Reproduction steps:
1. Open the "Terrain Generator" project
2. Open "_Demo\Demo.unity" scene
3. Play the scene
4. Drag right most gameobject to the left with the right mouse button to the middle gameobject.
5. Notice in the console that new ID is not ignored and does not match UIUtility.hotControl.

NOTE: Dragging middle gameobject to the right new higher ID is ignored.

Actual result: New id is not ignored even thou new ID and UIUtility.hotControl does not match.
Expected result: New ID gets ignored because it doesn't match with UIUtility.hotControl.

Reproduced on: 5.4.0f3, 5.3.5f1
Scripts are not working in 5.2.*