@nsivov do you mean that the name isn't assigned properly to the window when the name start with 0xffff (so it should be assigned but it isn't) or that it should not be assigned at all? I'm sorry, this may be just a language barrier, but it isn't clear that much to me. Where I can look at that? In !693 there is a test that create a window, assign a custom win procedure that copy the name to a buffer, and check the buffer for equality and they match. However the test use DialogBoxParam and I'm not sure where the window with the custom procedure is called (I'm new to this part of the code if we exclude a previous analysis for a regression in win32u). Will be fine in case if the second part is addressed in a separate commit?
Regarding whitespace lines, what are the guidelines? I did see other commits that modify tests, and they do add sometimes whitespace only lines in the code they add. The code I added in the test isn't different from the style used in the !693 tests. As I based the changes to other commits, and there aren't clear giudelines about this in https://wiki.winehq.org/Wine_Developer%27s_Guide/Coding_Practice#Some_notes_... and https://wiki.winehq.org/Submitting_Patches#Code_guidelines I'd like to know if there are informal preferred rules in place.
Thanks for the help.