gis: Fixed #8207; now shield 2.4 test runners from attempting to import ctypes.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8289 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/gdal/__init__.py

@@ -47,9 +47,13 @@ except:
     HAS_GDAL, GEOJSON = False, False
 
 # The envelope, error, and geomtype modules do not actually require the
-#  GDAL library.
+# GDAL library, but still nead at least Python 2.4 and ctypes.
 PYTHON23 = sys.version_info[0] == 2 and sys.version_info[1] == 3
 if not PYTHON23:
+    try:
         from django.contrib.gis.gdal.envelope import Envelope
         from django.contrib.gis.gdal.error import check_err, OGRException, OGRIndexError, SRSException
         from django.contrib.gis.gdal.geomtype import OGRGeomType
+    except ImportError:
+        # No ctypes, but don't raise an exception.
+        pass

django/contrib/gis/models.py

@@ -214,11 +214,10 @@ if not PYTHON23 and settings.DATABASE_ENGINE == 'postgresql_psycopg2':
     # Because the PostGIS version is checked when initializing the spatial 
     # backend a `ProgrammingError` will be raised if the PostGIS tables 
     # and functions are not installed.  We catch here so it won't be raised when 
-    # running the Django test suite.
-    from psycopg2 import ProgrammingError
+    # running the Django test suite.  `ImportError` is also possible if no ctypes.
     try:
         from django.contrib.gis.db.backend.postgis.models import GeometryColumns, SpatialRefSys
-    except ProgrammingError:
+    except:
         _srid_info = False
 elif not PYTHON23 and settings.DATABASE_ENGINE == 'oracle':
     # Same thing as above, except the GEOS library is attempted to be loaded for