Auth/Default: Set $session->idp on unsolicited authentication.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2250 44740490-163a-0410-bde0-09ae8108e29a

lib/SimpleSAML/Auth/Default.php

@@ -233,6 +233,12 @@ class SimpleSAML_Auth_Default {
 			$session->setLogoutState($state['LogoutState']);
 		}
 
+		if (array_key_exists('IdP', $state)) {
+			$session->setIdP($state['IdP']);
+		} else {
+			$session->setIdP(NULL);
+		}
+
 		SimpleSAML_Utilities::redirect($redirectTo);
 	}