To Reproduce:

1. Open the attached project.

2. Click on kaboom.txt in /Assets/Sounds, notice that Asset Bundle (in the inspector) is set to None.

3. Click BugReport/SetBundleName=myBundle & click print bundle content.

4. Click Edit/Undo 'Change AssetBundle name'.

5. Click on 'kaboom.txt', notice that Asset Bundle is set back to None.

6. Notice that 'BugReport/Print Asset Bundle Content' still prints out that content, because even if the bundle names was changed back GetAssetPathsFromAssetBundle, still returns it's contents.

7. GetAssetPathsFromAssetBundle works as expected if AssetDatabase.RemoveUnusedAssetBundleNames() is called instead of using Undo.RecordObject to change back the importers state.