Tested the case when the lhs of a raster lookup has an index specified and the rhs doesn't.

tests/gis_tests/rasterapp/test_rasterfield.py

@@ -7,8 +7,10 @@ from django.contrib.gis.gdal import GDALRaster
 from django.contrib.gis.geos import GEOSGeometry
 from django.contrib.gis.measure import D
 from django.contrib.gis.shortcuts import numpy
+from django.db import connection
 from django.db.models import Q
 from django.test import TransactionTestCase, skipUnlessDBFeature
+from django.test.utils import CaptureQueriesContext
 
 from ..data.rasters.textrasters import JSON_RASTER
 from .models import RasterModel, RasterRelatedModel
@@ -356,3 +358,10 @@ class RasterFieldTest(TransactionTestCase):
         msg = "Distance function requires a GeometryField in position 1, got RasterField."
         with self.assertRaisesMessage(TypeError, msg):
             RasterModel.objects.annotate(distance_from_point=Distance("rastprojected", point)).count()
+
+    def test_lhs_with_index_rhs_without_index(self):
+        with CaptureQueriesContext(connection) as queries:
+            RasterModel.objects.filter(rast__0__contains=json.loads(JSON_RASTER)).exists()
+        # It's easier to check the indexes in the generated SQL than to write
+        # tests that cover all index combinations.
+        self.assertRegex(queries[-1]['sql'], r'WHERE ST_Contains\([^)]*, 1, [^)]*, 1\)')