Don't set the event type until we are sure it is a vertical wheel event. (Horizontal wheel events are not

supported in 2.8 and can cause a divide-by-zero if they are handled incorrectly.)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@48313 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/mac/carbon/toplevel.cpp

@@ -364,13 +364,12 @@ void SetupMouseEvent( wxMouseEvent &wxevent , wxMacCarbonEvent &cEvent )
 
          case kEventMouseWheelMoved :
             {
-                wxevent.SetEventType( wxEVT_MOUSEWHEEL ) ;
-
                 EventMouseWheelAxis axis = cEvent.GetParameter<EventMouseWheelAxis>(kEventParamMouseWheelAxis, typeMouseWheelAxis) ;
                 SInt32 delta = cEvent.GetParameter<SInt32>(kEventParamMouseWheelDelta, typeSInt32) ;
 
                 if ( axis == kEventMouseWheelAxisY )
                 {
+                    wxevent.SetEventType( wxEVT_MOUSEWHEEL ) ;
                     wxevent.m_wheelRotation = delta;
                     wxevent.m_wheelDelta = 1;
                     wxevent.m_linesPerAction = 1;