https://bugs.winehq.org/show_bug.cgi?id=50885
--- Comment #4 from Lauri Kenttä lauri.kentta@gmail.com --- Comparing traces of -0.0 and +0.0 it looks like a bug in ecvt_s which fails to recognize negative zero and assumes that only numbers <0 are negative. Same for all similar cvt functions. I'll send a patch.