From 2de752afb4d28b156be7d13cc5618e3db9b4e198 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Sat, 22 Sep 2012 16:03:57 -0400
Subject: [PATCH] - [bug] Extra logic has been added to the "flush"     that
 occurs within Session.commit(), such that the     extra state added by an
 after_flush() or     after_flush_postexec() hook is also flushed in a    
 subsequent flush, before the "commit" completes.     Subsequent calls to
 flush() will continue until     the after_flush hooks stop adding new state. 
    An "overflow" counter of 100 is also in place,     in the event of a
 broken after_flush() hook     adding new content each time. [ticket:2566]

---
 CHANGES                       | 11 ++++++++
 lib/sqlalchemy/orm/session.py | 10 +++++++-
 test/orm/test_transaction.py  | 47 +++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index ed87284e30..d3ef996894 100644
--- a/CHANGES
+++ b/CHANGES
@@ -34,6 +34,17 @@ CHANGES
     "version" column, when using the "version" feature.
     Tests courtesy Daniel Miller.  [ticket:2539]
 
+  - [bug] Extra logic has been added to the "flush"
+    that occurs within Session.commit(), such that the
+    extra state added by an after_flush() or
+    after_flush_postexec() hook is also flushed in a
+    subsequent flush, before the "commit" completes.
+    Subsequent calls to flush() will continue until
+    the after_flush hooks stop adding new state.
+    An "overflow" counter of 100 is also in place,
+    in the event of a broken after_flush() hook
+    adding new content each time. [ticket:2566]
+
 - sql
   - [bug] Fixed CTE bug whereby positional
     bound parameters present in the CTEs themselves
diff --git a/lib/sqlalchemy/orm/session.py b/lib/sqlalchemy/orm/session.py
index 3710f32281..188c3b2e76 100644
--- a/lib/sqlalchemy/orm/session.py
+++ b/lib/sqlalchemy/orm/session.py
@@ -334,7 +334,15 @@ class SessionTransaction(object):
                 subtransaction.commit()
 
         if not self.session._flushing:
-            self.session.flush()
+            for _flush_guard in xrange(100):
+                if self.session._is_clean():
+                    break
+                self.session.flush()
+            else:
+                raise exc.FlushError(
+                        "Over 100 subsequent flushes have occurred within "
+                        "session.commit() - is an after_flush() hook "
+                        "creating new objects?")
 
         if self._parent is None and self.session.twophase:
             try:
diff --git a/test/orm/test_transaction.py b/test/orm/test_transaction.py
index 1fa5835b94..30bbd91946 100644
--- a/test/orm/test_transaction.py
+++ b/test/orm/test_transaction.py
@@ -318,6 +318,53 @@ class SessionTransactionTest(FixtureTest):
 
         eq_(len(sess.query(User).all()), 1)
 
+    def test_continue_flushing_on_commit(self):
+        """test that post-flush actions get flushed also if
+        we're in commit()"""
+        users, User = self.tables.users, self.classes.User
+
+        mapper(User, users)
+        sess = Session()
+
+        to_flush = [User(name='ed'), User(name='jack'), User(name='wendy')]
+        @event.listens_for(sess, "after_flush_postexec")
+        def add_another_user(session, ctx):
+            if to_flush:
+                session.add(to_flush.pop(0))
+
+        x = [1]
+        @event.listens_for(sess, "after_commit")
+        def add_another_user(session):
+            x[0] += 1
+
+        sess.add(to_flush.pop())
+        sess.commit()
+        eq_(x, [2])
+        eq_(
+            sess.scalar(select([func.count(users.c.id)])), 3
+        )
+
+    def test_continue_flushing_guard(self):
+        users, User = self.tables.users, self.classes.User
+
+        mapper(User, users)
+        sess = Session()
+
+        @event.listens_for(sess, "after_flush_postexec")
+        def add_another_user(session, ctx):
+            session.add(User(name='x'))
+        sess.add(User(name='x'))
+        assert_raises_message(
+            orm_exc.FlushError,
+            "Over 100 subsequent flushes have occurred",
+            sess.commit
+        )
+
+
+
+
+
+
     def test_error_on_using_inactive_session_commands(self):
         users, User = self.tables.users, self.classes.User
 
-- 
2.47.2