message: Add a failsafe setting into the 1.4.x lumina-desktop:
  Ensure that the lumina theme engine is always set in the session environment unless manually replaced/removed in the session settings.
diff: @@ -346,6 +346,8 @@ void LSession::watcherChange(QString changed){
  //qDebug() << "Set Qt5 theme engine: " << engine;
  if(engine.isEmpty()){ unsetenv("QT_QPA_PLATFORMTHEME"); }
  else{ setenv("QT_QPA_PLATFORMTHEME", engine.toUtf8().data(),1); }
  + }else{
  + setenv("QT_QPA_PLATFORMTHEME", "lthemeengine",1); //ensure the lumina theme engine is always enabled
  }
  emit SessionConfigChanged();
  }else if(changed.endsWith("desktopsettings.conf") ){ emit DesktopConfigChanged(); }
  