Hi Torben,
I am sorry for the unclear explanation. Based from your example foobar1, foobar2, foobar2, foodir, subfoo and foobar5 will all get the context id of foo.com. Which is the way the current system works. But any site nodes under subfoo will get the context id of subfoo if you are at foo.com/foodir/subfoo/admin/site-map (current behaviour). But if you are at foo.com/admin/site-map any nodes under subfoo will get the context id of foo.com. (I believe this is what Barry has pointed, I haven't tried it personally). My suggestion is that both pages at foo.com/foodir/subfoo/admin/site-map or foo.com/admin/site-map will behave the same way, where in all nodes under subfoo will get its context id.
To rephrase my suggestion. Site nodes will inherit the context id of the nearest parent subsite, irregardless of where the UI is being used. This behaviour is very similar to the current one. We must then futher discuss if we are indeed to make the change of inheriting from the parent side node.
