commit 8f2f08d04f969f27dad47ee2d9dcbe567f2873bc
Author: Roland McGrath <roland@hack.frob.com>
Date:   Thu May 1 13:33:13 2014 -0700

    Fix -Wundef warnings for _IO_JUMPS_OFFSET.

diff --git a/libio/libioP.h b/libio/libioP.h
index c170b872028c7a5f..b60244ac5fc3d908 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -100,6 +100,8 @@ extern "C" {
 #if (!defined _IO_USE_OLD_IO_FILE \
      && (!defined _G_IO_NO_BACKWARD_COMPAT || _G_IO_NO_BACKWARD_COMPAT == 0))
 # define _IO_JUMPS_OFFSET 1
+#else
+# define _IO_JUMPS_OFFSET 0
 #endif
 
 #define _IO_JUMPS(THIS) (THIS)->vtable