When renaming an item on the anvil and deleting all characters of its name, the anvil output is not updated.
This is primarily a nuisance when deleting all characters in a renamed item's name to revert to the default item name.

How to reproduce:

1. Put an item onto the anvil and remove all but a single character in its name: The item name is updated in the output slot.

1. Remove the last character left in its name: The output slot is not updated.

1. Insert any character, even space, to update the output slot.

You can also get the issue when you remove multiple selected characters at once:

1. Put an item onto the anvil and delete some characters from its name: The item name is updated in the output slot.

1. Select all characters left in its name and press backspace: The output slot is not updated.

1. Insert any character, even space, to update the output slot.