From 4bcd7e38e12ca2a74de1644b7d260497a64bc7dd Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 20 Aug 2013 13:27:27 -0400
Subject: [PATCH] Fixed bug where list instrumentation would fail to represent
 a setslice of ``[0:0]`` correctly, which in particular could occur when using
 ``insert(0, item)`` with the association proxy.  Due to some quirk in Python
 collections, the issue was much more likely with Python 3 rather than 2. 
 Also in 0.8.3, 0.7.11. [ticket:2807]

Conflicts:
	doc/build/changelog/changelog_09.rst

Conflicts:
	doc/build/changelog/changelog_08.rst
---
 doc/build/changelog/changelog_07.rst | 10 ++++++++++
 lib/sqlalchemy/orm/collections.py    |  5 ++++-
 test/orm/test_collection.py          | 11 ++++++++---
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/doc/build/changelog/changelog_07.rst b/doc/build/changelog/changelog_07.rst
index 738e897463..d7d3019d2e 100644
--- a/doc/build/changelog/changelog_07.rst
+++ b/doc/build/changelog/changelog_07.rst
@@ -6,6 +6,16 @@
 .. changelog::
     :version: 0.7.11
 
+    .. change::
+        :tags: bug, orm
+        :tickets: 2807
+
+        Fixed bug where list instrumentation would fail to represent a
+        setslice of ``[0:0]`` correctly, which in particular could occur
+        when using ``insert(0, item)`` with the association proxy.  Due
+        to some quirk in Python collections, the issue was much more likely
+        with Python 3 rather than 2.
+
     .. change::
         :tags: bug, sql
         :tickets: 2801
diff --git a/lib/sqlalchemy/orm/collections.py b/lib/sqlalchemy/orm/collections.py
index e26a59731f..bb2d272c4c 100644
--- a/lib/sqlalchemy/orm/collections.py
+++ b/lib/sqlalchemy/orm/collections.py
@@ -1078,7 +1078,10 @@ def _list_decorators():
                 start = index.start or 0
                 if start < 0:
                     start += len(self)
-                stop = index.stop or len(self)
+                if index.stop is not None:
+                    stop = index.stop
+                else:
+                    stop = len(self)
                 if stop < 0:
                     stop += len(self)
 
diff --git a/test/orm/test_collection.py b/test/orm/test_collection.py
index b3de03aaef..0f54da5517 100644
--- a/test/orm/test_collection.py
+++ b/test/orm/test_collection.py
@@ -127,9 +127,9 @@ class CollectionsTest(fixtures.ORMTest):
         control = list()
 
         def assert_eq():
-            self.assert_(set(direct) == canary.data)
-            self.assert_(set(adapter) == canary.data)
-            self.assert_(direct == control)
+            eq_(set(direct), canary.data)
+            eq_(set(adapter), canary.data)
+            eq_(direct, control)
 
         # assume append() is available for list tests
         e = creator()
@@ -259,6 +259,11 @@ class CollectionsTest(fixtures.ORMTest):
             control[-2:-1] = values
             assert_eq()
 
+            values = [creator()]
+            direct[0:0] = values
+            control[0:0] = values
+            assert_eq()
+
 
         if hasattr(direct, '__delitem__') or hasattr(direct, '__delslice__'):
             for i in range(1, 4):
-- 
2.47.2