Sort order is not obeyed if a child item has the same name as its parent

[chrisjrn]

Steps to reproduce:

1. Create an item called "B"
2. Add a child of "B" called "A"
3. Add a child of "B" called "B"
4. (Note that the children of "B" are "A" and "B" in that order)
5. Press the "Up" sort button next to the child "B"

Expected: "B" appears above "A" as a child of "B".
Actual: "B" remains below "A"

Further: If Parent "B" is renamed to "C", the sort order change from above is reflected correctly.

[idlesign]

And what cache backend is used?

[idlesign]

Considered closed.
Feel free to reopen if required.