Ticket #10808: base.py.diff

base.py

@@ -273 +273 @@
         # Now we're left with the unprocessed fields that *must* come from
         # keywords, or default.
 
+        # We're creating a set to keep track of which fields have already 
+        # been assigned values. In the case of diamond inheritance, where 
+        # B and C inherit from A, and D inherits from B and C, D will have
+        # "redundant" copies of each of A's fields. As we iterate through 
+        # all the fields, the second time we see a field we run the risk of
+        # reassigning it the default value, so if a field has already been
+        # seen in set_fields, we ignore it.
+        set_fields = set()
         for field in fields_iter:
+            if field.attname in set_fields:
+                continue
             is_related_object = False
             # This slightly odd construct is so that we can access any
             # data-descriptor object (DeferredAttribute) without triggering its
@@ -311 +321 @@
                 setattr(self, field.name, rel_obj)
             else:
                 setattr(self, field.attname, val)
+            set_fields.add(field.attname) 
 
         if kwargs:
             for prop in kwargs.keys():