Fix move (rename, copy) node damage urls

__Tasks:__

- [x] test coverage
- [ ] gather feedback for my changes
- [x] submit changes to the documentation

Fixes: #616

__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | yes
| Fixed tickets | #616
| BC Breaks     | none
| Doc           | none
Can you rewrite that a bit? These two ifs could be combined to one, and you could check if `$old` is null and the beginning, and return earlier. Would already save 2 nestings.