[gdm] Fix crash when face browser disabled

[Ray Strode <halfline src gnome org>]

commit 7ba85e239ad007e5f972053b43803ec8522965c9
Author: Brian Cameron <Brian Cameron oracle com>
Date:   Wed Sep 15 14:58:57 2010 -0400

    Fix crash when face browser disabled
    
    If you enter a username and an invalid password, then the dialog resets
    without an entry field and just a "Login" button.  So you can't enter
    the username.  If you click on the "Login" button then it crashes.
    
    This is because of missing code to initiate authentication.

 gui/simple-greeter/gdm-greeter-login-window.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gui/simple-greeter/gdm-greeter-login-window.c b/gui/simple-greeter/gdm-greeter-login-window.c
index 96e6fce..cd9a162 100644
--- a/gui/simple-greeter/gdm-greeter-login-window.c
+++ b/gui/simple-greeter/gdm-greeter-login-window.c
@@ -668,6 +668,11 @@ reset_dialog (GdmGreeterLoginWindow *login_window,
                 /* If we don't have a user list jump straight to authenticate */
                 g_debug ("GdmGreeterLoginWindow: jumping straight to authenticate");
                 switch_mode (login_window, MODE_AUTHENTICATION);
+
+                g_debug ("Starting PAM conversation since no local users");
+                g_signal_emit (G_OBJECT (login_window), signals[USER_SELECTED],
+                               0, GDM_USER_CHOOSER_USER_OTHER);
+                g_signal_emit (login_window, signals[BEGIN_VERIFICATION], 0);
         } else {
                 switch_mode (login_window, dialog_mode);
         }