[1.9.x] Fixed #26413 -- Fixed a regression with abstract model inheritance and explicit parent links.

Thanks Trac alias trkjgrdg for the report and Tim for investigation and review.

Backport of 67cf5efa31acb2916034afb15610b700695dfcb0 from master

1 files changed, 9 insertions, 1 deletions

diff --git a/django/db/models/base.py b/django/db/models/base.py
index e1a94d34d1..5635fabd6a 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -245,13 +245,21 @@ class ModelBase(type):
                     field = None
                 new_class._meta.parents[base] = field
             else:
+                base_parents = base._meta.parents.copy()
+
                 # .. and abstract ones.
                 for field in parent_fields:
                     new_field = copy.deepcopy(field)
                     new_class.add_to_class(field.name, new_field)
+                    # Replace parent links defined on this base by the new
+                    # field as it will be appropriately resolved if required.
+                    if field.one_to_one:
+                        for parent, parent_link in base_parents.items():
+                            if field == parent_link:
+                                base_parents[parent] = new_field
 
                 # Pass any non-abstract parent classes onto child.
-                new_class._meta.parents.update(base._meta.parents)
+                new_class._meta.parents.update(base_parents)
 
             # Inherit managers from the abstract base classes.
             new_class.copy_managers(base._meta.abstract_managers)