PasswordType now falls back to default length (1024) if no schemes were found in crypt context

sqlalchemy_utils/types/password.py

@@ -88,7 +88,7 @@ class PasswordType(types.TypeDecorator, ScalarCoercible):
         if max_length is None:
             # Calculate the largest possible encoded password.
             # name + rounds + salt + hash + ($ * 4) of largest hash
-            max_lengths = []
+            max_lengths = [1024]
             for name in self.context.schemes():
                 scheme = getattr(__import__('passlib.hash').hash, name)
                 length = 4 + len(scheme.name)

tests/types/test_password.py

@@ -8,7 +8,6 @@ from sqlalchemy_utils import Password, PasswordType
 
 @mark.skipif('password.passlib is None')
 class TestPasswordType(TestCase):
-
     def create_models(self):
         class User(self.Base):
             __tablename__ = 'user'
@@ -86,3 +85,6 @@ class TestPasswordType(TestCase):
         expected_length += 4
 
         assert impl.length == expected_length
+
+    def test_without_schemes(self):
+        assert PasswordType(schemes=[]).length == 1024