Avoid generating wxEVT_MENU_OPEN and CLOSE for disabled menus in wxMSW.

Check if a top level menu is disabled and consume WM_[UN]INITMENUPOPUP that
Windows still generates for it when it's clicked for some reason.

Closes #2168.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77657 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/frame.cpp

@@ -990,6 +990,47 @@ WXLRESULT wxFrame::MSWWindowProc(WXUINT message, WXWPARAM wParam, WXLPARAM lPara
             }
             break;
 #endif // !__WXMICROWIN__
+
+#if wxUSE_MENUS
+        case WM_INITMENUPOPUP:
+            {
+                wxMenuBar* const bar = GetMenuBar();
+                if ( bar && !bar->IsEnabledTop(LOWORD(lParam)) )
+                {
+                    // Skip sending of wxEVT_MENU_OPEN in the base class
+                    // MSWWindowProc() for disabled top level menus.
+                    return MSWDefWindowProc(message, wParam, lParam);
+                }
+            }
+            break;
+
+        case WM_UNINITMENUPOPUP:
+            {
+                wxMenuBar* const bar = GetMenuBar();
+                if ( !bar )
+                    break;
+
+                // Unlike in WM_INITMENUPOPUP above, we don't have the position
+                // of the menu in the message itself, so find it ourselves.
+                const HMENU hmenu = (HMENU)wParam;
+
+                const size_t count = bar->GetMenuCount();
+                for ( size_t n = 0; n < count; n++ )
+                {
+                    wxMenu* const menu = bar->GetMenu(n);
+                    if ( GetHmenuOf(menu) == hmenu )
+                    {
+                        if ( !bar->IsEnabledTop(n) )
+                        {
+                            // If we skipped sending wxEVT_MENU_OPEN, don't
+                            // send wxEVT_MENU_CLOSE neither.
+                            return MSWDefWindowProc(message, wParam, lParam);
+                        }
+                    }
+                }
+            }
+            break;
+#endif // wxUSE_MENUS
     }
 #if wxUSE_TASKBARBUTTON
     if ( message == wxMsgTaskbarButtonCreated )