tests: Add drm lease test for non non-desktop hotplugs

This tests that https://gitlab.gnome.org/GNOME/mutter/-/issues/3943
doesn't reproduce by triggering hotplugs in a certain way.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4378>

src/backends/meta-backend-private.h

@@ -261,6 +261,12 @@ void meta_backend_update_from_event (MetaBackend  *backend,
 char * meta_backend_get_vendor_name (MetaBackend *backend,
                                      const char  *pnp_id);
 
+META_EXPORT_TEST
+void meta_backend_pause (MetaBackend *backend);
+
+META_EXPORT_TEST
+void meta_backend_resume (MetaBackend *backend);
+
 META_EXPORT_TEST
 uint32_t meta_clutter_button_to_evdev (uint32_t clutter_button);
 

src/backends/meta-backend.c

@@ -975,7 +975,7 @@ meta_backend_class_init (MetaBackendClass *klass)
 }
 
 #ifdef HAVE_LOGIND
-static void
+void
 meta_backend_pause (MetaBackend *backend)
 {
   COGL_TRACE_BEGIN_SCOPED (MetaBackendPause,
@@ -984,7 +984,7 @@ meta_backend_pause (MetaBackend *backend)
   META_BACKEND_GET_CLASS (backend)->pause (backend);
 }
 
-static void
+void
 meta_backend_resume (MetaBackend *backend)
 {
   COGL_TRACE_BEGIN_SCOPED (MetaBackendResume,

src/tests/drm-lease-monitor-test.c

@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2025 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+
+#include "backends/meta-monitor-config-manager.h"
+#include "backends/native/meta-backend-native.h"
+#include "backends/native/meta-kms.h"
+#include "backends/native/meta-kms-device.h"
+#include "meta-test/meta-context-test.h"
+#include "tests/drm-mock/drm-mock.h"
+#include "tests/meta-test-utils.h"
+
+static MetaContext *test_context;
+
+static void
+fake_udev_hotplug (void)
+{
+  MetaBackend *backend = meta_context_get_backend (test_context);
+  MetaUdev *udev = meta_backend_get_udev (backend);
+  g_autolist (GUdevDevice) devices = NULL;
+  g_autoptr (GError) error = NULL;
+  GList *l;
+
+  devices = meta_udev_list_drm_devices (udev,
+                                        META_UDEV_DEVICE_TYPE_CARD,
+                                        &error);
+  g_assert_no_error (error);
+  g_assert_nonnull (devices);
+
+  for (l = devices; l; l = l->next)
+    {
+      GUdevDevice *device = l->data;
+
+      g_signal_emit_by_name (udev, "hotplug", device);
+    }
+}
+
+static void
+disconnect_connector_filter (gpointer resource,
+                             gpointer user_data)
+{
+  drmModeConnector *drm_connector = resource;
+
+  drm_connector->connection = DRM_MODE_DISCONNECTED;
+}
+
+static void
+test_drm_lease_lease_suspend_resume (void)
+{
+  MetaBackend *backend = meta_context_get_backend (test_context);
+
+  meta_backend_pause (backend);
+  drm_mock_set_resource_filter (DRM_MOCK_CALL_FILTER_GET_CONNECTOR,
+                                disconnect_connector_filter, NULL);
+  fake_udev_hotplug ();
+  meta_backend_resume (backend);
+
+  drm_mock_unset_resource_filter (DRM_MOCK_CALL_FILTER_GET_CONNECTOR);
+  fake_udev_hotplug ();
+}
+
+static void
+init_tests (void)
+{
+  g_test_add_func ("/wayland/drm-lease/suspend-resume",
+                   test_drm_lease_lease_suspend_resume);
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+  g_autoptr (MetaContext) context = NULL;
+
+  context = meta_create_test_context (META_CONTEXT_TEST_TYPE_VKMS,
+                                      META_CONTEXT_TEST_FLAG_NO_X11);
+  g_assert_true (meta_context_configure (context, &argc, &argv, NULL));
+
+  test_context = context;
+
+  init_tests ();
+
+  return meta_context_test_run_tests (META_CONTEXT_TEST (context),
+                                      META_TEST_RUN_FLAG_CAN_SKIP);
+}

src/tests/meson.build

@@ -708,6 +708,13 @@ kms_test_cases = [
       wayland_test_utils,
     ],
   },
+  {
+    'name': 'drm-lease-monitor',
+    'suite': 'backends/native',
+    'sources': [
+      'drm-lease-monitor-test.c',
+    ],
+  },
 ]
 
 privileged_test_cases += kms_test_cases