From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 4 Dec 2007 17:55:25 +0000 (+0000)
Subject: - fixed backref bug where you could not del instance.attr if attr
X-Git-Tag: rel_0_4_2~112
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=c6bda7dcc89ae5f7842f0e900d3917024a74eb29;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- fixed backref bug where you could not del instance.attr if attr
was None
---

diff --git a/CHANGES b/CHANGES
index e3ce282cfb..dea30fd218 100644
--- a/CHANGES
+++ b/CHANGES
@@ -38,6 +38,9 @@ CHANGES
      ColumnElement is accepted now, as the compiler auto-labels non-labeled
      ColumnElements now.  a selectable, like a select() statement, still
      requires conversion to ColumnElement via as_scalar() or label().
+
+   - fixed backref bug where you could not del instance.attr if attr
+     was None
      
    - several ORM attributes have been removed or made private:
      mapper.get_attr_by_column(), mapper.set_attr_by_column(), 
diff --git a/lib/sqlalchemy/orm/attributes.py b/lib/sqlalchemy/orm/attributes.py
index 5e3747e002..8268d0816c 100644
--- a/lib/sqlalchemy/orm/attributes.py
+++ b/lib/sqlalchemy/orm/attributes.py
@@ -564,7 +564,8 @@ class GenericBackrefExtension(interfaces.AttributeExtension):
         getattr(child.__class__, self.key).impl.append(child._state, instance, initiator)
 
     def remove(self, instance, child, initiator):
-        getattr(child.__class__, self.key).impl.remove(child._state, instance, initiator)
+        if child is not None:
+            getattr(child.__class__, self.key).impl.remove(child._state, instance, initiator)
 
 class ClassState(object):
     """tracks state information at the class level."""
diff --git a/test/orm/attributes.py b/test/orm/attributes.py
index 88c353cd13..4e41f0a295 100644
--- a/test/orm/attributes.py
+++ b/test/orm/attributes.py
@@ -203,6 +203,10 @@ class AttributesTest(PersistTest):
         p4.blog = b
         self.assert_(b.posts == [p1, p2, p4])
 
+        # assert no failure removing None
+        p5 = Post()
+        p5.blog = None
+        del p5.blog
 
         class Port(object):pass
         class Jack(object):pass