+#undef getlogin_r
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+ /* Native Windows platform. */
+ DWORD sz;
+
+ /* When size > 0x7fff, the doc says that GetUserName will fail.
+ Actually, on Windows XP SP3, it succeeds. But let's be safe,
+ for the sake of older Windows versions. */
+ if (size > 0x7fff)
+ size = 0x7fff;
+ sz = size;
+ if (!GetUserName (name, &sz))
+ {
+ if (GetLastError () == ERROR_INSUFFICIENT_BUFFER)
+ /* In this case, the doc says that sz contains the required size, but
+ actually, on Windows XP SP3, it contains 2 * the required size. */
+ return ERANGE;
+ else
+ return ENOENT;
+ }
+ return 0;
+#elif HAVE_GETLOGIN_R
+ /* Platform with a getlogin_r() function. */
+ int ret = getlogin_r (name, size);
+
+ if (ret == 0 && memchr (name, '\0', size) == NULL)
+ /* name contains a truncated result. */
+ return ERANGE;
+ return ret;
+#else
+ /* Platform with a getlogin() function. */