Greetings,

Attached is a trivial fix, and a test case.

Thanks,

2018-04-09  Paul Pluzhnikov  <ppluzhnikov@google.com>

         [BZ #22786]
         * stdlib/canonicalize.c (__realpath): Fix overflow in path length
         computation.
         * stdlib/Makefile (test-bz22786): New test.
         * stdlib/test-bz22786.c: New test.

-- 
Paul Pluzhnikov