Steps to reproduce:
1. Open the attached project (842635-TestCase.zip)
2. Open the Assets/test.unity scene
3. Open Scene View
4. Click on one of the buttons in the Editor Scene View
5. Button is selected instead of the game object with Test.cs script

Expected result: TestObject should be selected
Actual result: Button is selected instead of the game object(TestObject) with Test.cs script

Reproduced with: 5.3.6p8, 5.4.1f1, 5.4.3p3, 5.5.0p1, 5.6.0a6