Ticket #2363: tighter_subclasscheck.patch

tests/modeltests/invalid_models/models.py

@@ -97 +97 @@
     m2m_3 = models.ManyToManyField('self', symmetrical=False)
     m2m_4 = models.ManyToManyField('self', symmetrical=False)
 
+class Model(models.Model):
+    "But it's valid to call a model Model."
+    year = models.PositiveIntegerField() #1960
+    make = models.CharField(maxlength=10) #Aston Martin
+    name = models.CharField(maxlength=10) #DB 4 GT
+
+class Car(models.Model):
+    colour = models.CharField(maxlength=5)
+    model = models.ForeignKey(Model)
+
 model_errors = """invalid_models.fielderrors: "charfield": CharFields require a "maxlength" attribute.
 invalid_models.fielderrors: "floatfield": FloatFields require a "decimal_places" attribute.
 invalid_models.fielderrors: "floatfield": FloatFields require a "max_digits" attribute.

django/db/models/base.py

@@ -22 +22 @@
     "Metaclass for all models"
     def __new__(cls, name, bases, attrs):
         # If this isn't a subclass of Model, don't do anything special.
-        if name == 'Model' or not filter(lambda b: issubclass(b, Model), bases):
+        if (name == 'Model' and attrs['__module__'] == __name__)\
+         or not filter(lambda b: issubclass(b, Model), bases):
             return super(ModelBase, cls).__new__(cls, name, bases, attrs)
 
         # Create the class.