This patch is  a cruded attemt to make @commit_on_success support
nested transactions. See http://code.djangoproject.com/ticket/2227
for an explanation why this is usefull.

  --md@hudora.de

Index: django/db/transaction.py
===================================================================
--- django/db/transaction.py	(revision 3262)
+++ django/db/transaction.py	(working copy)
@@ -187,21 +187,26 @@
     control in web apps.
     """
     def _commit_on_success(*args, **kw):
-        try:
-            enter_transaction_management()
-            managed(True)
+        # only use transactions if we don't have already an ongoing transaction
+        thread_ident = thread.get_ident()
+        if thread_ident not in state or state[thread_ident] == []:
             try:
-                res = func(*args, **kw)
-            except Exception, e:
-                if is_dirty():
-                    rollback()
-                raise
-            else:
-                if is_dirty():
-                    commit()
-            return res
-        finally:
-            leave_transaction_management()
+                enter_transaction_management()
+                managed(True)
+                try:
+                    res = func(*args, **kw)
+                except Exception, e:
+                    if is_dirty():
+                        rollback()
+                    raise
+                else:
+                    if is_dirty():
+                        commit()
+                return res
+            finally:
+                leave_transaction_management()
+        else:
+            return func(*args, **kw)
     return _commit_on_success
 
 def commit_manually(func):