From 6b078044745ee3c665051a886021c6fd1f6873b6 Mon Sep 17 00:00:00 2001
From: Andrew Godwin <andrew@aeracode.org>
Date: Sat, 8 Mar 2014 15:57:25 -0800
Subject: [PATCH] Fixed #22183: Through M2Ms now correctly handled

---
 django/db/backends/schema.py        |  3 ++-
 django/db/models/fields/related.py  |  5 +++++
 tests/field_deconstruction/tests.py |  6 ++++++
 tests/schema/models.py              | 15 +++++++++++++++
 tests/schema/tests.py               | 18 ++++++++++++++++--
 5 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/django/db/backends/schema.py b/django/db/backends/schema.py
index 862b22f901..ef53ac1608 100644
--- a/django/db/backends/schema.py
+++ b/django/db/backends/schema.py
@@ -262,7 +262,8 @@ class BaseDatabaseSchemaEditor(object):
             })
         # Make M2M tables
         for field in model._meta.local_many_to_many:
-            self.create_model(field.rel.through)
+            if field.rel.through._meta.auto_created:
+                self.create_model(field.rel.through)
 
     def delete_model(self, model):
         """
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index e4c055ff63..41c020f509 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -2032,6 +2032,11 @@ class ManyToManyField(RelatedField):
             kwargs['to'] = self.rel.to
         else:
             kwargs['to'] = "%s.%s" % (self.rel.to._meta.app_label, self.rel.to._meta.object_name)
+        if getattr(self.rel, 'through', None) is not None:
+            if isinstance(self.rel.through, six.string_types):
+                kwargs['through'] = self.rel.through
+            else:
+                kwargs['through'] = "%s.%s" % (self.rel.through._meta.app_label, self.rel.through._meta.object_name)
         # If swappable is True, then see if we're actually pointing to the target
         # of a swap.
         swappable_setting = self.swappable_setting
diff --git a/tests/field_deconstruction/tests.py b/tests/field_deconstruction/tests.py
index 0d24c2a268..26ceb4e0cf 100644
--- a/tests/field_deconstruction/tests.py
+++ b/tests/field_deconstruction/tests.py
@@ -242,6 +242,12 @@ class FieldDeconstructionTests(TestCase):
         self.assertEqual(args, [])
         self.assertEqual(kwargs, {"to": "auth.User"})
         self.assertEqual(kwargs['to'].setting_name, "AUTH_USER_MODEL")
+        # Test through
+        field = models.ManyToManyField("auth.Permission", through="auth.Group")
+        name, path, args, kwargs = field.deconstruct()
+        self.assertEqual(path, "django.db.models.ManyToManyField")
+        self.assertEqual(args, [])
+        self.assertEqual(kwargs, {"to": "auth.Permission", "through": "auth.Group"})
 
     @override_settings(AUTH_USER_MODEL="auth.Permission")
     def test_many_to_many_field_swapped(self):
diff --git a/tests/schema/models.py b/tests/schema/models.py
index 67cfcf6a89..f85a3c6362 100644
--- a/tests/schema/models.py
+++ b/tests/schema/models.py
@@ -44,6 +44,21 @@ class BookWithM2M(models.Model):
         apps = new_apps
 
 
+class TagThrough(models.Model):
+    book = models.ForeignKey("schema.BookWithM2MThrough")
+    tag = models.ForeignKey("schema.TagM2MTest")
+
+    class Meta:
+        apps = new_apps
+
+
+class BookWithM2MThrough(models.Model):
+    tags = models.ManyToManyField("TagM2MTest", related_name="books", through=TagThrough)
+
+    class Meta:
+        apps = new_apps
+
+
 class BookWithSlug(models.Model):
     author = models.ForeignKey(Author)
     title = models.CharField(max_length=100, db_index=True)
diff --git a/tests/schema/tests.py b/tests/schema/tests.py
index a502ef6002..3eb826cee4 100644
--- a/tests/schema/tests.py
+++ b/tests/schema/tests.py
@@ -9,7 +9,7 @@ from django.db.models.fields.related import ManyToManyField, ForeignKey
 from django.db.transaction import atomic
 from .models import (Author, AuthorWithM2M, Book, BookWithLongName,
     BookWithSlug, BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename,
-    UniqueTest, Thing)
+    UniqueTest, Thing, TagThrough, BookWithM2MThrough)
 
 
 class SchemaTests(TransactionTestCase):
@@ -26,7 +26,7 @@ class SchemaTests(TransactionTestCase):
     models = [
         Author, AuthorWithM2M, Book, BookWithLongName, BookWithSlug,
         BookWithM2M, Tag, TagIndexed, TagM2MTest, TagUniqueRename, UniqueTest,
-        Thing
+        Thing, TagThrough, BookWithM2MThrough
     ]
 
     # Utility functions
@@ -310,6 +310,20 @@ class SchemaTests(TransactionTestCase):
         columns = self.column_classes(BookWithM2M._meta.get_field_by_name("tags")[0].rel.through)
         self.assertEqual(columns['tagm2mtest_id'][0], "IntegerField")
 
+    def test_m2m_create_through(self):
+        """
+        Tests M2M fields on models during creation with through models
+        """
+        # Create the tables
+        with connection.schema_editor() as editor:
+            editor.create_model(TagThrough)
+            editor.create_model(TagM2MTest)
+            editor.create_model(BookWithM2MThrough)
+        # Ensure there is now an m2m table there
+        columns = self.column_classes(TagThrough)
+        self.assertEqual(columns['book_id'][0], "IntegerField")
+        self.assertEqual(columns['tag_id'][0], "IntegerField")
+
     def test_m2m(self):
         """
         Tests adding/removing M2M fields on models