setsockopt on mingw

[Simon Josefsson]

Hi.

Under MinGW, setsockopt has a 'const char*' 4th argument instead of
'const void*' as specified by POSIX, compare:

http://www.opengroup.org/onlinepubs/009695399/functions/setsockopt.html

with

http://msdn2.microsoft.com/en-us/library/ms740476.aspx

This was raised in this report against gnutls:

http://thread.gmane.org/gmane.network.gnutls.general/1145/focus=1195

The follow patch appear to silent compiler warnings.  Can anyone think
of a better way to fix this?  If not I'll commit and push this shortly.

/Simon

2008-04-22  Simon Josefsson  <address@hidden>

        * lib/sys_socket.in.h: Define setsockopt macro to cast fourth
        parameter to void* as per POSIX standard (MinGW uses char*).

diff --git a/lib/sys_socket.in.h b/lib/sys_socket.in.h
index d94f425..cb84220 100644
--- a/lib/sys_socket.in.h
+++ b/lib/sys_socket.in.h
@@ -102,6 +102,10 @@
 #  define ESHUTDOWN               WSAESHUTDOWN
 # endif
 
+# if defined _WIN32 || defined __WIN32__
+#  define setsockopt(a,b,c,d,e) setsockopt(a,b,c,(const void*)(d),e)
+# endif
+
 #endif /* HAVE_SYS_SOCKET_H */
 
 #endif /* _GL_SYS_SOCKET_H */