Check the existence of a getter before adding it to a field depends

Closes #15055

trytond/trytond/model/modelview.py

@@ -170,6 +170,7 @@ class ModelView(Model):
                     depend = depend[len('_parent_'):]
                 if dep_field := getattr(cls, depend, None):
                     if (isinstance(dep_field, fields.Function)
+                            and dep_field.getter
                             and dep_field.getter.startswith('on_change_with')):
                         meth_names.append(dep_field.getter)
 

trytond/trytond/tests/test_field_depends.py

@@ -273,8 +273,9 @@ class FieldDependsTestCase(TestCase):
             test = fields.Char("Test")
             foo = fields.Function(fields.Char("Foo"), 'on_change_with_foo')
             bar = fields.Char("Bar")
+            baz = fields.Function(fields.Char("Baz"))
 
-            @fields.depends('foo')
+            @fields.depends('foo', 'baz')
             def on_change_test(self):
                 pass
 
@@ -282,7 +283,12 @@ class FieldDependsTestCase(TestCase):
             def on_change_with_foo(self, name=None):
                 pass
 
+            @classmethod
+            def column_baz(cls, tables):
+                t, _ = tables[None]
+                return t.bar
+
         Model.__setup__()
         Model.__post_setup__()
 
-        self.assertEqual(Model.test.on_change, {'foo', 'bar'})
+        self.assertEqual(Model.test.on_change, {'foo', 'bar', 'baz'})