Steps to reproduce:
1. Open my attached project "case_816355Test".
2. Enter play mode.
3. Exit play mode.
---In the console window "NullReferenceException" message appears.

Expected results: Script "SomeStaticClass" should create new game object, rename it and Undo.RevertAllInCurrentGroup() should revert him to original state (in this case reverting his name).

Actual results: Script "SomeStaticClass" doesn't even create new object so there is not even a chance to rename it and use Undo function to revert changes. Deleting
Undo.RevertAllInCurrentGroup() function in "SomeStaticClass" at least creates new object and renames it.

--- Side note: "UndoExample" script, which can be found in project menu, implements almost the same behavior as "SomeStaticClass" but not in "OnSceneGUI" method. This lets Undo.RevertAllInCurrentGroup() reverse the state of the object (in this script it just changes his name to the original).

Reproduced with: 5.5.0a6, 5.4.0p2, 5.3.5f1, 5.2.0f3