Fixed #17002 -- Allowed using a ManyToManyField through model that inherits another.

1 files changed, 6 insertions, 16 deletions

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index a1e476c592..5eea5ad939 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -19,7 +19,7 @@ from django.db.models.constants import LOOKUP_SEP
 from django.db.models.expressions import Col, Ref
 from django.db.models.fields.related_lookups import MultiColSource
 from django.db.models.query_utils import (
-    PathInfo, Q, check_rel_lookup_compatibility, refs_expression,
+    Q, check_rel_lookup_compatibility, refs_expression,
 )
 from django.db.models.sql.constants import (
     INNER, LOUTER, ORDER_DIR, ORDER_PATTERN, QUERY_TERMS, SINGLE,
@@ -1342,21 +1342,11 @@ class Query(object):
             # field lives in parent, but we are currently in one of its
             # children)
             if model is not opts.model:
-                # The field lives on a base class of the current model.
-                # Skip the chain of proxy to the concrete proxied model
-                proxied_model = opts.concrete_model
-
-                for int_model in opts.get_base_chain(model):
-                    if int_model is proxied_model:
-                        opts = int_model._meta
-                    else:
-                        final_field = opts.parents[int_model]
-                        targets = (final_field.remote_field.get_related_field(),)
-                        opts = int_model._meta
-                        path.append(PathInfo(final_field.model._meta, opts, targets, final_field, False, True))
-                        cur_names_with_path[1].append(
-                            PathInfo(final_field.model._meta, opts, targets, final_field, False, True)
-                        )
+                path_to_parent = opts.get_path_to_parent(model)
+                if path_to_parent:
+                    path.extend(path_to_parent)
+                    cur_names_with_path[1].extend(path_to_parent)
+                    opts = path_to_parent[-1].to_opts
             if hasattr(field, 'get_path_info'):
                 pathinfos = field.get_path_info()
                 if not allow_many: