From adf12504c0477a35f84d07401fdec80a95a2521f Mon Sep 17 00:00:00 2001
From: Joan Torres <joan.torres@suse.com>
Date: Fri, 9 Jun 2023 16:19:09 +0200
Subject: [PATCH] backends/native: Set headless mode when no seat_id

This forces not using the seat_proxy. But still allows the use of
session_proxy.

On tests, headless mode is explicitly set and it might not be available a
systemd session. To avoid test failing on this situation skip using
meta_launcher wich uses session_proxy and seat_proxy.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3093>
---
 src/backends/native/meta-backend-native.c | 36 +++++++++++++----------
 src/backends/native/meta-launcher.c       | 25 +++++++++-------
 2 files changed, 34 insertions(+), 27 deletions(-)

diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index 9e8c918d4..f01890460 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -775,30 +775,34 @@ meta_backend_native_initable_init (GInitable     *initable,
   MetaBackendNative *native = META_BACKEND_NATIVE (initable);
   MetaBackend *backend = META_BACKEND (native);
   MetaKmsFlags kms_flags;
+  const char *session_id = NULL;
+  const char *seat_id = NULL;
 
-  if (!meta_backend_is_headless (backend))
+  switch (native->mode)
     {
-      const char *session_id = NULL;
-      const char *seat_id = NULL;
-
-      switch (native->mode)
-        {
-        case META_BACKEND_NATIVE_MODE_DEFAULT:
-          break;
-        case META_BACKEND_NATIVE_MODE_HEADLESS:
-          g_assert_not_reached ();
-          break;
-        case META_BACKEND_NATIVE_MODE_TEST:
-          session_id = "dummy";
-          seat_id = "seat0";
-          break;
-        }
+    case META_BACKEND_NATIVE_MODE_DEFAULT:
+      break;
+    case META_BACKEND_NATIVE_MODE_HEADLESS:
+      break;
+    case META_BACKEND_NATIVE_MODE_TEST:
+      session_id = "dummy";
+      seat_id = "seat0";
+      break;
+    }
 
+  if (native->mode != META_BACKEND_NATIVE_MODE_HEADLESS)
+    {
       native->launcher = meta_launcher_new (backend,
                                             session_id, seat_id,
                                             error);
       if (!native->launcher)
         return FALSE;
+
+      if (!meta_launcher_get_seat_id (native->launcher))
+        {
+          native->mode = META_BACKEND_NATIVE_MODE_HEADLESS;
+          g_message ("No seat assigned, running headlessly");
+        }
     }
 
   native->device_pool = meta_device_pool_new (native);
diff --git a/src/backends/native/meta-launcher.c b/src/backends/native/meta-launcher.c
index 4bc42cea4..e1c9e8e1a 100644
--- a/src/backends/native/meta-launcher.c
+++ b/src/backends/native/meta-launcher.c
@@ -409,29 +409,30 @@ meta_launcher_new (MetaBackend  *backend,
           g_clear_error (&local_error);
           seat_id = g_strdup (fallback_seat_id);
         }
-      else
-        {
-          g_propagate_error (error, local_error);
-          goto fail;
-        }
     }
 
-  seat_proxy = get_seat_proxy (seat_id, NULL, error);
-  if (!seat_proxy)
-    goto fail;
+  if (seat_id)
+    {
+      seat_proxy = get_seat_proxy (seat_id, NULL, error);
+      if (!seat_proxy)
+        goto fail;
+    }
 
   self = g_new0 (MetaLauncher, 1);
   self->backend = backend;
   self->session_proxy = g_object_ref (session_proxy);
-  self->seat_proxy = g_object_ref (seat_proxy);
-  self->seat_id = g_steal_pointer (&seat_id);
   self->session_active = TRUE;
+  if (seat_id)
+    {
+      self->seat_proxy = g_object_ref (seat_proxy);
+      self->seat_id = g_steal_pointer (&seat_id);
+    }
 
   g_signal_connect (self->session_proxy, "notify::active", G_CALLBACK (on_active_changed), self);
 
   return self;
 
- fail:
+fail:
   if (have_control)
     {
       meta_dbus_login1_session_call_release_control_sync (session_proxy,
@@ -454,6 +455,8 @@ meta_launcher_activate_vt (MetaLauncher  *launcher,
                            signed char    vt,
                            GError       **error)
 {
+  g_assert (launcher->seat_proxy);
+
   return meta_dbus_login1_seat_call_switch_to_sync (launcher->seat_proxy, vt,
                                                     NULL, error);
 }