Fixed #17615 -- Corrected unique field validation when using multitable inheritance. The validation used wrong pk value if the parent and child model had different pk fields. Thanks ungenio for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17920 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 7 insertions, 3 deletions

diff --git a/django/db/models/base.py b/django/db/models/base.py
index fc38224345..e28add30a9 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -718,9 +718,13 @@ class Model(object):
 
             # Exclude the current object from the query if we are editing an
             # instance (as opposed to creating a new one)
-            if not self._state.adding and self.pk is not None:
-                qs = qs.exclude(pk=self.pk)
-
+            # Note that we need to use the pk as defined by model_class, not
+            # self.pk. These can be different fields because model inheritance
+            # allows single model to have effectively multiple primary keys.
+            # Refs #17615.
+            model_class_pk = self._get_pk_val(model_class._meta)
+            if not self._state.adding and model_class_pk is not None:
+                qs = qs.exclude(pk=model_class_pk)
             if qs.exists():
                 if len(unique_check) == 1:
                     key = unique_check[0]