https://bugs.winehq.org/show_bug.cgi?id=35127
--- Comment #18 from Zhiyi Zhang yi.gd.cn@gmail.com --- Further experiment on Windows by calling related api and dumping the memory pointed by HTREEITEM, $HTREEITEM+0x1a is the textWidth member. And since the content 2 bytes before and after $HTREEITEM+0x1a is not zero, and don't change with the text of the item. It's reasonable to believe that textWidth is not a LONG but a WORD.