Make search on boolean non equals to True is the same as different of False

Closes #14815
(grafted from 7ac4b470f9e36f846b28d4c12e5e121e204d4aa1)

--HG--
branch : 8.0

trytond/trytond/model/fields/boolean.py

@@ -1,6 +1,8 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
 
+from sql import Null
+
 from .field import Field
 
 
@@ -33,4 +35,6 @@ class Boolean(Field):
                     expression |= (column == conv[value])
                 else:
                     expression &= (column != conv[value])
+            elif value and operator == '!=':
+                expression |= (column == Null)
         return expression

trytond/trytond/tests/test_field_boolean.py

@@ -229,6 +229,32 @@ class FieldBooleanTestCase(TestCase):
                 ])
         self.assertListEqual(booleans, [])
 
+    @with_transaction()
+    def test_search_equals_true_with_none(self):
+        "Test search boolean equals True with None"
+        Boolean = Pool().get('test.boolean')
+        boolean, = Boolean.create([{
+                    'boolean': None,
+                    }])
+
+        booleans = Boolean.search([
+                ('boolean', '=', True),
+                ])
+        self.assertListEqual(booleans, [])
+
+    @with_transaction()
+    def test_search_non_equals_true_with_none(self):
+        "Test search boolean non equals True with None"
+        Boolean = Pool().get('test.boolean')
+        boolean, = Boolean.create([{
+                    'boolean': None,
+                    }])
+
+        booleans = Boolean.search([
+                ('boolean', '!=', True),
+                ])
+        self.assertListEqual(booleans, [boolean])
+
     @with_transaction()
     def test_write_false(self):
         "Test write boolean False"