+#if defined (_WIN32) && !defined (__CYGWIN__)
+
+/* 'isatty' in the Windows runtime returns non-zero for every
+ character device, including the null device. Repair that. */
+#include <io.h>
+#define WIN32_LEAN_AND_MEAN 1
+#include <windows.h>
+
+int w32_isatty (int fd)
+{
+ if (_isatty(fd))
+ {
+ HANDLE h = (HANDLE) _get_osfhandle (fd);
+ DWORD ignored;
+
+ if (h == INVALID_HANDLE_VALUE)
+ {
+ errno = EBADF;
+ return 0;
+ }
+ if (GetConsoleMode (h, &ignored) != 0)
+ return 1;
+ }
+ errno = ENOTTY;
+ return 0;
+}
+
+#define isatty(x) w32_isatty(x)
+#endif
+