multiple runs of QCoreApplication results in wrong QLibraryInfo paths

The Background:
I am developing a plugin which uses Qt. This plugin is not unloaded by the host system, so I run the "main" function of my plugin multiple times without reloading the dynamic libraries. This means I create/run/destroy a QCoreApplication multiple times.
Because of the directory structure in which the plugin lives I have created a qt.conf file to correctly set up the plugin folders for Qt.

I noticed the following bug in Qt:

• The first time I create and run the plugin everything works as expected.
• From the second time onwards the Qt build prefix is used and qt.conf is totally ignored

Some Source Code lookup, revealed this (qtbase/src/corelib/global/qlibraryinfo.cpp):

• When the plugin is run for the first time QLibrarySettings is constructed using the qt.conf file:

  QLibrarySettings::QLibrarySettings()
      : settings(QLibraryInfoPrivate::findConfiguration())
  

• when QCoreApplication is destructed "qt_call_post_routines()" is called, which in turn calls:

  static void cleanup()
      {
          QLibrarySettings *ls = qt_library_settings();
          if (ls)
              ls->settings.reset(0);
      }
  

• This results in a valid QLibrarySettings object (but with settings==NULL) for the second run of the plugin. So the function

  static QSettings *configuration()
      {
          QLibrarySettings *ls = qt_library_settings();
          return ls ? ls->settings.data() : 0;
      }
  

  returns a NULL pointer.

my suggestion:
changed the function to this:

static QSettings *configuration()
{ 
    QLibrarySettings *ls = qt_library_settings();
    if (!ls) return 0; 
    if (!ls->settings) ls->settings.reset(findConfiguration());
    return ls->settings.data(); 
}