diff --git a/addons/membership/membership.py b/addons/membership/membership.py
index 4d015c0d455..ef8eaf0eadc 100644
--- a/addons/membership/membership.py
+++ b/addons/membership/membership.py
@@ -413,6 +413,16 @@ class Invoice(osv.osv):
             member_line_obj.write(cr, uid, mlines, {'date_cancel': today})
         return super(Invoice, self).action_cancel(cr, uid, ids, context=context)
 
+    # TODO master: replace by ondelete='cascade'
+    def unlink(self, cr, uid, ids, context=None):
+        member_line_obj = self.pool.get('membership.membership_line')
+        for invoice in self.browse(cr, uid, ids, context=context):
+            mlines = member_line_obj.search(cr, uid,
+                    [('account_invoice_line', 'in',
+                        [l.id for l in invoice.invoice_line])])
+            member_line_obj.unlink(cr, uid, mlines, context=context)
+        return super(Invoice, self).unlink(cr, uid, ids, context=context)
+
 
 class account_invoice_line(osv.osv):
     _inherit = 'account.invoice.line'
@@ -445,6 +455,7 @@ class account_invoice_line(osv.osv):
                     member_line_obj.unlink(cr, uid, ml_ids, context=context)
         return res
 
+    # TODO master: replace by ondelete='cascade'
     def unlink(self, cr, uid, ids, context=None):
         """Remove Membership Line Record for Account Invoice Line
         """
diff --git a/openerp/addons/base/tests/test_osv_expression.yml b/openerp/addons/base/tests/test_osv_expression.yml
index 1ed07c4a8ff..33707844750 100644
--- a/openerp/addons/base/tests/test_osv_expression.yml
+++ b/openerp/addons/base/tests/test_osv_expression.yml
@@ -420,11 +420,19 @@
         u1b = res_users.create(cr, uid, {'login': 'dbo2', 'partner_id': p1})
         u2 = res_users.create(cr, uid, {'login': 'rpo', 'partner_id': p2})
         assert [p1] == res_partner.search(cr, uid, [('user_ids', 'in', u1a)]), "o2m IN accept single int on right side"
+        assert [p1] == res_partner.search(cr, uid, [('user_ids', '=', 'Dédé Boitaclou')]), "o2m NOT IN matches none on the right side"
+        assert [] == res_partner.search(cr, uid, [('user_ids', 'in', [10000])]), "o2m NOT IN matches none on the right side"
         assert [p1,p2] == res_partner.search(cr, uid, [('user_ids', 'in', [u1a,u2])]), "o2m IN matches any on the right side"
         all_partners = res_partner.search(cr, uid, [])
         assert (set(all_partners) - set([p1])) == set(res_partner.search(cr, uid, [('user_ids', 'not in', u1a)])), "o2m NOT IN matches none on the right side"
+        # For 9.0: assert (set(all_partners) - set([p1])) == set(res_partner.search(cr, uid, [('user_ids', '!=', 'Dédé Boitaclou')])), "o2m NOT IN matches none on the right side"
         assert (set(all_partners) - set([p1,p2])) == set(res_partner.search(cr, uid, [('user_ids', 'not in', [u1b, u2])])), "o2m NOT IN matches none on the right side"
 
+
+
+
+
+
         # child_of x returns x and its children (direct or not).
         company = self.browse(cr, uid, ref('ymltest_company3'))
         expected = [ref('ymltest_company3'), ref('ymltest_company4')]
diff --git a/openerp/fields.py b/openerp/fields.py
index 081e75f6fba..dbf3ebbd15e 100644
--- a/openerp/fields.py
+++ b/openerp/fields.py
@@ -44,14 +44,17 @@ def _check_value(value):
 
 def copy_cache(records, env):
     """ Recursively copy the cache of ``records`` to the environment ``env``. """
-    for record, target in zip(records, records.with_env(env)):
-        if not target._cache:
+    todo, done = set(records), set()
+    while todo:
+        record = todo.pop()
+        if record not in done:
+            done.add(record)
+            target = record.with_env(env)
             for name, value in record._cache.iteritems():
                 if isinstance(value, BaseModel):
-                    target._cache[name] = value.with_env(env)
-                    copy_cache(value, env)
-                else:
-                    target._cache[name] = value
+                    todo.update(value)
+                    value = value.with_env(env)
+                target._cache[name] = value
 
 
 def resolve_mro(model, name, predicate):
diff --git a/openerp/osv/expression.py b/openerp/osv/expression.py
index 47b941485b2..196253232e3 100644
--- a/openerp/osv/expression.py
+++ b/openerp/osv/expression.py
@@ -985,6 +985,10 @@ class expression(object):
                             call_null = False
                             o2m_op = 'not in' if operator in NEGATIVE_TERM_OPERATORS else 'in'
                             push(create_substitution_leaf(leaf, ('id', o2m_op, ids1), model))
+                        elif operator in ('like', 'ilike', 'in', '='):
+                            # no match found with positive search operator => no result (FALSE_LEAF)
+                            call_null = False
+                            push(create_substitution_leaf(leaf, FALSE_LEAF, model))
 
                 if call_null:
                     o2m_op = 'in' if operator in NEGATIVE_TERM_OPERATORS else 'not in'