Fixed #25708 -- Fixed annotations with geometry values.

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

@@ -312,6 +312,12 @@ class GeometryField(GeoSelectFormatMixin, BaseSpatialField):
         """
         return connection.ops.get_distance(self, value, lookup_type)
 
+    def get_db_prep_value(self, value, connection, *args, **kwargs):
+        return connection.ops.Adapter(
+            super(GeometryField, self).get_db_prep_value(value, connection, *args, **kwargs),
+            **({'geography': True} if self.geography else {})
+        )
+
     def from_db_value(self, value, expression, connection, context):
         if value:
             if not isinstance(value, Geometry):

django/db/models/expressions.py

@@ -579,6 +579,8 @@ class Value(Expression):
                 val = self.output_field.get_db_prep_save(val, connection=connection)
             else:
                 val = self.output_field.get_db_prep_value(val, connection=connection)
+            if hasattr(self._output_field, 'get_placeholder'):
+                return self._output_field.get_placeholder(val, compiler, connection), [val]
         if val is None:
             # cx_Oracle does not always convert None to the appropriate
             # NULL type (like in case expressions using numbers), so we

tests/gis_tests/geoapp/test_expressions.py

+from unittest import skipUnless
+
+from django.contrib.gis.db.models import GeometryField, Value, functions
+from django.contrib.gis.geos import Point, Polygon
+from django.test import TestCase, skipUnlessDBFeature
+
+from ..utils import postgis
+from .models import City
+
+
+@skipUnlessDBFeature('gis_enabled')
+class GeoExpressionsTests(TestCase):
+    fixtures = ['initial']
+
+    def test_geometry_value_annotation(self):
+        p = Point(1, 1, srid=4326)
+        point = City.objects.annotate(p=Value(p, GeometryField(srid=4326))).first().p
+        self.assertEqual(point, p)
+
+    @skipUnlessDBFeature('supports_transform')
+    def test_geometry_value_annotation_different_srid(self):
+        p = Point(1, 1, srid=32140)
+        point = City.objects.annotate(p=Value(p, GeometryField(srid=4326))).first().p
+        self.assertTrue(point.equals_exact(p.transform(4326, clone=True), 10 ** -5))
+        self.assertEqual(point.srid, 4326)
+
+    @skipUnless(postgis, 'Only postgis has geography fields.')
+    def test_geography_value(self):
+        p = Polygon(((1, 1), (1, 2), (2, 2), (2, 1), (1, 1)))
+        area = City.objects.annotate(a=functions.Area(Value(p, GeometryField(srid=4326, geography=True)))).first().a
+        self.assertAlmostEqual(area.sq_km, 12305.1, 0)