From da0fb5b1ec89a747459ab64482f3202cb452c068 Mon Sep 17 00:00:00 2001
From: Fabian Schindler <fabian.schindler.strauss@gmail.com>
Date: Mon, 10 Jul 2017 16:53:29 +0200
Subject: [PATCH] Fixed #28380 -- Excluded null geometries in SpatiaLite
 geometry lookups.

---
 .../gis/db/backends/spatialite/operations.py  | 28 +++++++++++--------
 tests/gis_tests/geoapp/tests.py               | 21 ++++++++++++++
 2 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/django/contrib/gis/db/backends/spatialite/operations.py b/django/contrib/gis/db/backends/spatialite/operations.py
index 449e6dcacf..0b5911c83d 100644
--- a/django/contrib/gis/db/backends/spatialite/operations.py
+++ b/django/contrib/gis/db/backends/spatialite/operations.py
@@ -17,6 +17,12 @@ from django.utils.functional import cached_property
 from django.utils.version import get_version_tuple
 
 
+class SpatialiteNullCheckOperator(SpatialOperator):
+    def as_sql(self, connection, lookup, template_params, sql_params):
+        sql, params = super().as_sql(connection, lookup, template_params, sql_params)
+        return '%s > 0' % sql, params
+
+
 class SpatiaLiteOperations(BaseSpatialOperations, DatabaseOperations):
     name = 'spatialite'
     spatialite = True
@@ -33,15 +39,15 @@ class SpatiaLiteOperations(BaseSpatialOperations, DatabaseOperations):
 
     gis_operators = {
         # Binary predicates
-        'equals': SpatialOperator(func='Equals'),
-        'disjoint': SpatialOperator(func='Disjoint'),
-        'touches': SpatialOperator(func='Touches'),
-        'crosses': SpatialOperator(func='Crosses'),
-        'within': SpatialOperator(func='Within'),
-        'overlaps': SpatialOperator(func='Overlaps'),
-        'contains': SpatialOperator(func='Contains'),
-        'intersects': SpatialOperator(func='Intersects'),
-        'relate': SpatialOperator(func='Relate'),
+        'equals': SpatialiteNullCheckOperator(func='Equals'),
+        'disjoint': SpatialiteNullCheckOperator(func='Disjoint'),
+        'touches': SpatialiteNullCheckOperator(func='Touches'),
+        'crosses': SpatialiteNullCheckOperator(func='Crosses'),
+        'within': SpatialiteNullCheckOperator(func='Within'),
+        'overlaps': SpatialiteNullCheckOperator(func='Overlaps'),
+        'contains': SpatialiteNullCheckOperator(func='Contains'),
+        'intersects': SpatialiteNullCheckOperator(func='Intersects'),
+        'relate': SpatialiteNullCheckOperator(func='Relate'),
         # Returns true if B's bounding box completely contains A's bounding box.
         'contained': SpatialOperator(func='MbrWithin'),
         # Returns true if A's bounding box completely contains B's bounding box.
@@ -49,8 +55,8 @@ class SpatiaLiteOperations(BaseSpatialOperations, DatabaseOperations):
         # Returns true if A's bounding box overlaps B's bounding box.
         'bboverlaps': SpatialOperator(func='MbrOverlaps'),
         # These are implemented here as synonyms for Equals
-        'same_as': SpatialOperator(func='Equals'),
-        'exact': SpatialOperator(func='Equals'),
+        'same_as': SpatialiteNullCheckOperator(func='Equals'),
+        'exact': SpatialiteNullCheckOperator(func='Equals'),
         # Distance predicates
         'dwithin': SpatialOperator(func='PtDistWithin'),
     }
diff --git a/tests/gis_tests/geoapp/tests.py b/tests/gis_tests/geoapp/tests.py
index 18bd42368a..f9838b461b 100644
--- a/tests/gis_tests/geoapp/tests.py
+++ b/tests/gis_tests/geoapp/tests.py
@@ -403,6 +403,27 @@ class GeoLookupTest(TestCase):
         State.objects.filter(name='Northern Mariana Islands').update(poly=None)
         self.assertIsNone(State.objects.get(name='Northern Mariana Islands').poly)
 
+    @skipUnlessDBFeature('supports_null_geometries', 'supports_crosses_lookup', 'supports_relate_lookup')
+    def test_null_geometries_excluded_in_lookups(self):
+        """NULL features are excluded in spatial lookup functions."""
+        null = State.objects.create(name='NULL', poly=None)
+        queries = [
+            ('equals', Point(1, 1)),
+            ('disjoint', Point(1, 1)),
+            ('touches', Point(1, 1)),
+            ('crosses', LineString((0, 0), (1, 1), (5, 5))),
+            ('within', Point(1, 1)),
+            ('overlaps', LineString((0, 0), (1, 1), (5, 5))),
+            ('contains', LineString((0, 0), (1, 1), (5, 5))),
+            ('intersects', LineString((0, 0), (1, 1), (5, 5))),
+            ('relate', (Point(1, 1), 'T*T***FF*')),
+            ('same_as', Point(1, 1)),
+            ('exact', Point(1, 1)),
+        ]
+        for lookup, geom in queries:
+            with self.subTest(lookup=lookup):
+                self.assertNotIn(null, State.objects.filter(**{'poly__%s' % lookup: geom}))
+
     @skipUnlessDBFeature("supports_relate_lookup")
     def test_relate_lookup(self):
         "Testing the 'relate' lookup type."