gdbus, tests, win32: test session dbus autolaunch

The test performs implicit autolaunching of a bus
and checks if it is connectible.

In build the test is moved from "only non-windows with have_dbus_daemon"
to "anywhere".

This is intentional: actually it doesn't execute any external
binaries on unix (so doesn't require dbus_daemon)
and now has win32 implementation.

The test has some problems that are not problems of test itself,
but are reasoned by current win32 implementation:

 - since the implementation uses global win32 kernel objects
with fixed names not depending on g_get_user_runtime_dir or other context
if preexisting bus running by some other libgio-using application
the test would silently pass.

 - since the implementation uses problematic time-based synchronization,
that has a race condition between opening and reading mmaped address,
the test may randomly fail (I'd not seen this in practice).

 - since the implementation autolaunched process works for 3 seconds
after last client disconnects, the executed subprocess runs for 3 seconds
after test exit, maybe locking the libgio-2.0-0.dll file for that time.

gio/tests/gdbus-address-get-session.c

@@ -18,9 +18,12 @@
 
 #include <glib.h>
 
-#ifndef G_OS_UNIX
-#error This is a Unix-specific test
-#endif
+/* This test does NOT depend on any dbus binaries preinstalled on test host.
+ * On Unix it uses mock environment (test_xdg_runtime)
+ * or mock dbus-launch binary (test_x11_autolaunch).
+ * On Windows it relies on the fact that libgio provides
+ * internal session dbus-server on win32.
+ */
 
 #include <errno.h>
 
@@ -43,6 +46,8 @@ print_address (void)
   g_free (addr);
 }
 
+#ifdef G_OS_UNIX
+
 static GSocket *mock_bus = NULL;
 static gchar *mock_bus_path = NULL;
 /* this is deliberately something that needs escaping */
@@ -166,14 +171,57 @@ test_xdg_runtime (void)
   g_test_trap_assert_passed ();
 }
 
+#endif
+
+#ifdef G_OS_WIN32
+static void
+check_and_cleanup_autolaunched_win32_bus (void)
+{
+  /* win32 autostarted bus runs infinitely if no client ever connected.
+   * However it exits in several seconds if the last client disconnects.
+   * _This_ test only checks successful launching and connectivity,
+   * and don't bother on bus termination behavior (being it a bug or not).
+   * So connect+disconnect here is not only connectivity test,
+   * but also the workaround the bus process infinite run.
+   */
+  GError *err = NULL;
+  GDBusConnection *bus = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &err);
+  g_assert_no_error (err);
+  g_object_unref (bus);
+}
+
+static void
+test_win32_autolaunch (void)
+{
+  if (g_test_subprocess ())
+    {
+      print_address ();
+
+      check_and_cleanup_autolaunched_win32_bus ();
+      return;
+    }
+
+  g_test_trap_subprocess (NULL, 0, 0);
+  /* stderr is not checked: coverage prints warnings there */
+  g_test_trap_assert_stdout ("nonce-tcp:host=localhost,port=*,noncefile=*\\gdbus-nonce-file-*\n");
+  g_test_trap_assert_passed ();
+}
+#endif
+
 int
 main (int   argc,
       char *argv[])
 {
   g_test_init (&argc, &argv, NULL);
 
+#ifdef G_OS_UNIX
   g_test_add_func ("/gdbus/x11-autolaunch", test_x11_autolaunch);
   g_test_add_func ("/gdbus/xdg-runtime", test_xdg_runtime);
+#endif
 
-  return g_test_run();
+#ifdef G_OS_WIN32
+  g_test_add_func ("/gdbus/win32-autolaunch", test_win32_autolaunch);
+#endif
+
+  return g_test_run ();
 }

gio/tests/meson.build

@@ -78,6 +78,7 @@ gio_tests = {
   'tls-certificate' : {'extra_sources' : ['gtesttlsbackend.c']},
   'tls-interaction' : {'extra_sources' : ['gtesttlsbackend.c']},
   'tls-database' : {'extra_sources' : ['gtesttlsbackend.c']},
+  'gdbus-address-get-session' : {},
 }
 
 test_extra_programs = {
@@ -283,7 +284,6 @@ if host_machine.system() != 'windows'
                     '-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_36'],
       },
       'gapplication' : {'extra_sources' : extra_sources},
-      'gdbus-address-get-session' : {},
     }
 
     if not glib_have_cocoa