WC3: `BlzSetItemBooleanFieldBJ` overwrites other fields


In the world editor, the JASS function BlzSetItemBooleanFieldBJ does not work correctly.
It appears to modify other boolean fields of the item.
I expect that the different fields are stored in the same machine word, and that BlzSetItemBooleanFieldBJ overwrites the complete machine word rather than modifying only the one bit responsible for the behavior.