Reproducing Steps:

1. open zss.test/display.zul
2. select the sheet ""chart-image""
3. enlarge column C's width by dragging it (If you enlarge any column right to column C will cause this error.)

Actual:
2 JavaScript errors show.

TypeError: img is undefined
http://localhost:8080/zss.test/zkau/web/80cecf46/js/zk.wpd
Line 24403
img.useMap = bArea ? '#' + mapid : '';

TypeError: img is null
http://localhost:8080/zss.test/zkau/web/80cecf46/js/zk.wpd
Line 24403
img.useMap = bArea ? '#' + mapid : '';"