The task hierarchy is not consistently shown
In my redmine project (on hostedredmine.com), my hierarchy is not correctly displayed in the 'issues' view.
I reproduced this on demo.redmine.org.
See http://demo.redmine.org/projects/invalid-date-bug/issues .
There is a task with 4 subtasks.
If you add a task (not a child task), the 'issues' view will no longer show a hierarchy.
If you delete the task, the hierarchy will re-appear.
It seems like the hierarchy implementation is a bit smelly, which is possibly related to the fact that I was also suffering from the supposedly fixed issue #6378 , but cannot easily reproduce it on demo.redmine.org.
Please DO NOT do anything more than adding/deleting your own, single task (unless you're a developer that knows what he's doing) -- otherwise you may destroy this bug reproduction.