Steps to Reproduce

1. visit the page with IE 10
2. quickly right clicking to open context menu

currently, we cannot reproduce it with local sample.

Actual Result

IE 10 throws a JS exception.

SCRIPT5007: Unable to get property '$instanceof' of undefined or null reference
zk.wpd, line 19703 character 11

Debug Information

Call stack

> _getMenu, zul.menu.wpd, line 1187
open, zul.menu.wpd, line 1323
open, zk.wpd, line 27643
invoke, zk.wpd, line 20207
doProcess, zk.wpd, line 19187
doCmdsNow, zk.wpd, line 19428
_doCmds, zk.wpd, line 19668
afterResponse, zk.wpd, line 19319
onResponseReady, zk.wpd, line 19316

Error Code

p is null.

zul.menu.Menupopup = zk.$extends(zul.wgt.Popup, {
...
( function () {
        function _getMenu(wgt) {
               var p = wgt.parent;
               return p.$instance of(zul.menu.Menu) ? p: null ;
       }
...
}

even we check null in _getMenu(), zk throws another exception in _rmActive() of zul.menu.Menupopup for wgt.parent is null.

...
	_rmActive: function (wgt) {
		if (wgt.parent.$instanceof(zul.menu.Menu)) {
			wgt.parent.$class._rmActive(wgt.parent);
		}
	}

As far, I only know. No matter where the exception happens, Menupopup's parent is always null.

Workaround

I apply the workaround below and the exception never happens.

zul.wgt.Popup.prototype.afterCloseAnima_ = function (opts) {
    this.setVisible(false);
    
    var node = this.$n();
    zk(node).undoVParent();
    zWatch.fireDown('onVParent', this);

    this.setFloating_(false);
    if (opts && opts.sendOnOpen)
        this.fire('onOpen', {open:false});
    if (zk.ie < 11) { 
        this.replaceHTML(node); // remove setTimeout()
    }
    
    //remove extra CSS class
    jq(node).removeClass(this.$s('open'));
};