Fixed #25141 -- Diminished GDAL dependence during geojson serialization

Only require GDAL if contained geometries need coordinate transformations.
Thanks drepo for the report and Tim Graham for the review.

1 files changed, 10 insertions, 1 deletions

diff --git a/tests/gis_tests/geoapp/test_serializers.py b/tests/gis_tests/geoapp/test_serializers.py
index 09f837417b..1bf3ec0acf 100644
--- a/tests/gis_tests/geoapp/test_serializers.py
+++ b/tests/gis_tests/geoapp/test_serializers.py
@@ -4,7 +4,8 @@ import json
 
 from django.contrib.gis.geos import LinearRing, Point, Polygon
 from django.core import serializers
-from django.test import TestCase, skipUnlessDBFeature
+from django.test import TestCase, mock, skipUnlessDBFeature
+from django.utils import six
 
 from .models import City, MultiFields, PennsylvaniaCity
 
@@ -70,6 +71,14 @@ class GeoJSONSerializerTests(TestCase):
             [int(c) for c in geodata['features'][0]['geometry']['coordinates']],
             [1564802, 5613214])
 
+    @mock.patch('django.contrib.gis.serializers.geojson.HAS_GDAL', False)
+    def test_without_gdal(self):
+        # Without coordinate transformation, the serialization should succeed:
+        serializers.serialize('geojson', City.objects.all())
+        with six.assertRaisesRegex(self, serializers.base.SerializationError, '.*GDAL is not installed'):
+            # Coordinate transformations need GDAL
+            serializers.serialize('geojson', City.objects.all(), srid=2847)
+
     def test_deserialization_exception(self):
         """
         GeoJSON cannot be deserialized.