations.py

@@ -91,13 +91,16 @@ class PostGISDistanceOperator(PostGISOperator):
             template_params = self.check_raster(lookup, template_params)
             sql_template = self.sql_template
             if len(lookup.rhs) == 3 and lookup.rhs[-1] == 'spheroid':
-                template_params.update({'op': self.op, 'func': 'ST_Distance_Spheroid'})
+                template_params.update({
+                    'op': self.op,
+                    'func': connection.ops.spatial_function_name('DistanceSpheroid'),
+                })
                 sql_template = '%(func)s(%(lhs)s, %(rhs)s, %%s) %(op)s %(value)s'
-                # Using distance_spheroid requires the spheroid of the field as
+                # Using DistanceSpheroid requires the spheroid of the field as
                 # a parameter.
                 sql_params.insert(1, lookup.lhs.output_field._spheroid)
             else:
-                template_params.update({'op': self.op, 'func': 'ST_Distance_Sphere'})
+                template_params.update({'op': self.op, 'func': connection.ops.spatial_function_name('DistanceSphere')})
             return sql_template % template_params, sql_params
         return super(PostGISDistanceOperator, self).as_sql(connection, lookup, template_params, sql_params)
 
@@ -146,11 +149,6 @@ class PostGISOperations(BaseSpatialOperations, DatabaseOperations):
     }
 
     unsupported_functions = set()
-    function_names = {
-        'BoundingCircle': 'ST_MinimumBoundingCircle',
-        'MemSize': 'ST_Mem_Size',
-        'NumPoints': 'ST_NPoints',
-    }
 
     def __init__(self, connection):
         super(PostGISOperations, self).__init__(connection)
@@ -197,6 +195,21 @@ class PostGISOperations(BaseSpatialOperations, DatabaseOperations):
         self.union = prefix + 'Union'
         self.unionagg = prefix + 'Union'
 
+    @cached_property
+    def function_names(self):
+        function_names = {
+            'BoundingCircle': 'ST_MinimumBoundingCircle',
+            'NumPoints': 'ST_NPoints',
+        }
+        if self.spatial_version < (2, 2, 0):
+            function_names.update({
+                'DistanceSphere': 'ST_distance_sphere',
+                'DistanceSpheroid': 'ST_distance_spheroid',
+                'LengthSpheroid': 'ST_length_spheroid',
+                'MemSize': 'ST_mem_size',
+            })
+        return function_names
+
     @cached_property
     def spatial_version(self):
         """Determine the version of the PostGIS library."""

django/contrib/gis/db/models/functions.py

@@ -249,11 +249,12 @@ class Distance(DistanceResultMixin, OracleToleranceMixin, GeoFuncWithGeoParam):
         elif geo_field.geodetic(connection):
             # Geometry fields with geodetic (lon/lat) coordinates need special distance functions
             if self.spheroid:
-                self.function = 'ST_Distance_Spheroid'  # More accurate, resource intensive
+                # DistanceSpheroid is more accurate and resource intensive than DistanceSphere
+                self.function = connection.ops.spatial_function_name('DistanceSpheroid')
                 # Replace boolean param by the real spheroid of the base field
                 self.source_expressions[2] = Value(geo_field._spheroid)
             else:
-                self.function = 'ST_Distance_Sphere'
+                self.function = connection.ops.spatial_function_name('DistanceSphere')
         return super(Distance, self).as_sql(compiler, connection)
 
     def as_oracle(self, compiler, connection):
@@ -307,7 +308,7 @@ class Length(DistanceResultMixin, OracleToleranceMixin, GeoFunc):
             self.source_expressions.append(Value(self.spheroid))
         elif geo_field.geodetic(connection):
             # Geometry fields with geodetic (lon/lat) coordinates need length_spheroid
-            self.function = 'ST_Length_Spheroid'
+            self.function = connection.ops.spatial_function_name('LengthSpheroid')
             self.source_expressions.append(Value(geo_field._spheroid))
         else:
             dim = min(f.dim for f in self.get_source_fields() if f)

tests/gis_tests/tests.py

@@ -94,3 +94,21 @@ class TestPostGISVersionCheck(unittest.TestCase):
         ops = FakePostGISOperations()
         with self.assertRaises(ImproperlyConfigured):
             ops.spatial_version
+
+    def test_version_dependent_funcs(self):
+        """
+        Resolve names of functions renamed and deprecated in PostGIS 2.2.0
+        depending on PostGIS version.
+        Remove when dropping support for PostGIS 2.1.
+        """
+        ops = FakePostGISOperations('2.2.0')
+        self.assertEqual(ops.spatial_function_name('DistanceSphere'), 'ST_DistanceSphere')
+        self.assertEqual(ops.spatial_function_name('DistanceSpheroid'), 'ST_DistanceSpheroid')
+        self.assertEqual(ops.spatial_function_name('LengthSpheroid'), 'ST_LengthSpheroid')
+        self.assertEqual(ops.spatial_function_name('MemSize'), 'ST_MemSize')
+
+        ops = FakePostGISOperations('2.1.0')
+        self.assertEqual(ops.spatial_function_name('DistanceSphere'), 'ST_distance_sphere')
+        self.assertEqual(ops.spatial_function_name('DistanceSpheroid'), 'ST_distance_spheroid')
+        self.assertEqual(ops.spatial_function_name('LengthSpheroid'), 'ST_length_spheroid')
+        self.assertEqual(ops.spatial_function_name('MemSize'), 'ST_mem_size')