Clean up wxMSW tooltip window on library shutdown

Not doing this prevented the tooltips from working correctly if the library
was shut down and reinitialized again, so add a module ensuring this is done.

Closes #17360.

include/wx/msw/tooltip.h

@@ -74,6 +74,9 @@ public:
     static void UpdateVisibility();
 
 private:
+    // This module calls our DeleteToolTipCtrl().
+    friend class wxToolTipModule;
+
     // Adds a window other than our main m_window to this tooltip.
     void DoAddHWND(WXHWND hWnd);
 
@@ -92,6 +95,9 @@ private:
     // create the tooltip ctrl if it doesn't exist yet and return its HWND
     static WXHWND GetToolTipCtrl();
 
+    // to be used in wxModule for deleting tooltip ctrl window when exiting mainloop
+    static void DeleteToolTipCtrl();
+
     // new tooltip maximum width, defaults to min(display width, 400)
     static int ms_maxWidth;
 

src/msw/tooltip.cpp

@@ -134,6 +134,30 @@ public:
     }
 };
 
+// Takes care of deleting ToolTip control window when shutting down the library.
+class wxToolTipModule : public wxModule
+{
+public:
+    wxToolTipModule()
+    {
+    }
+
+    virtual bool OnInit() wxOVERRIDE
+    {
+        return true;
+    }
+
+    virtual void OnExit() wxOVERRIDE
+    {
+        wxToolTip::DeleteToolTipCtrl();
+    }
+
+private:
+    wxDECLARE_DYNAMIC_CLASS(wxToolTipModule);
+};
+
+wxIMPLEMENT_DYNAMIC_CLASS(wxToolTipModule, wxModule);
+
 #ifdef __VISUALC__
     #pragma warning( default : 4097 )
 #endif
@@ -253,6 +277,15 @@ void wxToolTip::SetMaxWidth(int width)
     ms_maxWidth = width;
 }
 
+void wxToolTip::DeleteToolTipCtrl()
+{
+    if ( ms_hwndTT )
+    {
+        ::DestroyWindow((HWND)ms_hwndTT);
+        ms_hwndTT = (WXHWND)NULL;
+    }
+}
+
 // ---------------------------------------------------------------------------
 // implementation helpers
 // ---------------------------------------------------------------------------