Ticket #13668: 13668.diff

django/db/models/fields/related.py

@@ -553 +553 @@
                         raise TypeError("'%s' instance expected" % self.model._meta.object_name)
                     else:
                         new_ids.add(obj)
-                db = router.db_for_write(self.through.__class__, instance=self.instance)
+                db = router.db_for_write(self.through, instance=self.instance)
                 vals = self.through._default_manager.using(db).values_list(target_field_name, flat=True)
                 vals = vals.filter(**{
                     source_field_name: self._pk_val,
@@ -595 +595 @@
                     else:
                         old_ids.add(obj)
                 # Work out what DB we're operating on
-                db = router.db_for_write(self.through.__class__, instance=self.instance)
+                db = router.db_for_write(self.through, instance=self.instance)
                 # Send a signal to the other end if need be.
                 if self.reverse or source_field_name == self.source_field_name:
                     # Don't send the signal when we are deleting the
@@ -616 +616 @@
                         model=self.model, pk_set=old_ids, using=db)
 
         def _clear_items(self, source_field_name):
-            db = router.db_for_write(self.through.__class__, instance=self.instance)
+            db = router.db_for_write(self.through, instance=self.instance)
             # source_col_name: the PK colname in join_table for the source object
             if self.reverse or source_field_name == self.source_field_name:
                 # Don't send the signal when we are clearing the

django/db/utils.py

@@ -123 +123 @@
             chosen_db = None
             for router in self.routers:
                 try:
-                    chosen_db = getattr(router, action)(model, **hints)
-                    if chosen_db:
-                        return chosen_db
+                    router_action = getattr(router, action)
                 except AttributeError:
                     # If the router doesn't have a method, skip to the next one.
-                    pass
+                    continue
+                chosen_db = router_action(model, **hints)
+                if chosen_db:
+                    return chosen_db
             try:
                 return hints['instance']._state.db or DEFAULT_DB_ALIAS
             except KeyError:

tests/regressiontests/multiple_database/tests.py

@@ -1759 +1759 @@
         b.authors.clear()
         self._write_to_default()
         self.assertEqual(receiver._database, "other")
+
+class AttributeErrorRouter(object):
+    "A router to test the exception handling of ConnectionRouter"
+    def db_for_read(self, model, **hints):
+        raise AttributeError
+
+    def db_for_write(self, model, **hints):
+        raise AttributeError
+
+class RouterAttributeErrorTestCase(TestCase):
+    multi_db = True
+
+    def setUp(self):
+        self.old_routers = router.routers
+        router.routers = [AttributeErrorRouter()]
+
+    def tearDown(self):
+        router.routers = self.old_routers
+
+    def test_attribute_error(self):
+        "Check that the AttributeError from AttributeErrorRouter bubbles up"
+        dive = Book()
+        dive.title="Dive into Python"
+        dive.published = datetime.date(2009, 5, 4)
+        self.assertRaises(AttributeError, dive.save)
+
+class ModelMetaRouter(object):
+    "A router to ensure model arguments are real model classes"
+    def db_for_write(self, model, **hints):
+        if not hasattr(model, '_meta'):
+            raise ValueError
+
+class RouterM2MThroughTestCase(TestCase):
+    multi_db = True
+
+    def setUp(self):
+        self.old_routers = router.routers
+        router.routers = [ModelMetaRouter()]
+
+    def tearDown(self):
+        router.routers = self.old_routers
+
+    def test_m2m_through(self):
+        b = Book.objects.create(title="Pro Django",
+                                published=datetime.date(2008, 12, 16))
+
+        p = Person.objects.create(name="Marty Alchin")
+        # test add
+        b.authors.add(p)
+        # test remove
+        b.authors.remove(p)
+        # test clear
+        b.authors.clear()