Fixed #25865 -- Made OSMGeoAdmin to require GDAL only if transformation is really needed.

django/contrib/gis/admin/options.py

@@ -59,6 +59,11 @@ def formfield_for_dbfield(self, db_field, **kwargs):
         3D editing).
         """
         if isinstance(db_field, models.GeometryField) and db_field.dim < 3:
+            if not HAS_GDAL and db_field.srid != self.map_srid:
+                raise ImproperlyConfigured(
+                    "Map SRID is %s and SRID of `%s` is %s. "
+                    "GDAL should be installed to perform transformation." % (self.map_srid, db_field, db_field.srid)
+                )
             kwargs.pop('request', None)
             # Setting the widget with the newly defined widget.
             kwargs['widget'] = self.get_map_widget(db_field)
@@ -135,8 +140,3 @@ class OSMGeoAdmin(GeoModelAdmin):
     max_resolution = '156543.0339'
     point_zoom = num_zoom - 6
     units = 'm'
-
-    def __init__(self, *args):
-        if not HAS_GDAL:
-            raise ImproperlyConfigured("OSMGeoAdmin is not usable without GDAL libs installed")
-        super(OSMGeoAdmin, self).__init__(*args)

django/contrib/gis/geos/prototypes/io.py

@@ -54,6 +54,9 @@ class WKBWriter_st(Structure):
     'GEOSWKTWriter_setOutputDimension', argtypes=[WKT_WRITE_PTR, c_int]
 )
 
+wkt_writer_set_trim = GEOSFuncFactory('GEOSWKTWriter_setTrim', argtypes=[WKT_WRITE_PTR, c_char])
+wkt_writer_set_precision = GEOSFuncFactory('GEOSWKTWriter_setRoundingPrecision', argtypes=[WKT_WRITE_PTR, c_int])
+
 # WKBReader routines
 wkb_reader_create = GEOSFuncFactory('GEOSWKBReader_create', restype=WKB_READ_PTR)
 wkb_reader_destroy = GEOSFuncFactory('GEOSWKBReader_destroy', argtypes=[WKB_READ_PTR])
@@ -176,6 +179,15 @@ def outdim(self, new_dim):
             raise ValueError('WKT output dimension must be 2 or 3')
         wkt_writer_set_outdim(self.ptr, new_dim)
 
+    def set_trim(self, trim):
+        wkt_writer_set_trim(self.ptr, b'\x01' if trim else b'\x00')
+
+    def set_precision(self, precision):
+        if isinstance(precision, int) and precision >= 0 or precision is None:
+            wkt_writer_set_precision(self.ptr, -1 if precision is None else precision)
+        else:
+            raise ValueError('WKT output rounding precision must be non-negative integer or None.')
+
 
 class WKBWriter(IOBase):
     _constructor = wkb_writer_create

tests/gis_tests/geoadmin/models.py

@@ -1,4 +1,3 @@
-from django.contrib.gis.gdal import HAS_GDAL
 from django.utils.encoding import python_2_unicode_compatible
 
 from ..admin import admin
@@ -19,6 +18,21 @@ class Meta:
     def __str__(self):
         return self.name
 
+
+@python_2_unicode_compatible
+class CityMercator(models.Model):
+    name = models.CharField(max_length=30)
+    point = models.PointField(srid=3857)
+
+    objects = models.GeoManager()
+
+    class Meta:
+        app_label = 'geoadmin'
+        required_db_features = ['gis_enabled']
+
+    def __str__(self):
+        return self.name
+
 site = admin.AdminSite(name='admin_gis')
-if HAS_GDAL:
-    site.register(City, admin.OSMGeoAdmin)
+site.register(City, admin.OSMGeoAdmin)
+site.register(CityMercator, admin.OSMGeoAdmin)

tests/gis_tests/geoadmin/tests.py

@@ -1,11 +1,15 @@
 from __future__ import unicode_literals
 
+from unittest import skipUnless
+
 from django.contrib.gis import admin
+from django.contrib.gis.gdal import HAS_GDAL
 from django.contrib.gis.geos import Point
-from django.test import TestCase, override_settings, skipUnlessDBFeature
+from django.core.exceptions import ImproperlyConfigured
+from django.test import TestCase, mock, override_settings, skipUnlessDBFeature
 
 from .admin import UnmodifiableAdmin
-from .models import City, site
+from .models import City, CityMercator, site
 
 
 @skipUnlessDBFeature("gis_enabled")
@@ -52,6 +56,18 @@ def test_olmap_WMS_rendering(self):
             """"http://vmap0.tiles.osgeo.org/wms/vmap0", {layers: 'basic', format: 'image/jpeg'});""",
             result)
 
+    @mock.patch('django.contrib.gis.admin.options.HAS_GDAL', False)
+    def test_no_gdal_admin_model_diffent_srid(self):
+        with self.assertRaises(ImproperlyConfigured):
+            geoadmin = site._registry[City]
+            geoadmin.get_changelist_form(None)()
+
+    @mock.patch('django.contrib.gis.admin.options.HAS_GDAL', False)
+    def test_no_gdal_admin_model_same_srid(self):
+        geoadmin = site._registry[CityMercator]
+        geoadmin.get_changelist_form(None)()
+
+    @skipUnless(HAS_GDAL, "GDAL is required.")
     def test_olwidget_has_changed(self):
         """
         Check that changes are accurately noticed by OpenLayersWidget.