auto_response sets value to garbage if rc=NOT_FOUND

[TimBunce]

auto_response executes *value= instance->root->result.numeric_value; even when rc == NOT_FOUND.

The http://docs.libmemcached.org/memcached_auto.html docs only describe "If the object specified by key does not exist" behaviour for the memcached_*_with_initial variants. However the memcached_*_with_initial variants can't be used with the textual protocol (but that's not mentioned in the docs.)

(This caused a failure in Cache::Memcached::libmemcached https://rt.cpan.org/Ticket/Display.html?id=88376)

[Brian Aker (brianaker)]

  if (memcached_fatal(rc) or memcached_failed(rc))
  {
    assert(memcached_last_error(instance->root) != MEMCACHED_SUCCESS);
    *value= UINT64_MAX;
  }