File lightdm-xauthlocalhostname-support.patch of Package lightdm

set XAUTHLOCALHOSTNAME to localhost for local logins to avoid issues in the session in case the hostname changes

diff --git a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -50,6 +50,8 @@ lightdm_SOURCES = \
 	session.h \
 	session-child.c \
 	session-child.h \
+	util.c \
+	util.h \
 	vnc-server.c \
 	vnc-server.h \
 	vt.c \
diff --git a/src/seat-xlocal.c b/src/seat-xlocal.c
--- a/src/seat-xlocal.c
+++ b/src/seat-xlocal.c
@@ -16,6 +16,7 @@
 #include "xserver-local.h"
 #include "xsession.h"
 #include "vt.h"
+#include "util.h"
 
 G_DEFINE_TYPE (SeatXLocal, seat_xlocal, SEAT_TYPE);
 
@@ -134,14 +135,17 @@ seat_xlocal_set_active_display (Seat *se
 static void
 seat_xlocal_run_script (Seat *seat, Display *display, Process *script)
 {
-    gchar *path;
+    gchar *path, *hostname;
     XServerLocal *xserver;
 
     xserver = XSERVER_LOCAL (display_get_display_server (display));
     path = xserver_local_get_authority_file_path (xserver);
+    hostname = lightdm_gethostname ();
     process_set_env (script, "DISPLAY", xserver_get_address (XSERVER (xserver)));
     process_set_env (script, "XAUTHORITY", path);
+    process_set_env (script, "XAUTHLOCALHOSTNAME", hostname);
     g_free (path);
+    g_free (hostname);
 
     SEAT_CLASS (seat_xlocal_parent_class)->run_script (seat, display, script);
 }
diff --git a/src/util.c b/src/util.c
new file mode 100644
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,14 @@
+#include <unistd.h>
+#include <limits.h>
+#include <glib.h>
+
+gchar *
+lightdm_gethostname (void)
+{
+    gchar hostname[HOST_NAME_MAX + 1];
+
+    if (gethostname (hostname, HOST_NAME_MAX) == 0)
+        return g_strdup (hostname);
+
+    return g_strdup ("localhost");
+}
diff --git a/src/util.h b/src/util.h
new file mode 100644
--- /dev/null
+++ b/src/util.h
@@ -0,0 +1,3 @@
+#include <glib.h>
+
+gchar * lightdm_gethostname (void);
diff --git a/src/xserver-local.c b/src/xserver-local.c
--- a/src/xserver-local.c
+++ b/src/xserver-local.c
@@ -21,6 +21,7 @@
 #include "process.h"
 #include "vt.h"
 #include "plymouth.h"
+#include "util.h"
 
 struct XServerLocalPrivate
 {
@@ -397,7 +398,7 @@ xserver_local_start (DisplayServer *disp
     XServerLocal *server = XSERVER_LOCAL (display_server);
     gboolean result;
     gchar *filename, *dir, *absolute_command;
-    gchar hostname[1024], *number;
+    gchar *hostname, *number;
     GString *command;
 
     g_return_val_if_fail (server->priv->xserver_process == NULL, FALSE);
@@ -438,11 +439,13 @@ xserver_local_start (DisplayServer *disp
     if (server->priv->layout)
         g_string_append_printf (command, " -layout %s", server->priv->layout);
 
-    gethostname (hostname, 1024);
+    hostname = lightdm_gethostname ();
+
     number = g_strdup_printf ("%d", xserver_get_display_number (XSERVER (server)));
     if (!server->priv->xdmcp_key)
         xserver_set_authority (XSERVER (server), xauth_new_cookie (XAUTH_FAMILY_LOCAL, (guint8*) hostname, strlen (hostname), number));
     g_free (number);
+    g_free (hostname);
     write_authority_file (server);
     if (server->priv->authority_file)
     {
diff --git a/src/xsession.c b/src/xsession.c
--- a/src/xsession.c
+++ b/src/xsession.c
@@ -15,8 +15,10 @@
 #include <sys/stat.h>
 
 #include "xsession.h"
+#include "xserver-local.h"
 #include "configuration.h"
 #include "privileges.h"
+#include "util.h"
 
 struct XSessionPrivate
 {
@@ -35,6 +37,12 @@ xsession_new (XServer *xserver)
     session = g_object_new (XSESSION_TYPE, NULL);
     session->priv->xserver = g_object_ref (xserver);
 
+    if (IS_XSERVER_LOCAL (XSESSION (session)->priv->xserver))
+    {
+        gchar *hostname = lightdm_gethostname ();
+        session_set_env (SESSION (session), "XAUTHLOCALHOSTNAME", hostname);
+        g_free (hostname);
+    }
     session_set_env (SESSION (session), "DISPLAY", xserver_get_address (xserver));
     session_set_tty (SESSION (session), xserver_get_address (xserver));
     session_set_xdisplay (SESSION (session), xserver_get_address (xserver));