diff --git a/openerp/addons/base/test/test_osv_expression.yml b/openerp/addons/base/test/test_osv_expression.yml
index 2aab8293fb4..6ff02fb45f6 100644
--- a/openerp/addons/base/test/test_osv_expression.yml
+++ b/openerp/addons/base/test/test_osv_expression.yml
@@ -240,32 +240,40 @@
         assert res_2 == with_parent
         assert res_3 == partner_ids
         assert res_4 == with_parent
-        print ">>> ----------"
         # The results of these queries, when combined with queries 0..4 must
         # give the whole set of ids.
         res_5 = self.search(cr, uid, [('parent_id', 'like', 'probably_unexisting_name')])
+        res_5.sort()
         res_6 = self.search(cr, uid, [('parent_id', 'in', [max_partner_id + 1])])
+        res_6.sort()
         res_7 = self.search(cr, uid, [('parent_id', 'in', False)])
+        res_7.sort()
         res_8 = self.search(cr, uid, [('parent_id', 'in', [])])
+        res_8.sort()
         res_9 = self.search(cr, uid, [('parent_id', 'in', [False])])
-        print ">>>  5:", res_5
-        print ">>>  6:", res_6
-        print ">>>  7:", res_7
-        print ">>>  8:", res_8
-        print ">>>  9:", res_9
-        print ">>> ----------"
+        res_9.sort()
+        assert res_5 == []
+        assert res_6 == []
+        assert res_7 == without_parent
+        assert res_8 == []
+        assert res_9 == without_parent
         # These queries must return exactly the results than the queries 0..4,
         # i.e. not ... in ... must be the same as ... not in ... .
         res_10 = self.search(cr, uid, ['!', ('parent_id', 'like', 'probably_unexisting_name')])
+        res_10.sort()
         res_11 = self.search(cr, uid, ['!', ('parent_id', 'in', [max_partner_id + 1])])
+        res_11.sort()
         res_12 = self.search(cr, uid, ['!', ('parent_id', 'in', False)])
+        res_12.sort()
         res_13 = self.search(cr, uid, ['!', ('parent_id', 'in', [])])
+        res_13.sort()
         res_14 = self.search(cr, uid, ['!', ('parent_id', 'in', [False])])
-        print ">>> 10:", res_10
-        print ">>> 11:", res_11
-        print ">>> 12:", res_12
-        print ">>> 13:", res_13
-        print ">>> 14:", res_14
+        res_14.sort()
+        assert res_0 == res_10
+        assert res_1 == res_11
+        assert res_2 == res_12
+        assert res_3 == res_13
+        assert res_4 == res_14
 
         # Testing many2one field is not enough, a regular char field is tested
         # with in [] and must not return any result.
diff --git a/openerp/osv/expression.py b/openerp/osv/expression.py
index 8be06d5741c..0b613797f7b 100644
--- a/openerp/osv/expression.py
+++ b/openerp/osv/expression.py
@@ -128,6 +128,48 @@ def normalize_leaf(left, operator, right):
         operator = 'in' if operator == '=' else 'not in'
     return left, operator, right
 
+def distribute_not(domain):
+    """ Distribute the '!' operator on a normalized domain.
+    """
+    def negate(leaf):
+        left, operator, right = leaf
+        mapping = {
+            '<': '>=',
+            '>': '<=',
+            '<=': '>',
+            '>=': '<',
+            '=': '!=',
+            '!=': '=',
+        }
+        if operator in ('in', 'like', 'ilike'):
+            operator = 'not ' + operator
+            return [(left, operator, right)]
+        if operator in ('not in', 'not like', 'not ilike'):
+            operator = operator[4:]
+            return [(left, operator, right)]
+        if operator in mapping:
+            operator = mapping[operator]
+            return [(left, operator, right)]
+        return ['!', (left, operator, right)]
+    def distribute(domain):
+        if is_leaf(domain[0]):
+            return negate(domain[0]), domain[1:]
+        if domain[0] == '&':
+            done1, todo1 = distribute(domain[1:])
+            done2, todo2 = distribute(todo1)
+            return ['|'] + done1 + done2, todo2
+        if domain[0] == '|':
+            done1, todo1 = distribute(domain[1:])
+            done2, todo2 = distribute(todo1)
+            return ['&'] + done1 + done2, todo2
+    if not domain:
+        return []
+    if domain[0] != '!':
+        return [domain[0]] + distribute_not(domain[1:])
+    if domain[0] == '!':
+        done, todo = distribute(domain[1:])
+        return done + distribute_not(todo)
+
 def select_from_where(cr, s, f, w, ids, op):
     # todo: merge into parent query as sub-query
     res = []
@@ -162,7 +204,7 @@ class expression(object):
         self.__joins = []
         self.__main_table = None # 'root' table. set by parse()
         # assign self.__exp with the normalized, parsed domain.
-        self.parse(cr, uid, normalize(exp), table, context)
+        self.parse(cr, uid, distribute_not(normalize(exp)), table, context)
 
     # TODO used only for osv_memory
     @property