compatibility with wxWdigets 2.9+: Handle MOUSE_CAPTURE_LOST event

src/gui/about_window.cpp

@@ -100,6 +100,10 @@ void HoverButtonBase::onLeftUp(wxMouseEvent&) {
 		onClick();
 	}
 }
+void HoverButtonBase::onLoseCapture(wxMouseCaptureLostEvent&) {
+	// We already test for wrong release with HasCapture()
+	// but stupid wxWidget people decided to throw assertion failures
+}
 void HoverButtonBase::onKeyDown(wxKeyEvent& ev) {
 	int code = ev.GetKeyCode();
 	if (code == WXK_RETURN || code == WXK_SPACE) {
@@ -147,6 +151,7 @@ BEGIN_EVENT_TABLE(HoverButtonBase, wxControl)
 	EVT_LEFT_UP        (HoverButtonBase::onLeftUp)
 	EVT_KEY_DOWN       (HoverButtonBase::onKeyDown)
 	EVT_KEY_UP         (HoverButtonBase::onKeyUp)
+	EVT_MOUSE_CAPTURE_LOST(HoverButtonBase::onLoseCapture)
 END_EVENT_TABLE  ()
 
 // ----------------------------------------------------------------------------- : Button with image and hover effect

src/gui/about_window.hpp

@@ -50,6 +50,7 @@ class HoverButtonBase : public wxControl {
 	void onKillFocus (wxFocusEvent& ev);
 	void onLeftUp    (wxMouseEvent&);
 	void onLeftDown  (wxMouseEvent&);
+	void onLoseCapture(wxMouseCaptureLostEvent&);
 	void onKeyDown   (wxKeyEvent&);
 	void onKeyUp     (wxKeyEvent&);
 	void onPaint     (wxPaintEvent&);