tests: Add test for MUTTER_DEBUG_DISABLE_HW_CURSORS=1

It tests that the cursor renderer can successfully initialize with the
environment variable MUTTER_DEBUG_DISABLE_HW_CURSORS=1.

It would have caught the crash fixed by the previous commit.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4272>

src/tests/meson.build

@@ -665,6 +665,14 @@ kms_test_cases = [
     ],
     'variants': kms_test_variants,
   },
+  {
+    'name': 'kms-cursor-force-disable',
+    'suite': 'backends/native',
+    'sources': [
+      'native-kms-cursor-force-disable.c',
+      wayland_test_utils,
+    ],
+  },
   {
     'name': 'kms-cursor-hotplug',
     'suite': 'backends/native',

src/tests/native-kms-cursor-force-disable.c

@@ -0,0 +1,115 @@
+/*
+ * 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 "backends/meta-monitor-config-manager.h"
+#include "backends/meta-udev.h"
+#include "backends/meta-virtual-monitor.h"
+#include "backends/native/meta-backend-native.h"
+#include "backends/native/meta-crtc-kms.h"
+#include "backends/native/meta-crtc-virtual.h"
+#include "core/window-private.h"
+#include "meta-test/meta-context-test.h"
+#include "meta/meta-backend.h"
+#include "meta/meta-cursor-tracker.h"
+#include "tests/meta-test-utils.h"
+#include "tests/meta-wayland-test-driver.h"
+#include "tests/meta-wayland-test-utils.h"
+#include "wayland/meta-cursor-sprite-wayland.h"
+#include "wayland/meta-wayland-private.h"
+#include "wayland/meta-wayland-seat.h"
+
+static MetaContext *test_context;
+
+static void
+meta_test_cursor_force_disable (void)
+{
+  MetaBackend *backend = meta_context_get_backend (test_context);
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  MetaCursorRenderer *cursor_renderer = meta_backend_get_cursor_renderer (backend);
+  MetaWaylandCompositor *wayland_compositor =
+    meta_context_get_wayland_compositor (test_context);
+  g_autoptr (MetaWaylandTestDriver) test_driver = NULL;
+  MetaCursorSprite *cursor_sprite;
+  g_autoptr (MetaVirtualMonitorInfo) monitor_info = NULL;
+  MetaVirtualMonitor *virtual_monitor;
+  ClutterSeat *seat;
+  g_autoptr (ClutterVirtualInputDevice) virtual_pointer = NULL;
+  GError *error = NULL;
+
+  test_driver = meta_wayland_test_driver_new (wayland_compositor);
+
+  seat = meta_backend_get_default_seat (backend);
+  virtual_pointer = clutter_seat_create_virtual_device (seat,
+                                                        CLUTTER_POINTER_DEVICE);
+
+  monitor_info = meta_virtual_monitor_info_new (100, 100, 60.0,
+                                                "MetaTestVendor",
+                                                "MetaVirtualMonitor",
+                                                "0x1234");
+  virtual_monitor = meta_monitor_manager_create_virtual_monitor (monitor_manager,
+                                                                 monitor_info,
+                                                                 &error);
+  if (!virtual_monitor)
+    g_error ("Failed to create virtual monitor: %s", error->message);
+  meta_monitor_manager_reload (monitor_manager);
+
+  clutter_virtual_input_device_notify_absolute_motion (virtual_pointer,
+                                                       g_get_monotonic_time (),
+                                                       50, 50);
+
+  cursor_renderer = meta_backend_get_cursor_renderer (backend);
+
+  while (TRUE)
+    {
+      cursor_sprite = meta_cursor_renderer_get_cursor (cursor_renderer);
+      if (cursor_sprite)
+        break;
+      g_main_context_iteration (NULL, TRUE);
+    }
+  g_assert_true (cursor_sprite);
+}
+
+static void
+init_tests (void)
+{
+  g_test_add_func ("/wayland/cursor-force-disable",
+                   meta_test_cursor_force_disable);
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  g_autoptr (MetaContext) context = NULL;
+
+  g_setenv ("MUTTER_DEBUG_DISABLE_HW_CURSORS", "1", TRUE);
+
+  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);
+}