set wxWS_EX_TRANSIENT flag for splash screen to prevent it from being implicitly used as dialog parent

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@60558 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/splash.cpp

@@ -52,6 +52,10 @@ wxSplashScreen::wxSplashScreen(const wxBitmap& bitmap, long splashStyle, int mil
                                const wxSize& size, long style)
     : wxFrame(parent, id, wxEmptyString, wxPoint(0,0), wxSize(100, 100), style)
 {
+    // splash screen must not be used as parent by the other windows because it
+    // is going to disappear soon, indicate it by giving it this special style
+    SetExtraStyle(GetExtraStyle() | wxWS_EX_TRANSIENT);
+
 #if defined(__WXGTK20__)
     gtk_window_set_type_hint(GTK_WINDOW(m_widget),
                              GDK_WINDOW_TYPE_HINT_SPLASHSCREEN);