Facelets Compatibility: ui:insert nested in ui:include not added to component tree

When having a structure where a ui:insert is used in a file included by ui:include, the components that should be added by the ui:insert are not added to the component tree or at least not before other components are processed.

So the structure is as follows:
ui:composition (test.xhtml) uses template (template.xhtml) and defines a header that is included from another file using ui:include (test_header.xhtml)
template (template.xhtml) includes a ui:composition (header.xhtml) that inserts the header into the template

The composite component specified in test_header.xhtml is not added to the component tree before the update attribute of a commandButton is processed and throws a ComponentNotFoundException.

You probably didn't understand a single thing, so the easiest is to take a look at the primefaces-test project I created here: https://github.com/mkomko/primefaces-test/tree/component-not-found

I can't say for sure if this structure is supported by the spec, but it works in Mojarra.

It works using 

mvn clean jetty:run -Pmojarra40

 but not using 

mvn clean jetty:run -Pmyfaces40

Thank you very much in advance for taking a look! We're evaluating migrating our large web application from Mojarra to MyFaces, so you might hear from me again .