How to reproduce:
1. Create a new project
2. Open the Inspector window
3. Create an empty GameObject in the Hierarchy
4. Delete the name of the GameObject in the Inspector and click enter

Expected result: The name of the GameObject is left unchanged
Actual result: The name of the GameObject is set to an empty string

Reproducible with: 2017.4.30f1, 2018.4.4f1, 2019.1.10f1, 2019.2.0b9, 2019.3.0a9

Notes:
Deleting the name by changing it in the Hierarchy will behave as expected.
Trying to create a Prefab from a GameObject with no name will result in Console error.
Since Unity version 2018.3.0a6 trying to create a Prefab from a GameObject with no name will additionally result in "Access is denied" error message.
Since Unity version 2018.3.0a6 trying to create a Prefab from a GameObject with no name will make a Prefab with a broken Prefab Connection.