Wt

After calling "setZoom" on "WcartesianChart" twice, the chart's "setZoom" will not work anymore.

Code on setZoom(1.5) button:

 auto b = new WPushButton("setZoom(1.5) ",this);
  b->clicked().connect([chart](const Wt::WMouseEvent&) {

    chart->axis(YAxis).setZoom(1.5);
    chart->axis(XAxis).setZoom(1.5);
  });

Please use the attached project to reproduce the problem.

Step to reproduce

1. Build and Run the attached project
   
2. Open the browser
   
3. Click the "setZoom(1.5)" button twice*
   
4. Zoom out the chart by ctrl+scroll
   
5. click the "setZoom(1.5)" button again.

Result

"setZoom(1.5)" button is no longer work.

Environment

GCC G 5.2.1 Wt 3.3.5

*The setZoom works correctly, If the button was click only once and then going to step 4.