tests: Add test case for keybinding remove race

When a key binding is removed, and a trigger key sequence is dispatched
before the idle callback that resolves and updates the actual binding,
we should handle that gracefully.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3711>

src/tests/keybindings.c

@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2024 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 <linux/input-event-codes.h>
+
+#include "backends/meta-backend-private.h"
+#include "meta/keybindings.h"
+#include "meta-test/meta-context-test.h"
+#include "tests/meta-test-utils.h"
+
+static MetaContext *test_context;
+
+static void
+test_handler (MetaDisplay           *display,
+              MetaWindow            *window,
+              const ClutterKeyEvent *event,
+              MetaKeyBinding        *binding,
+              gpointer               user_data)
+{
+  gboolean *triggered = user_data;
+
+  *triggered = TRUE;
+}
+
+static gboolean
+set_true_cb (gpointer user_data)
+{
+  gboolean *done = user_data;
+
+  *done = TRUE;
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+test_keybinding_remove_trigger (void)
+{
+  MetaDisplay *display = meta_context_get_display (test_context);
+  MetaBackend *backend = meta_context_get_backend (test_context);
+  ClutterSeat *seat;
+  g_autoptr (GSettings) settings = NULL;
+  g_autoptr (ClutterVirtualInputDevice) virtual_keyboard = NULL;
+  gboolean triggered = FALSE;
+  gboolean done = FALSE;
+
+  seat = meta_backend_get_default_seat (backend);
+  virtual_keyboard = clutter_seat_create_virtual_device (seat,
+                                                         CLUTTER_KEYBOARD_DEVICE);
+
+  settings = g_settings_new ("org.gnome.mutter.test");
+  meta_display_add_keybinding (display,
+                               "test-binding",
+                               settings,
+                               META_KEY_BINDING_NONE,
+                               test_handler,
+                               &triggered, NULL);
+
+  g_idle_add_full (G_PRIORITY_LOW,
+                   set_true_cb,
+                   &done,
+                   NULL);
+  while (!done)
+    g_main_context_iteration (NULL, TRUE);
+
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_LEFTMETA,
+                                           CLUTTER_KEY_STATE_PRESSED);
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_T,
+                                           CLUTTER_KEY_STATE_PRESSED);
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_T,
+                                           CLUTTER_KEY_STATE_RELEASED);
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_LEFTMETA,
+                                           CLUTTER_KEY_STATE_RELEASED);
+
+  while (!triggered)
+    g_main_context_iteration (NULL, TRUE);
+
+  meta_display_remove_keybinding (display, "test-binding");
+
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_LEFTMETA,
+                                           CLUTTER_KEY_STATE_PRESSED);
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_T,
+                                           CLUTTER_KEY_STATE_PRESSED);
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_T,
+                                           CLUTTER_KEY_STATE_RELEASED);
+  clutter_virtual_input_device_notify_key (virtual_keyboard,
+                                           g_get_monotonic_time (),
+                                           KEY_LEFTMETA,
+                                           CLUTTER_KEY_STATE_RELEASED);
+
+  meta_flush_input (test_context);
+  while (g_main_context_iteration (NULL, FALSE)) {}
+}
+
+static void
+init_tests (void)
+{
+  g_test_add_func ("/core/keybindings/remove-trigger", test_keybinding_remove_trigger);
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  g_autoptr (MetaContext) context = NULL;
+
+  context = meta_create_test_context (META_CONTEXT_TEST_TYPE_HEADLESS,
+                                      META_CONTEXT_TEST_FLAG_NO_X11);
+  g_assert (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_NONE);
+}

src/tests/meson.build

@@ -116,6 +116,10 @@ pkg.generate(libmutter_test,
   install_dir: pcdir,
 )
 
+gnome.compile_schemas(
+  depend_files: 'org.gnome.mutter.test.gschema.xml',
+)
+
 if have_cogl_tests
   subdir('cogl')
 endif
@@ -140,6 +144,7 @@ test_env_variables = {
   'G_TEST_BUILDDIR': mutter_builddir,
   'XDG_CONFIG_HOME': mutter_builddir / '.config',
   'MUTTER_TEST_PLUGIN_PATH': '@0@'.format(default_plugin.full_path()),
+  'GSETTINGS_SCHEMA_DIR': mutter_builddir / 'src' / 'tests',
 }
 
 foreach name, value: test_env_variables
@@ -292,6 +297,11 @@ test_cases += [
     'suite': 'unit',
     'sources': [ 'color-management-profile-conflict-test.c', ],
   },
+  {
+    'name': 'keybindings',
+    'suite': 'input',
+    'sources': [ 'keybindings.c' ],
+  },
 ]
 
 if have_native_tests

src/tests/org.gnome.mutter.test.gschema.xml

@@ -0,0 +1,14 @@
+<schemalist>
+
+  <schema id="org.gnome.mutter.test" path="/org/gnome/mutter/test/">
+
+  <key name="test-binding" type="as">
+    <default>['&lt;Super&gt;t']</default>
+      <summary>Test</summary>
+      <description>
+	Test.
+      </description>
+    </key>
+
+  </schema>
+</schemalist>