Hi Yang,

> ---
>  src/stkutil.c       |   22 ++++++++++++++++++++++
>  src/stkutil.h       |   28 ++++++++++++++++++----------
>  unit/test-stkutil.c |    2 +-
>  3 files changed, 41 insertions(+), 11 deletions(-)

I think the patch is fine, but no longer applies.  Please rebase and resubmit 
this one.

Regards,
-Denis