tests.py

    def test_webextension_generate_guid_no_error_on_deleted_addon(self):
        addon = Addon.from_upload(
            self.get_upload('webextension_no_id.xpi'),
            [self.platform])

        assert addon.guid is not None

        addon.guid = None
        addon.save()

        addon = Addon.from_upload(
            self.get_upload('webextension_no_id.xpi'),
            [self.platform])

        assert addon.guid is not None

        # Uploading the same addon without a id works.
        new_addon = Addon.from_upload(
            self.get_upload('webextension_no_id.xpi'),
            [self.platform])
        assert new_addon.guid is not None
        assert new_addon.guid != addon.guid