Entity predicates for advancements fail if "type" not specified

The bug

The following advancement will not be granted due to the lack of a type string:

{
    "criteria": {
        "run": {
            "trigger": "minecraft:player_hurt_entity",
            "conditions": {
                "damage": {
                    "source_entity": {
                        "nbt": "{SelectedItem:{}}"
                    }
                }
            }
        }
    }
}

Adding type will allow all checks to function correctly:

{
    "criteria": {
        "run": {
            "trigger": "minecraft:player_hurt_entity",
            "conditions": {
                "damage": {
                    "source_entity": {
                        "type": "minecraft:player",
                        "nbt": "{SelectedItem:{}}"
                    }
                }
            }
        }
    }
}

Code analysis

In 1.12 MCP, net.minecraft.advancements.critereon.EntityPredicate(), the method to compare the incoming entity to the data contains this line, which first ensures that type was specified before comparing it to the incoming entity:

else if (this.field_192484_b != null && !EntityList.isStringEntityName(p_192482_2_, this.field_192484_b))
{
    return false;
}

However, in 1.13, the check for null does not exist, meaning the whole predicate fails at this point (preventing all other options from working).