Merge process causes duplicate entries in parent transitions.

As a result, after merging in flow3:list:show will be 6 actions (which is correct), but in flow1:list:show will be the 6 objects too (which is wrong).

Wrong behavior takes place, because actions shares the same LinkedList.

In your source code:
public void merge(Model model)

{ TransitionModel transition = (TransitionModel) model; setOnException(merge(getOnException(), transition.getOnException())); setTo(merge(getTo(), transition.getTo())); setBind(merge(getBind(), transition.getBind())); setBind(merge(getValidate(), transition.getValidate())); <---- besides, are you sure this string is correct? setHistory(merge(getHistory(), transition.getHistory())); setAttributes(merge(getAttributes(), transition.getAttributes())); setSecured((SecuredModel) merge(getSecured(), transition.getSecured())); setActions(merge(getActions(), transition.getActions(), false)); <------------- wrong. }

Proposed change:
LinkedList mergeResult = merge(getActions(), transition.getActions(), false);
setActions(mergeResult != null ? new LinkedList(mergeResult) : null);