Username field cleared in login screen after bad password entered? 5.x vs 6.x

[Sam Galosh]

I'm updating from cas 5.2 to 6.4 and am noticing a difference in the login screen's handling of an incorrect password.

In cas 5.2, when the user enters an invalid password the /cas/login screen is reloaded (with an appropriate message) and the username previously entered is populated in the username field. 

In cas 6.4 the username field is empty after the page refresh. 

Debugging into the code I can see that the ClearWebflowCredentialAction is executing which is clearing out the username. Is this an intentional change in CAS? Is there some way to revert to the previous behavior?

[Jason Cole]

Seeing the same in 6.6.1. Any ways to bring the old behavior back?