[FIX] add if on vals

base_field_validator/models/ir_model.py

@@ -28,11 +28,12 @@ class IrModel(models.Model):
         for validator_line in model.validator_line_ids:
             if validator_line.field_id.name in vals:
                 pattern = re.compile(validator_line.regex_id.regex)
-                if not pattern.match(vals[validator_line.field_id.name]):
-                    raise Warning(
-                        _('Expression %s not valid for %s') % (
-                            validator_line.regex_id.regex,
-                            vals[validator_line.field_id.name]))
+                if vals[validator_line.field_id.name]:
+                    if not pattern.match(vals[validator_line.field_id.name]):
+                        raise Warning(
+                            _('Expression %s not valid for %s') % (
+                                validator_line.regex_id.regex,
+                                vals[validator_line.field_id.name]))
         return True