From cf65d1e42e61e637653367b9fc484e98e8829c7f Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Sat, 10 Apr 2010 20:13:51 -0400
Subject: [PATCH] check_reverse was failing a not well covered m2m case.

---
 lib/sqlalchemy/orm/dependency.py    |  5 +--
 lib/sqlalchemy/orm/unitofwork.py    |  3 ++
 test/aaa_profiling/test_memusage.py |  2 +-
 test/orm/test_manytomany.py         | 56 ++++++++++++++++++++++++++++-
 4 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/lib/sqlalchemy/orm/dependency.py b/lib/sqlalchemy/orm/dependency.py
index 316c5382d0..b847946993 100644
--- a/lib/sqlalchemy/orm/dependency.py
+++ b/lib/sqlalchemy/orm/dependency.py
@@ -278,8 +278,9 @@ class DependencyProcessor(object):
         
         """
         for p in self.prop._reverse_property:
-            if not p.viewonly and p._dependency_processor:
-                return p.key < self.key
+            if not p.viewonly and p._dependency_processor and \
+                uow.has_dep(p._dependency_processor):
+                return True
         else:
             return False
 
diff --git a/lib/sqlalchemy/orm/unitofwork.py b/lib/sqlalchemy/orm/unitofwork.py
index 2c616943ff..756389fa7d 100644
--- a/lib/sqlalchemy/orm/unitofwork.py
+++ b/lib/sqlalchemy/orm/unitofwork.py
@@ -156,6 +156,9 @@ class UOWTransaction(object):
         else:
             return history.as_state()
     
+    def has_dep(self, processor):
+        return (processor, True) in self.presort_actions
+        
     def register_preprocessor(self, processor, fromparent):
         key = (processor, fromparent)
         if key not in self.presort_actions:
diff --git a/test/aaa_profiling/test_memusage.py b/test/aaa_profiling/test_memusage.py
index ba1f67ddf1..711b03a027 100644
--- a/test/aaa_profiling/test_memusage.py
+++ b/test/aaa_profiling/test_memusage.py
@@ -301,7 +301,7 @@ class MemUsageTest(EnsureZeroed):
             # dont need to clear_mappers()
             del B
             del A
-
+            
         metadata.create_all()
         try:
             go()
diff --git a/test/orm/test_manytomany.py b/test/orm/test_manytomany.py
index 84c60fc280..cac5fda781 100644
--- a/test/orm/test_manytomany.py
+++ b/test/orm/test_manytomany.py
@@ -1,4 +1,4 @@
-from sqlalchemy.test.testing import assert_raises, assert_raises_message
+from sqlalchemy.test.testing import assert_raises, assert_raises_message, eq_
 import sqlalchemy as sa
 from sqlalchemy.test import testing
 from sqlalchemy import Integer, String, ForeignKey
@@ -327,4 +327,58 @@ class M2MTest3(_base.MappedTest):
         # TODO: seems like just a test for an ancient exception throw.
         # how about some data/inserts/queries/assertions for this one
 
+class M2MTest4(_base.MappedTest):
+    @classmethod
+    def define_tables(cls, metadata):
+        table1 = Table("table1", metadata,
+            Column('col1', Integer, primary_key=True, test_needs_autoincrement=True),
+            Column('col2', String(30))
+            )
+
+        table2 = Table("table2", metadata,
+            Column('col1', Integer, primary_key=True, test_needs_autoincrement=True),
+            Column('col2', String(30)),
+            )
+
+        table3 = Table('table3', metadata,
+            Column('t1', Integer, ForeignKey('table1.col1')),
+            Column('t2', Integer, ForeignKey('table2.col1')),
+            )
+    
+    @testing.resolve_artifact_names
+    def test_delete_parent(self):
+        class A(_base.ComparableEntity):
+            pass
+        class B(_base.ComparableEntity):
+            pass
+
+        mapper(A, table1, properties={
+            'bs':relationship(B, secondary=table3, backref='as', order_by=table3.c.t1)
+        })
+        mapper(B, table2)
+
+        sess = create_session()
+        a1 = A(col2='a1')
+        a2 = A(col2='a2')
+        b1 = B(col2='b1')
+        b2 = B(col2='b2')
+        a1.bs.append(b1)
+        a2.bs.append(b2)
+        for x in [a1,a2]:
+            sess.add(x)
+        sess.flush()
+        sess.expunge_all()
+
+        alist = sess.query(A).order_by(A.col1).all()
+        eq_(
+            [
+                A(bs=[B(col2='b1')]), A(bs=[B(col2='b2')])
+            ],
+            alist)
+
+        for a in alist:
+            sess.delete(a)
+        sess.flush()
+        eq_(sess.query(table3).count(), 0)
+
 
-- 
2.47.3