Fixed #26455 -- Allowed filtering and repairing invalid geometries.

Added the IsValid and MakeValid database functions, and the isvalid lookup,
all for PostGIS.

Thanks Tim Graham for the review.

django/contrib/gis/db/backends/base/features.py

@@ -64,6 +64,10 @@ class BaseSpatialFeatures(object):
     def supports_relate_lookup(self):
         return 'relate' in self.connection.ops.gis_operators
 
+    @property
+    def supports_isvalid_lookup(self):
+        return 'isvalid' in self.connection.ops.gis_operators
+
     # For each of those methods, the class will have a property named
     # `has_<name>_method` (defined in __init__) which accesses connection.ops
     # to determine GIS method availability.

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

@@ -58,10 +58,10 @@ class BaseSpatialOperations(object):
     unsupported_functions = {
         'Area', 'AsGeoJSON', 'AsGML', 'AsKML', 'AsSVG',
         'BoundingCircle', 'Centroid', 'Difference', 'Distance', 'Envelope',
-        'ForceRHR', 'GeoHash', 'Intersection', 'Length', 'MemSize', 'NumGeometries',
-        'NumPoints', 'Perimeter', 'PointOnSurface', 'Reverse', 'Scale',
-        'SnapToGrid', 'SymDifference', 'Transform', 'Translate',
-        'Union',
+        'ForceRHR', 'GeoHash', 'Intersection', 'IsValid', 'Length', 'MakeValid',
+        'MemSize', 'NumGeometries', 'NumPoints', 'Perimeter', 'PointOnSurface',
+        'Reverse', 'Scale', 'SnapToGrid', 'SymDifference', 'Transform',
+        'Translate', 'Union',
     }
 
     # Serialization

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

@@ -67,7 +67,7 @@ class MySQLOperations(BaseSpatialOperations, DatabaseOperations):
     def unsupported_functions(self):
         unsupported = {
             'AsGeoJSON', 'AsGML', 'AsKML', 'AsSVG', 'BoundingCircle',
-            'ForceRHR', 'GeoHash', 'MemSize',
+            'ForceRHR', 'GeoHash', 'IsValid', 'MakeValid', 'MemSize',
             'Perimeter', 'PointOnSurface', 'Reverse', 'Scale', 'SnapToGrid',
             'Transform', 'Translate',
         }

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

@@ -127,7 +127,7 @@ class OracleOperations(BaseSpatialOperations, DatabaseOperations):
     unsupported_functions = {
         'AsGeoJSON', 'AsGML', 'AsKML', 'AsSVG',
         'BoundingCircle', 'Envelope',
-        'ForceRHR', 'GeoHash', 'MemSize', 'Scale',
+        'ForceRHR', 'GeoHash', 'IsValid', 'MakeValid', 'MemSize', 'Scale',
         'SnapToGrid', 'Translate',
     }
 

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

@@ -79,6 +79,7 @@ class PostGISOperations(BaseSpatialOperations, DatabaseOperations):
         'disjoint': PostGISOperator(func='ST_Disjoint'),
         'equals': PostGISOperator(func='ST_Equals'),
         'intersects': PostGISOperator(func='ST_Intersects', geography=True),
+        'isvalid': PostGISOperator(func='ST_IsValid'),
         'overlaps': PostGISOperator(func='ST_Overlaps'),
         'relate': PostGISOperator(func='ST_Relate'),
         'touches': PostGISOperator(func='ST_Touches'),
@@ -118,11 +119,13 @@ class PostGISOperations(BaseSpatialOperations, DatabaseOperations):
         self.geojson = prefix + 'AsGeoJson'
         self.gml = prefix + 'AsGML'
         self.intersection = prefix + 'Intersection'
+        self.isvalid = prefix + 'IsValid'
         self.kml = prefix + 'AsKML'
         self.length = prefix + 'Length'
         self.length3d = prefix + '3DLength'
         self.length_spheroid = prefix + 'length_spheroid'
         self.makeline = prefix + 'MakeLine'
+        self.makevalid = prefix + 'MakeValid'
         self.mem_size = prefix + 'mem_size'
         self.num_geom = prefix + 'NumGeometries'
         self.num_points = prefix + 'npoints'

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

@@ -96,7 +96,7 @@ class SpatiaLiteOperations(BaseSpatialOperations, DatabaseOperations):
 
     @cached_property
     def unsupported_functions(self):
-        unsupported = {'BoundingCircle', 'ForceRHR', 'MemSize'}
+        unsupported = {'BoundingCircle', 'ForceRHR', 'IsValid', 'MakeValid', 'MemSize'}
         if self.spatial_version < (3, 1, 0):
             unsupported.add('SnapToGrid')
         if self.spatial_version < (4, 0, 0):

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

@@ -225,7 +225,7 @@ class GeometryField(GeoSelectFormatMixin, BaseSpatialField):
         returning to the caller.
         """
         value = super(GeometryField, self).get_prep_value(value)
-        if isinstance(value, Expression):
+        if isinstance(value, (Expression, bool)):
             return value
         elif isinstance(value, (tuple, list)):
             geom = value[0]

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

@@ -6,7 +6,7 @@ from django.contrib.gis.measure import (
     Area as AreaMeasure, Distance as DistanceMeasure,
 )
 from django.core.exceptions import FieldError
-from django.db.models import FloatField, IntegerField, TextField
+from django.db.models import BooleanField, FloatField, IntegerField, TextField
 from django.db.models.expressions import Func, Value
 from django.utils import six
 
@@ -282,6 +282,10 @@ class Intersection(OracleToleranceMixin, GeoFuncWithGeoParam):
     arity = 2
 
 
+class IsValid(GeoFunc):
+    output_field_class = BooleanField
+
+
 class Length(DistanceResultMixin, OracleToleranceMixin, GeoFunc):
     output_field_class = FloatField
 
@@ -319,6 +323,10 @@ class Length(DistanceResultMixin, OracleToleranceMixin, GeoFunc):
         return super(Length, self).as_sql(compiler, connection)
 
 
+class MakeValid(GeoFunc):
+    pass
+
+
 class MemSize(GeoFunc):
     output_field_class = IntegerField
     arity = 1

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

@@ -5,7 +5,7 @@ import re
 from django.core.exceptions import FieldDoesNotExist
 from django.db.models.constants import LOOKUP_SEP
 from django.db.models.expressions import Col, Expression
-from django.db.models.lookups import Lookup
+from django.db.models.lookups import BuiltinLookup, Lookup
 from django.utils import six
 
 gis_lookups = {}
@@ -270,6 +270,19 @@ class IntersectsLookup(GISLookup):
 gis_lookups['intersects'] = IntersectsLookup
 
 
+class IsValidLookup(BuiltinLookup):
+    lookup_name = 'isvalid'
+
+    def as_sql(self, compiler, connection):
+        gis_op = connection.ops.gis_operators[self.lookup_name]
+        sql, params = self.process_lhs(compiler, connection)
+        sql = '%(func)s(%(lhs)s)' % {'func': gis_op.func, 'lhs': sql}
+        if not self.rhs:
+            sql = 'NOT ' + sql
+        return sql, params
+gis_lookups['isvalid'] = IsValidLookup
+
+
 class OverlapsLookup(GISLookup):
     lookup_name = 'overlaps'
 gis_lookups['overlaps'] = OverlapsLookup