Redmine

1. create a parent project with a child
2. create a version for the child project, choosing "With project hierarchy" for the Sharing option
3. create a issue for the parent and assign it to the child's version
4. go to the parent's roadmap
5. The child's version should show up on the parent's roadmap. There should be a "1 open" link. Click on it.

BUG:
You are taken to an empty issue list. This seems to be happening because the link takes you to the child project where parent issues can not be seen.

1. allow parent issues assigned to child versions to be viewed in the child's issue list (my preference)
2. Change the link from the parent roadmap so it jumps to the parent's issue list instead of the childs. With this solution there would still be the awkwardness that the child's roadmap (which shows parent issues assigned to it's version) would exhibit this strange behavior. You can see this be complete the same reproduction steps above but this time use the "1 open" link on the child's roadmap page instead of the parents.