Category click handler accesses an item before checking for None

[CYooBin10]

Labels: high, bug, crash, menu

Description

The category click handler reads the item's metadata before verifying that the item exists.

The current order is effectively:

name = items.item_meta.display_name

followed by:

if items is None

Steps to reproduce

Click a slot for which inv.get_item(slot) returns None.

Actual behavior

The handler can throw an exception while accessing item_meta.

Expected behavior

Check that the item and its metadata exist before accessing any properties.