SpringSource/spring-webflow-samples — pull request #15 by danielfernandez (2013-06-09 21:46:26+00:00)
Title: Fixed parsing error on login error

This pull request fixes the possibility of receiving an expression parsing error when:

* Bad login credentials have been input, and we're being shown the login error page.
* Session expires
* We hit F5

The error is due to the `session` variables map (containing the *session attributes*) not being checked for nullity when an `HttpSession` has not been initialized (or has expired).