https://bugs.winehq.org/show_bug.cgi?id=35127
--- Comment #23 from Zhiyi Zhang yi.gd.cn@gmail.com --- Tests show that there are times the content 2 bytes before and after $HTREEITEM+0x1a is not zero(Once there are 0x1 at lower 2 bytes). You can dump the memory of HTREEITEM pointed to to check it. And since MSDN says the pszText max displayed text will be 260 characters, I am pretty sure textWidth is a WORD.