Steps to Reproduce

Run attached fullfil.zul

or run fiddle
https://zkfiddle.org/sample/2qci0bo/1-repeating-fullfil-event-listeners

Click "add dynamic item" 3 times

click "clear model" once

click "render all"

Current Result

onFullfill events trigger on the removed components.

each component onFullfil is triggered (1 + number of syncModel called after being added) times 

Expected Result

onFullfill doesn't trigger for removed components

onFullfill is called once per component which hold the listener

Debug Information

org.zkoss.zk.ui.impl.UiEngineImpl.TemplateImpl.create(Component, Component, VariableResolver, Composer) is called on each of the items currently in the model everytime org.zkoss.zuti.zul.ForEachListDataListener.onChange(ListDataEvent) is triggered by adding new elements in the model.

This triggers org.zkoss.zk.ui.impl.UiEngineImpl.execCreate(CreateInfo, NodeInfo, Component, Component) which adds new Fullfill listeners for every existing component, even those who already have a fullfill listener.

Both issues should be solved by clearing fullfill listeners when the content of the shadow templates are destroyed and recreated during modelSync

Workaround