Initialize COM for application-owned Wine accessibility objects

tests/menu_fixture.c

@@ -1,13 +1,34 @@
 // SPDX-License-Identifier: LGPL-2.1-or-later
+#define COBJMACROS
 #include <windows.h>
+#include <initguid.h>
+#include <oleacc.h>
 
 static HMENU bar, file, edit, nested, context;
 static int step;
+static HWND marshaledControl;
+static HWND button;
+
+static LRESULT CALLBACK provider_proc(HWND window, UINT message, WPARAM wp, LPARAM lp) {
+  if (message == WM_GETOBJECT && (LONG)lp == OBJID_CLIENT) {
+    IAccessible *accessible = NULL;
+    if (SUCCEEDED(CreateStdAccessibleObject(window, OBJID_CLIENT, &IID_IAccessible,
+                                             (void **)&accessible))) {
+      // Returning a marshaled object forces the separate helper to use COM,
+      // rather than Wine's directly constructed native-control proxy.
+      LRESULT result = LresultFromObject(&IID_IAccessible, wp, (IUnknown *)accessible);
+      IAccessible_Release(accessible);
+      return result;
+    }
+  }
+  return DefWindowProcW(window, message, wp, lp);
+}
 
 static LRESULT CALLBACK window_proc(HWND window, UINT message, WPARAM wp, LPARAM lp) {
   if (message == WM_TIMER) {
     switch (++step) {
     case 1:
+      SetFocus(button);
       // Enter File through the application's actual native menu loop.
       PostMessageW(window, WM_SYSCOMMAND, SC_KEYMENU, 'f');
       break;
@@ -73,6 +94,7 @@ static LRESULT CALLBACK window_proc(HWND window, UINT message, WPARAM wp, LPARAM
 
 int WINAPI WinMain(HINSTANCE instance, HINSTANCE previous, LPSTR args, int show) {
   (void)previous; (void)args; (void)show;
+  if (FAILED(CoInitializeEx(NULL, COINIT_APARTMENTTHREADED))) return 1;
   WNDCLASSW cls = {0};
   cls.hInstance = instance;
   cls.lpszClassName = L"WineAccessMenuFixture";
@@ -92,15 +114,24 @@ int WINAPI WinMain(HINSTANCE instance, HINSTANCE previous, LPSTR args, int show)
   HWND window = CreateWindowW(cls.lpszClassName, L"Wine menu fixture", WS_OVERLAPPEDWINDOW,
                                120, 120, 400, 240, NULL, bar, instance, NULL);
   ShowWindow(window, SW_SHOW);
-  HWND button = CreateWindowW(L"Button", L"Return to control", WS_CHILD | WS_VISIBLE | WS_TABSTOP,
+  button = CreateWindowW(L"Button", L"Return to control", WS_CHILD | WS_VISIBLE | WS_TABSTOP,
                                10, 10, 200, 30, window, NULL, instance, NULL);
+  cls.lpszClassName = L"WineAccessMarshaledFixture";
+  cls.lpfnWndProc = provider_proc;
+  RegisterClassW(&cls);
+  marshaledControl = CreateWindowW(cls.lpszClassName, L"Application-owned accessibility",
+                                    WS_CHILD | WS_VISIBLE | WS_TABSTOP,
+                                    10, 60, 250, 30, window, NULL, instance, NULL);
   SetForegroundWindow(window);
   SetFocus(button);
+  SetFocus(marshaledControl);
+  NotifyWinEvent(EVENT_OBJECT_FOCUS, marshaledControl, OBJID_CLIENT, CHILDID_SELF);
   SetTimer(window, 1, 400, NULL);
   MSG message;
   while (GetMessageW(&message, NULL, 0, 0) > 0) {
     TranslateMessage(&message); DispatchMessageW(&message);
   }
   DestroyMenu(context);
+  CoUninitialize();
   return 0;
 }