--- data/lightdm.conf

+++ data/lightdm.conf

@@ -6,7 +6,7 @@

 # minimum-display-number = Minimum display number to use for X servers

 # minimum-vt = First VT to run displays on

 # lock-memory = True to prevent memory from being paged to disk

-# user-authority-in-system-dir = True if session authority should be in the system location

+# user-authority-in-system-dir = True if session authority should be in the system location, else XDG_RUNTIME_DIR or home dir will be used

 # guest-account-script = Script to be run to setup guest account

 # logind-check-graphical = True to on start seats that are marked as graphical by logind

 # log-directory = Directory to log information to

--- src/session-child.c

+++ src/session-child.c

@@ -602,6 +581,13 @@

     /* Write X authority */

     if (x_authority)

     {

+        /* If XDG_RUNTIME_DIR is set and user-authority-in-system-dir=false than use

+         * XDG_RUNTIME_DIR to store .Xauthority file. */

+        const gchar *runtime_dir = pam_getenv (pam_handle, "XDG_RUNTIME_DIR");

+        if (runtime_dir && x_authority_filename && g_str_has_suffix (x_authority_filename, ".Xauthority")) {

+            x_authority_filename = g_build_filename (runtime_dir, ".Xauthority", NULL);

+        }

+

         gboolean drop_privileges = geteuid () == 0;

         if (drop_privileges)

             privileges_drop (user_get_uid (user), user_get_gid (user));