Your test doesn't make much sense. The call to FindClose should be done after you check the result of GetLastError, since FindClose <should> change the last error to ERROR_SUCCESS if the close operation was successful.
From your test results, it seems that the FindClose implementation on theversion of windows you're using doesn't seem to do this. I would consider this a bug in windows, not a bug in Wine. If a programmer relies on this behavior, it's their fault, not MS's or Wine's fault that their code does not work
AFAIK, it's never said that a successful function call should set the last error to 0. This only thing MS claims is that when a function fails, the last error is set to a error code explaining that error.
Moreover, wine's goal is not to make a better design than windows, but to mimic windows behavior. So, if FindClose doesn't change the last error on success, wine should do the same (especially if some known program depends on it)
A+ -- Eric Pouech
