This patch ensures '.desktop' files are picked up in the system profile
and not in the directories listed in $XDG_DATA_DIRS.  The latter includes
'gnome-session.desktop', which should be used if it's in
/run/current-system/profile, and only then.

Fixes <https://bugs.gnu.org/37831>.

diff --git a/daemon/gdm-session.c b/daemon/gdm-session.c
index 6a116a8..02c1458 100644
--- a/daemon/gdm-session.c
+++ b/daemon/gdm-session.c
@@ -348,24 +348,18 @@ get_system_session_dirs (GdmSession *self)
         GArray *search_array = NULL;
         char **search_dirs;
         int i;
-        const gchar * const *system_data_dirs = g_get_system_data_dirs ();
 
         static const char *x_search_dirs[] = {
                 "/etc/X11/sessions/",
                 DMCONFDIR "/Sessions/",
                 DATADIR "/gdm/BuiltInSessions/",
-                DATADIR "/xsessions/",
+                "/run/current-system/profile/share/xsessions/"
         };
 
         static const char *wayland_search_dir = DATADIR "/wayland-sessions/";
 
         search_array = g_array_new (TRUE, TRUE, sizeof (char *));
 
-        for (i = 0; system_data_dirs[i]; i++) {
-                gchar *dir = g_build_filename (system_data_dirs[i], "xsessions", NULL);
-                g_array_append_val (search_array, dir);
-        }
-
         g_array_append_vals (search_array, x_search_dirs, G_N_ELEMENTS (x_search_dirs));
 
 #ifdef ENABLE_WAYLAND_SUPPORT
@@ -373,16 +367,7 @@ get_system_session_dirs (GdmSession *self)
 #ifdef ENABLE_USER_DISPLAY_SERVER
                 g_array_prepend_val (search_array, wayland_search_dir);
 
-                for (i = 0; system_data_dirs[i]; i++) {
-                        gchar *dir = g_build_filename (system_data_dirs[i], "wayland-sessions", NULL);
-                        g_array_insert_val (search_array, i, dir);
-                }
 #else
-                for (i = 0; system_data_dirs[i]; i++) {
-                        gchar *dir = g_build_filename (system_data_dirs[i], "wayland-sessions", NULL);
-                        g_array_append_val (search_array, dir);
-                }
-
                 g_array_append_val (search_array, wayland_search_dir);
 #endif
         }
diff --git a/libgdm/gdm-sessions.c b/libgdm/gdm-sessions.c
index afbc5c0..bb5e3e6 100644
--- a/libgdm/gdm-sessions.c
+++ b/libgdm/gdm-sessions.c
@@ -238,19 +238,11 @@ collect_sessions (void)
                 "/etc/X11/sessions/",
                 DMCONFDIR "/Sessions/",
                 DATADIR "/gdm/BuiltInSessions/",
-                DATADIR "/xsessions/",
-                NULL
+                "/run/current-system/profile/share/xsessions/"
         };
 
         xorg_search_array = g_array_new (TRUE, TRUE, sizeof (char *));
 
-        const gchar * const *system_data_dirs = g_get_system_data_dirs ();
-
-        for (i = 0; system_data_dirs[i]; i++) {
-                session_dir = g_build_filename (system_data_dirs[i], "xsessions", NULL);
-                g_array_append_val (xorg_search_array, session_dir);
-        }
-
         g_array_append_vals (xorg_search_array, xorg_search_dirs, G_N_ELEMENTS (xorg_search_dirs));
 
 #ifdef ENABLE_WAYLAND_SUPPORT
@@ -261,11 +253,6 @@ collect_sessions (void)
 
         wayland_search_array = g_array_new (TRUE, TRUE, sizeof (char *));
 
-        for (i = 0; system_data_dirs[i]; i++) {
-                session_dir = g_build_filename (system_data_dirs[i], "wayland-sessions", NULL);
-                g_array_append_val (wayland_search_array, session_dir);
-        }
-
         g_array_append_vals (wayland_search_array, wayland_search_dirs, G_N_ELEMENTS (wayland_search_dirs));
 #endif