test if wxString(NULL) ctor creates empty string

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@46255 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/strings/strings.cpp

@@ -171,6 +171,9 @@ void StringTestCase::Constructors()
     const wxChar *start = wxStrchr(s, _T('r'));
     const wxChar *end = wxStrchr(s, _T('!'));
     TEST_CTOR((start, end), _T("really"));
+
+    // test if creating string from NULL C pointer works:
+    TEST_CTOR(((char*)NULL), "");
 }