[gdm] session: reset session type to default when selecting non-wayland session

[Ray Strode <halfline src gnome org>]

commit 4e68490ff423cf27c0a00176ba4f75b17406d2a5
Author: Ray Strode <rstrode redhat com>
Date:   Thu Feb 26 10:07:53 2015 -0500

    session: reset session type to default when selecting non-wayland session
    
    If we select a non-wayland session we need to clear the session type,
    or it will linger as a wayland session if it was one previously.
    
    Prevents users from getting logged into an X session when with
    XDG_SESSION_TYPE=wayland.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=745235

 daemon/gdm-session.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gdm-session.c b/daemon/gdm-session.c
index ad42b5b..c66a6ff 100644
--- a/daemon/gdm-session.c
+++ b/daemon/gdm-session.c
@@ -2999,6 +2999,8 @@ gdm_session_select_session (GdmSession *self,
         is_wayland_session = gdm_session_is_wayland_session (self);
         if (is_wayland_session) {
                 set_session_type (self, "wayland");
+        } else {
+                set_session_type (self, NULL);
         }
 #endif