Make sure code will fall back if implementation scripts are not

provided.
Fallback means that no authentication policy will be applied if former
is true.

product/ERP5/mixin/login_account_provider.py

@@ -45,6 +45,7 @@ class LoginAccountProviderMixin:
     Notify an authentication failure.
     """
     method = self._getTypeBasedMethod('notifyLoginFailure')
+    if method is not None:
       return method(**kw)
 
   security.declareProtected(Permissions.SetOwnPassword, 'notifyPasswordExpire')
@@ -53,6 +54,7 @@ class LoginAccountProviderMixin:
     Notify a password expire event.
     """
     method = self._getTypeBasedMethod('notifyPasswordExpire')
+    if method is not None:
       return method(**kw)
 
   security.declareProtected(Permissions.SetOwnPassword, 'isLoginBlocked')
@@ -61,7 +63,9 @@ class LoginAccountProviderMixin:
     Is this login blocked?
     """
     method = self._getTypeBasedMethod('isLoginBlocked')
+    if method is not None:
       return method(**kw)
+    return False      
 
   security.declareProtected(Permissions.SetOwnPassword, 'isPasswordExpired')
   def isPasswordExpired(self, **kw):
@@ -69,7 +73,9 @@ class LoginAccountProviderMixin:
     Is password expired?
     """
     method = self._getTypeBasedMethod('isPasswordExpired')
+    if method is not None:
       return method(**kw)
+    return False      
 
   security.declareProtected(Permissions.SetOwnPassword, 'isPasswordValid')
   def isPasswordValid(self, password, **kw):
@@ -77,7 +83,9 @@ class LoginAccountProviderMixin:
     Is password valid?
     """
     method = self._getTypeBasedMethod('isPasswordValid')
+    if method is not None:
       return method(password, **kw)
+    return True      
     
   security.declareProtected(Permissions.SetOwnPassword, 'isPasswordAlreadyUsed')
   def isPasswordAlreadyUsed(self, password):