file cancel link missing in fileupload dialog

Steps to Reproduce

reproducing code

<zk>
	<zscript><![CDATA[
		public void upload() {
			Fileupload.get(new EventListener() {
				public void onEvent(Event e) {
					Clients.log(e.getMedia().getName());
				}
			});
		}
	]]></zscript>
	<button label="trigger upload dialog" onClick="upload();"/>
</zk>

click the button to display the fileupload dialog
add one file
wait for the upload to finish

Current Result

in 8.5.2.1 the file shows upload progress and when finished remains visible with a "cancel" link

in 8.6.0.1 the file shows upload progress and when finished disappears leaving an empty dialog

Expected Result

same or similar as in 8.5.2.1

Debug Info

this div becomes visible in 8.5 but remains invisible since 8.6

Root Cause

since 8.6.0 the finish function is no longer called to display the successfully uploaded file information

Instead the cancel function is always called when a file was uploaded successfully or an error occurred

Workaround

manually keep track of the error state and call the expected function accordingly later

zk.afterLoad('zul', function() {
	var xUpload = {};
	zk.override(zul.Upload, xUpload, {
		error : function(msg, uuid, sid) {
			var wgt = zk.Widget.$(uuid);
			if(wgt) {
				wgt._hasUploadError = true;
			}
			return xUpload.error.apply(this, arguments);
		},
		close : function(uuid, sid) {
			var wgt = zk.Widget.$(uuid);
			if (!wgt || !wgt._uplder) return;
			if(wgt._hasUploadError) {
				wgt._uplder.cancel(sid);
			} else {
				wgt._uplder.finish(sid);
			}
		}
	});//zk.override
});//zk.afterLoad

(this is not the suggested fix, but requires little overriding to patch)