[gdm/rhel-7.9: 3/51] worker: add compat patch to make new worker work with old daemon

[Ray Strode <halfline src gnome org>]

commit 3e601bcc085bd82f3e8e70d34c7bc518ce3e8a91
Author: Ray Strode <rstrode redhat com>
Date:   Mon Apr 12 16:57:49 2021 -0400

    worker: add compat patch to make new worker work with old daemon

 daemon/gdm-session-worker.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
---
diff --git a/daemon/gdm-session-worker.c b/daemon/gdm-session-worker.c
index 10ecccb07..f71594c22 100644
--- a/daemon/gdm-session-worker.c
+++ b/daemon/gdm-session-worker.c
@@ -3167,6 +3167,21 @@ gdm_session_worker_handle_setup_for_program (GdmDBusWorker         *object,
         return TRUE;
 }
 
+static void
+fix_environment_if_old_gdm_daemon_running (GdmSessionWorker *worker)
+{
+        const char *daemon_version;
+        const char *username;
+
+        daemon_version = gdm_session_worker_get_environment_variable (worker, "GDM_VERSION");
+        username = gdm_session_worker_get_environment_variable (worker, "USERNAME");
+
+        if (g_strcmp0 (daemon_version, "3.14.2") == 0 &&
+            g_strcmp0 (username, "gdm") == 0) {
+            gdm_session_worker_set_environment_variable (worker, "GNOME_SHELL_SESSION_MODE", "gdm");
+        }
+}
+
 static gboolean
 gdm_session_worker_handle_start_program (GdmDBusWorker         *object,
                                          GDBusMethodInvocation *invocation,
@@ -3176,6 +3191,8 @@ gdm_session_worker_handle_start_program (GdmDBusWorker         *object,
         GError *parse_error = NULL;
         validate_state_change (worker, invocation, GDM_SESSION_WORKER_STATE_SESSION_STARTED);
 
+        fix_environment_if_old_gdm_daemon_running (worker);
+
         if (worker->priv->is_reauth_session) {
                 g_dbus_method_invocation_return_error (invocation,
                                                        GDM_SESSION_WORKER_ERROR,