<ulm> mgorny: there was an "inheritmembers" attribute <ulm> for example proj/en/lisp/index.xml would have: <ulm> <subproject ref="/proj/en/lisp/emacs/index.xml" inheritmembers="yes" /> We seem to be lacking such a possibility in the wiki.
AFAICS, this would have to be a flag in the subproject page, i.e. the ParentProject element would need some bit that indicates that the subproject members are propagated to the parent project.
Not sure why this bug is restricted. Lifting that. Also not sure why commentary surrounding your quote hints at your requests not being considered seriously. This is a reasonable feature after all. Projects can now indicate that they propagate members to their parents. Parents list them in the subprojects section which is now directly beneath the parents' members list. That is the case as querying multiple lists of members and uniq'ing them isn't easily doable with the expressiveness of the built-in query language. When exporting data, this can be of course handled differently.
