diff --git a/odoo/addons/base/tests/test_expression.py b/odoo/addons/base/tests/test_expression.py
index e8cf33ef24c..2a7df364cc6 100644
--- a/odoo/addons/base/tests/test_expression.py
+++ b/odoo/addons/base/tests/test_expression.py
@@ -604,6 +604,37 @@ class TestExpression(SavepointCaseWithUserDemo):
         self.assertNotIn(helene, Company.search([('name','not ilike','Helene')]))
         self.assertNotIn(helene, Company.search([('name','not ilike','hélène')]))
 
+    def test_pure_function(self):
+        orig_false = expression.FALSE_DOMAIN.copy()
+        orig_true = expression.TRUE_DOMAIN.copy()
+        false = orig_false.copy()
+        true = orig_true.copy()
+
+        domain = expression.AND([])
+        domain += [('id', '=', 1)]
+        domain = expression.AND([])
+        self.assertEqual(domain, orig_true)
+
+        domain = expression.AND([false])
+        domain += [('id', '=', 1)]
+        domain = expression.AND([false])
+        self.assertEqual(domain, orig_false)
+
+        domain = expression.OR([])
+        domain += [('id', '=', 1)]
+        domain = expression.OR([])
+        self.assertEqual(domain, orig_false)
+
+        domain = expression.OR([true])
+        domain += [('id', '=', 1)]
+        domain = expression.OR([true])
+        self.assertEqual(domain, orig_true)
+
+        domain = expression.normalize_domain([])
+        domain += [('id', '=', 1)]
+        domain = expression.normalize_domain([])
+        self.assertEqual(domain, orig_true)
+
     def test_like_wildcards(self):
         # check that =like/=ilike expressions are working on an untranslated field
         Partner = self.env['res.partner']
diff --git a/odoo/osv/expression.py b/odoo/osv/expression.py
index e9efe04fc96..35c66c7f923 100644
--- a/odoo/osv/expression.py
+++ b/odoo/osv/expression.py
@@ -191,7 +191,7 @@ def normalize_domain(domain):
     """
     assert isinstance(domain, (list, tuple)), "Domains to normalize must have a 'domain' form: a list or tuple of domain components"
     if not domain:
-        return TRUE_DOMAIN
+        return [TRUE_LEAF]
     result = []
     expected = 1                            # expected number of expressions
     op_arity = {NOT_OPERATOR: 1, AND_OPERATOR: 2, OR_OPERATOR: 2}
@@ -269,12 +269,12 @@ def combine(operator, unit, zero, domains):
 
 def AND(domains):
     """AND([D1,D2,...]) returns a domain representing D1 and D2 and ... """
-    return combine(AND_OPERATOR, TRUE_DOMAIN, FALSE_DOMAIN, domains)
+    return combine(AND_OPERATOR, [TRUE_LEAF], [FALSE_LEAF], domains)
 
 
 def OR(domains):
     """OR([D1,D2,...]) returns a domain representing D1 or D2 or ... """
-    return combine(OR_OPERATOR, FALSE_DOMAIN, TRUE_DOMAIN, domains)
+    return combine(OR_OPERATOR, [FALSE_LEAF], [TRUE_LEAF], domains)
 
 
 def distribute_not(domain):
@@ -752,7 +752,7 @@ class expression(object):
                 either as a range using the parent_path tree lookup field
                 (when available), or as an expanded [(left,in,child_ids)] """
             if not ids:
-                return FALSE_DOMAIN
+                return [FALSE_LEAF]
             if left_model._parent_store:
                 doms = OR([
                     [('parent_path', '=like', rec.parent_path + '%')]