sock_for_fd.h in kgio-1.2.0

- old
+ new

@@ -1,5 +1,7 @@
+#ifndef SOCK_FOR_FD_H
+#define SOCK_FOR_FD_H
 #include <ruby.h>
 #ifdef HAVE_RUBY_IO_H
 #  include <ruby/io.h>
 #else
 #  include <stdio.h>
@@ -62,5 +64,6 @@
 }
 #endif /* sock_for_fd */
 #if SOCK_FOR_FD > 0
 #  define init_sock_for_fd() if (0)
 #endif
+#endif /* SOCK_FOR_FD_H */