Importing strchrnul() from gnulib?

[Wolfram Sang]

Hi,

taking another approach at Bug 19070, I noticed that
dlls/hhctrl.ocx/hhctrl.c has even more problems with commandline-handling.
All three invocations of strchr() should better be strchrnul(). (Compare
calling hh.exe with '-mapid' and '-mapid ' to see one difference).
strchrnul ist protected by _GNU_SOURCE, though. Because I could imagine
there are more places throughout the source needing a fix like this, I
think about importing strchrnul() directly from gnulib into
libs/wine/string.c (most appropriate place I could find). The function is
LGPLv2+, of course. Objections?

Regards,

   Wolfram