From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Mon, 12 Feb 2018 21:45:39 +0000 (-0500)
Subject: Add dependency for parent_pre post updates to parent deletes
X-Git-Tag: rel_1_2_3~10^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8607ae51fc5b74c181cdde6b89ade3ee30c12dad;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

Add dependency for parent_pre post updates to parent deletes

Fixed issue in post_update feature where an UPDATE is emitted
when the parent object has been deleted but the dependent object
is not.   This issue has existed for a long time however
since 1.2 now asserts rows matched for post_update, this
was raising an error.

Change-Id: I31b1d22408e358962577435f0c4cb9a456ba0872
Fixes: #4187
---

diff --git a/doc/build/changelog/unreleased_11/4187.rst b/doc/build/changelog/unreleased_11/4187.rst
new file mode 100644
index 0000000000..4be100e092
--- /dev/null
+++ b/doc/build/changelog/unreleased_11/4187.rst
@@ -0,0 +1,10 @@
+.. change::
+    :tags: bug, orm
+    :tickets: 4187
+    :versions: 1.2.3
+
+    Fixed issue in post_update feature where an UPDATE is emitted
+    when the parent object has been deleted but the dependent object
+    is not.   This issue has existed for a long time however
+    since 1.2 now asserts rows matched for post_update, this
+    was raising an error.
diff --git a/lib/sqlalchemy/orm/dependency.py b/lib/sqlalchemy/orm/dependency.py
index f05096a57b..799e633b3f 100644
--- a/lib/sqlalchemy/orm/dependency.py
+++ b/lib/sqlalchemy/orm/dependency.py
@@ -607,6 +607,7 @@ class ManyToOneDP(DependencyProcessor):
                 (before_delete, parent_pre_updates),
 
                 (parent_pre_updates, child_deletes),
+                (parent_pre_updates, parent_deletes),
             ])
         else:
             uow.dependencies.update([
diff --git a/test/orm/test_cycles.py b/test/orm/test_cycles.py
index abd05067aa..7528d9696f 100644
--- a/test/orm/test_cycles.py
+++ b/test/orm/test_cycles.py
@@ -639,6 +639,40 @@ class OneToManyManyToOneTest(fixtures.MappedTest):
         sess.add(p)
         sess.flush()
 
+    def test_post_update_m2o_no_cascade(self):
+        person, ball, Ball, Person = (self.tables.person,
+                                      self.tables.ball,
+                                      self.classes.Ball,
+                                      self.classes.Person)
+
+        mapper(Ball, ball)
+        mapper(Person, person, properties=dict(
+            favorite=relationship(
+                Ball, primaryjoin=person.c.favorite_ball_id == ball.c.id,
+                post_update=True)))
+        b = Ball(data='some data')
+        p = Person(data='some data')
+        p.favorite = b
+        sess = create_session()
+        sess.add(b)
+        sess.add(p)
+        sess.flush()
+
+        sess.delete(p)
+        self.assert_sql_execution(
+            testing.db,
+            sess.flush,
+            CompiledSQL("UPDATE person SET favorite_ball_id=:favorite_ball_id "
+                        "WHERE person.id = :person_id",
+                        lambda ctx: {
+                            'favorite_ball_id': None,
+                            'person_id': p.id}
+                        ),
+            CompiledSQL("DELETE FROM person WHERE person.id = :id",
+                        lambda ctx: {'id': p.id}
+                        ),
+        )
+
     def test_post_update_m2o(self):
         """A cycle between two rows, with a post_update on the many-to-one"""