When trying to exit the Anvil menu window, using the inventory key does not exit the menu. However after clicking anywhere and then trying to exit using the inventory key it exits the menu.
Linked issues
relates to 4
MC-145691
Binding "Open/Close Inventory" to Tab only opens inventory
Resolved
MC-147727
Unable to close anvil using inventory key without taking the input item out, if textfield has focus
Open
MC-147513
Unable to focus anvil textfield by clicking
Resolved
MC-147607
Command block text field isn't focused when opening the GUI anymore
Resolved
Erik Broes
Still not fully fixed in 19w14b.
When the textfield has focus and there is an item to be renamed in the input slot, you still can't close the GUI with the inventory key.
*Edit:
New ticket opened at MC-147727