--- a/server/migractions.py	Wed Mar 17 09:23:05 2010 +0100
+++ b/server/migractions.py	Wed Mar 17 09:23:17 2010 +0100
@@ -15,6 +15,8 @@
 :contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
 :license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
 """
+from __future__ import with_statement
+
 __docformat__ = "restructuredtext en"
 
 import sys
@@ -40,7 +42,7 @@
                              CubicWebRelationSchema, order_eschemas)
 from cubicweb.dbapi import get_repository, repo_connect
 from cubicweb.migration import MigrationHelper, yes
-
+from cubicweb.server.session import hooks_control
 try:
     from cubicweb.server import SOURCE_TYPES, schemaserial as ss
     from cubicweb.server.utils import manager_userpasswd, ask_source_config
@@ -96,7 +98,9 @@
                 self.backup_database()
             elif options.backup_db:
                 self.backup_database(askconfirm=False)
-        super(ServerMigrationHelper, self).migrate(vcconf, toupgrade, options)
+        # disable notification during migration
+        with hooks_control(self.session, self.session.HOOKS_ALLOW_ALL, 'notification'):
+            super(ServerMigrationHelper, self).migrate(vcconf, toupgrade, options)
 
     def cmd_process_script(self, migrscript, funcname=None, *args, **kwargs):
         """execute a migration script

--- a/server/session.py	Wed Mar 17 09:23:05 2010 +0100
+++ b/server/session.py	Wed Mar 17 09:23:17 2010 +0100
@@ -153,7 +153,12 @@
     def hijack_user(self, user):
         """return a fake request/session using specified user"""
         session = Session(user, self.repo)
-        session._threaddata.pool = self.pool
+        threaddata = session._threaddata
+        threaddata.pool = self.pool
+        # everything in transaction_data should be copied back but the entity
+        # type cache we don't want to avoid security pb
+        threaddata.transaction_data = self.transaction_data.copy()
+        threaddata.transaction_data.pop('ecache', None)
         return session
 
     def add_relation(self, fromeid, rtype, toeid):