// accessibility support.
const int kIdScreenReaderHoneyPot = 1;
-// A version of the OBJID_CLIENT constant that works in 64-bit mode too.
-static const LPARAM kObjIdClient = static_cast<ULONG>(OBJID_CLIENT);
-
LegacyRenderWidgetHostHWND::~LegacyRenderWidgetHostHWND() {
::DestroyWindow(hwnd());
}
LRESULT LegacyRenderWidgetHostHWND::OnGetObject(UINT message,
WPARAM w_param,
LPARAM l_param) {
- if (kIdScreenReaderHoneyPot == l_param) {
+ // Only the lower 32 bits of l_param are valid when checking the object id
+ // because it sometimes gets sign-extended incorrectly (but not always).
+ DWORD obj_id = static_cast<DWORD>(static_cast<DWORD_PTR>(l_param));
+
+ if (kIdScreenReaderHoneyPot == obj_id) {
// When an MSAA client has responded to our fake event on this id,
// enable screen reader support.
BrowserAccessibilityState::GetInstance()->OnScreenReaderDetected();
return static_cast<LRESULT>(0L);
}
- if (kObjIdClient != l_param || !manager_)
+ if (OBJID_CLIENT != obj_id || !manager_)
return static_cast<LRESULT>(0L);
base::win::ScopedComPtr<IAccessible> root(