Fixed premature exit of helpview sample and utility

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44600 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/html/helpfrm.cpp

@@ -55,6 +55,7 @@
 #include "wx/fontenum.h"
 #include "wx/artprov.h"
 #include "wx/spinctrl.h"
+#include "wx/app.h"
 
 IMPLEMENT_DYNAMIC_CLASS(wxHtmlHelpFrame, wxFrame)
 
@@ -237,4 +238,11 @@ void wxHtmlHelpFrame::OnAbout(wxCommandEvent& event)
 }
 #endif
 
+// we don't want to prevent the app from closing just because a help window
+// remains opened
+bool wxHtmlHelpFrame::ShouldPreventAppExit() const
+{
+    return (this == wxTheApp->GetTopWindow());
+}
+
 #endif // wxUSE_WXHTML_HELP