[gdm] manager: fix up support for chooser

[Ray Strode <halfline src gnome org>]

commit deff5b28f8c3c27c6fe132e8e648030322b9ee77
Author: Ray Strode <rstrode redhat com>
Date:   Fri Mar 31 14:54:44 2017 -0400

    manager: fix up support for chooser
    
    We were missing some chunks of code to handle dealing with
    the chooser.
    
    This commit adds in the necessary bits to start the chooser,
    and deal with the choice.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780787

 daemon/gdm-manager.c |   62 ++++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 53 insertions(+), 9 deletions(-)
---
diff --git a/daemon/gdm-manager.c b/daemon/gdm-manager.c
index 8169f2b..2b5350e 100644
--- a/daemon/gdm-manager.c
+++ b/daemon/gdm-manager.c
@@ -45,6 +45,7 @@
 #include "gdm-manager-glue.h"
 #include "gdm-display-store.h"
 #include "gdm-display-factory.h"
+#include "gdm-launch-environment.h"
 #include "gdm-local-display.h"
 #include "gdm-local-display-factory.h"
 #include "gdm-session.h"
@@ -52,6 +53,7 @@
 #include "gdm-settings-direct.h"
 #include "gdm-settings-keys.h"
 #include "gdm-xdmcp-display-factory.h"
+#include "gdm-xdmcp-chooser-display.h"
 
 #define GDM_MANAGER_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GDM_TYPE_MANAGER, GdmManagerPrivate))
 
@@ -820,7 +822,7 @@ gdm_manager_handle_open_session (GdmDBusManager        *manager,
         const char       *sender;
         GDBusConnection  *connection;
         GdmDisplay       *display = NULL;
-        GdmSession       *session;
+        GdmSession       *session = NULL;
         const char       *address;
         GPid              pid = 0;
         uid_t             uid = (uid_t) -1;
@@ -841,14 +843,32 @@ gdm_manager_handle_open_session (GdmDBusManager        *manager,
                 return TRUE;
         }
 
-        session = get_embryonic_user_session_for_display (display);
+        if (GDM_IS_XDMCP_CHOOSER_DISPLAY (display)) {
+                GdmLaunchEnvironment *launch_environment;
 
-        if (gdm_session_is_running (session)) {
-                g_dbus_method_invocation_return_error_literal (invocation,
-                                                               G_DBUS_ERROR,
-                                                               G_DBUS_ERROR_ACCESS_DENIED,
-                                                               _("Can only be called before user is logged 
in"));
-                return TRUE;
+                g_object_get (display, "launch-environment", &launch_environment, NULL);
+
+                if (launch_environment != NULL) {
+                        session = gdm_launch_environment_get_session (launch_environment);
+                }
+
+                if (session == NULL) {
+                        g_dbus_method_invocation_return_error_literal (invocation,
+                                                                       G_DBUS_ERROR,
+                                                                       G_DBUS_ERROR_ACCESS_DENIED,
+                                                                       _("Chooser session unavailable"));
+                        return TRUE;
+                }
+        } else {
+                session = get_embryonic_user_session_for_display (display);
+
+                if (gdm_session_is_running (session)) {
+                        g_dbus_method_invocation_return_error_literal (invocation,
+                                                                       G_DBUS_ERROR,
+                                                                       G_DBUS_ERROR_ACCESS_DENIED,
+                                                                       _("Can only be called before user is 
logged in"));
+                        return TRUE;
+                }
         }
 
         allowed_user = gdm_session_get_allowed_user (session);
@@ -1336,6 +1356,26 @@ set_up_automatic_login_session (GdmManager *manager,
 }
 
 static void
+set_up_chooser_session (GdmManager *manager,
+                        GdmDisplay *display)
+{
+        const char *allowed_user;
+        struct passwd *passwd_entry;
+
+        allowed_user = get_username_for_greeter_display (manager, display);
+
+        if (!gdm_get_pwent_for_name (allowed_user, &passwd_entry)) {
+                g_warning ("GdmManager: couldn't look up username %s",
+                           allowed_user);
+                gdm_display_unmanage (display);
+                gdm_display_finish (display);
+                return;
+        }
+
+        gdm_display_start_greeter_session (display);
+}
+
+static void
 set_up_greeter_session (GdmManager *manager,
                         GdmDisplay *display)
 {
@@ -1410,7 +1450,11 @@ set_up_session (GdmManager *manager,
                 autologin_enabled = get_automatic_login_details (manager, &username);
 
         if (!autologin_enabled) {
-                set_up_greeter_session (manager, display);
+                if (GDM_IS_XDMCP_CHOOSER_DISPLAY (display)) {
+                        set_up_chooser_session (manager, display);
+                } else {
+                        set_up_greeter_session (manager, display);
+                }
                 g_free (username);
                 return;
         }