[gdm] session: track login session display mode separate from user sessions

[Ray Strode <halfline src gnome org>]

commit e29372cedc5acaca24b61d7a4ca4606a31ccc962
Author: Ray Strode <rstrode redhat com>
Date:   Tue Jan 20 09:05:35 2015 -0500

    session: track login session display mode separate from user sessions
    
    In the future X based user sessions will get their own VT just like
    wayland sessions do. For the time being, the login screen still needs
    to use the VT and X server set up by the slave code though.
    
    This commit makes sure that the two cases are handled distinctly, so
    down the line they can be given different values.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=744764

 daemon/gdm-session.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)
---
diff --git a/daemon/gdm-session.c b/daemon/gdm-session.c
index ec05859..627796a 100644
--- a/daemon/gdm-session.c
+++ b/daemon/gdm-session.c
@@ -124,6 +124,8 @@ struct _GdmSessionPrivate
         GDBusServer         *worker_server;
         GDBusServer         *outside_server;
         GHashTable          *environment;
+
+        gboolean             is_program_session : 1;
 };
 
 enum {
@@ -2194,6 +2196,7 @@ gdm_session_setup_for_user (GdmSession *self,
 
         gdm_session_select_user (self, username);
 
+        self->priv->is_program_session = FALSE;
         send_setup_for_user (self, service_name);
         gdm_session_defaults_changed (self);
 }
@@ -2207,6 +2210,7 @@ gdm_session_setup_for_program (GdmSession *self,
 
         g_return_if_fail (GDM_IS_SESSION (self));
 
+        self->priv->is_program_session = TRUE;
         send_setup_for_program (self, service_name, username, log_file);
 }
 
@@ -2916,6 +2920,14 @@ gdm_session_get_display_mode (GdmSession *self)
         }
 #endif
 
+        /* The X session used for the login screen uses the
+         * X server started up by the slave, so it should be
+         * reuse VT
+         */
+        if (self->priv->is_program_session) {
+                return GDM_SESSION_DISPLAY_MODE_REUSE_VT;
+        }
+
         /* X sessions are for now ran in classic mode where
          * we reuse the existing greeter. */
         return GDM_SESSION_DISPLAY_MODE_REUSE_VT;