Clear some global variables for android

src/guiengine/engine.cpp

@@ -1037,6 +1037,19 @@ namespace GUIEngine
         g_loaded_screens.clearAndDeleteAll();
     }   // deallocate
 
+    // -----------------------------------------------------------------------
+    void resetGlobalVariables()
+    {
+        // Try to clear global variable for android to avoid crashes
+        needsUpdate.m_contents_vector.clear();
+        g_loaded_screens.m_contents_vector.clear();
+        g_current_screen = NULL;
+        gui_messages.clear();
+#ifdef ANDROID
+        m_gui_functions.clear();
+#endif
+    }   // resetGlobalVariables
+
     // -----------------------------------------------------------------------
     void init(IrrlichtDevice* device_a, IVideoDriver* driver_a,
               AbstractStateManager* state_manager, bool loading)

src/guiengine/engine.hpp

@@ -116,6 +116,7 @@ namespace GUIEngine
 
     void deallocate();
 
+    void resetGlobalVariables();
 
     /**
       * \return the irrlicht device object

src/main.cpp

@@ -1701,6 +1701,8 @@ void clearGlobalVariables()
 #ifdef ENABLE_WIIUSE
     wiimote_manager = NULL;
 #endif
+    World::setWorld(NULL);
+    GUIEngine::resetGlobalVariables();
 }   // clearGlobalVariables
 
 //=============================================================================