id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
13670	postgis adapter fails to compare against empty string	milosu	nobody	"following test case fails:

{{{
from django.db.models import Q
from django.contrib.gis.db import models

class Area(models.Model):
    poly = models.PolygonField(srid=4326, verbose_name=u""area repr"")
    objects = models.GeoManager()

class District(models.Model):
    poly = models.PolygonField(srid=4326, verbose_name=u""district repr"")
    objects = models.GeoManager()

class Factory(models.Model):
    area = models.ForeignKey(Area)
    district = models.ForeignKey(District)

__test__ = {'API_TESTS':""""""

>>> from django.contrib.gis.geos import fromstr
>>> location = fromstr('POINT (5 7)')
>>> a, created = Area.objects.get_or_create(poly=fromstr('POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))'))
>>> d, created = District.objects.get_or_create(poly=fromstr('POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))'))
>>> f, created = Factory.objects.get_or_create(area=a, district=d)
>>> areas = Area.objects.filter(poly__intersects = location)
>>> districts = District.objects.filter(poly__intersects = location)
>>> qobj = Q(area__isnull=True)&Q(district__isnull=True)
>>> qobj |= (Q(area__in = areas)|Q(district__in = districts))
>>> match = Factory.objects.filter(qobj)
>>> match2 = Factory.objects.filter(id__in = match)
>>> match2.count()
        1
""""""}
}}}

the last line will raise an exception in django.contrib.gis.db.backends.postgis.adapter __eq__ due to the comparision against empty string

the following patch solves the problem:

{{{
Index: adapter.py
===================================================================
--- adapter.py  (revision 3756)
+++ adapter.py  (working copy)
@@ -21,6 +21,8 @@
             raise Exception('Error implementing psycopg2 protocol. Is psycopg2 installed?')
 
     def __eq__(self, other):
+        if not isinstance(other, PostGISAdapter):
+           return False
         return (self.ewkb == other.ewkb) and (self.srid == other.srid)
 
     def __str__(self):
}}}
"	Bug	closed	GIS	1.2	Normal	fixed		milosu john@…	Accepted	1	0	0	0	0	0