enable support for passing the ICEAUTHORITY shell variable to define where to create the ice auth file
diff -r -u xfce4-session-4.4.3.orig/xfce4-session/main.c xfce4-session-4.4.3/xfce4-session/main.c
--- xfce4-session-4.4.3.orig/xfce4-session/main.c	2009-01-25 16:01:17 -0600
+++ xfce4-session-4.4.3/xfce4-session/main.c	2009-01-25 16:03:14 -0600
@@ -67,7 +67,8 @@
 {
   const gchar *lang;
   const gchar *sm;
-  gchar       *authfile;
+  gchar       *authfile = NULL;
+  int          staticauthfile = TRUE;
   int          fd;
 
   /* check that no other session manager is running */  
@@ -94,7 +95,13 @@
     }
 
   /* check access to $HOME/.ICEauthority */
-  authfile = xfce_get_homefile (".ICEauthority", NULL);
+  authfile = g_getenv ("ICEAUTHORITY");
+
+  if (authfile == NULL){
+  	authfile = xfce_get_homefile (".ICEauthority", NULL);
+  	staticauthfile = FALSE;
+  }
+
   fd = open (authfile, O_RDWR | O_CREAT, 0600);
   if (fd < 0)
     {
@@ -102,7 +109,7 @@
                authfile, g_strerror (errno));
       exit (EXIT_FAILURE);
     }
-  g_free (authfile);
+  if (staticauthfile && authfile) g_free (authfile);
   close (fd);
 }