context isn't passed to enclosing page during form submit

I'm not sure if this is a bug or not.

Here's a scenario:

Page.java

public class Page {
@Property
private Entity entity;

void onActivate ( Long id ) {
entity = retrieveFromDatabase ( id );

Page.tml:

<t:mycomponent entity="entity"/>

MyComponent.tml:

<t:form p:context="entity.id">
...
</t:form>

AJAX is NOT used. If I get it right, form context must be passed to
enclosing page during form submission. However it doesn't work and
appropriate onActivate method is never called, although submission URL
looks just like expected:
http://localhost:8080/application/page.mycomponent.form/12345

Am I missing something here? I'm using 5.4-beta6