Description:
------------
5.4.3 64 bit

increment / decrement operations failing with binary protocol in the following 
scenario.

add operation returns incorrect result (true instead of false)

there is no bug without binary protocol

Test script:
---------------
!/bin/env spartan-test

// spartan-test unit test: https://github.com/parf/spartan-test
// PHP memcached extension BUG

$mc = new Memcached();
#={"class":"Memcached","0":{}}
- $mc->addServer("localhost", 11211);

# this options are irrelevant
#- $mc->setOption(Memcached::OPT_SERIALIZER, Memcached::SERIALIZER_IGBINARY);
#- $mc->setOption(Memcached::OPT_LIBKETAMA_COMPATIBLE, true);
#- $mc->setOption(Memcached::OPT_TCP_NODELAY,true);

# this IS a bug option - binary protocol messes things up
- $mc->setOption(Memcached::OPT_BINARY_PROTOCOL, true);

$mc->getVersion();
#={"localhost:11211":"1.4.10"}

# #={"p:11211":"1.4.10"}  << test on another server also have same issue

phpversion();
#="5.4.3"

# 5.4.1 was also tested

# no idea hwo to get pecl package version from php.
# rpm -qa | grep php-pecl-memcached : php-pecl-memcached-2.0.1-6.el6.remi.x86_64

- $key="key-for-testing";

# OK CASE·
$mc->set($key, 0);
#=true
$mc->increment($key);
#=1
$mc->increment($key);
#=2
$mc->increment($key);
#=3

# BUG CASE
# extra get after set messes subsequent increments
$mc->set($key, 0);
#=true
$mc->get($key);
#=0
# OMG - BUG !!!·
$mc->increment($key);
#=-1
$mc->increment($key);
#=1
$mc->increment($key);
#=2




# ANOTHER BUG
- $mc->delete($key);

## add if not exists
$mc->add($key, "abc");
#=true
$mc->get($key);
#="abc"

## BUG in memcached extension
## - it returned true, and it should return false !!!
$mc->add($key, "def");
#=true
$mc->get($key);
#="abc"


Expected result:
----------------
$mc = new Memcached();
#={"class":"Memcached","0":{}}
- $mc->addServer("localhost", 11211);
- $mc->setOption(Memcached::OPT_BINARY_PROTOCOL, true);


# extra get after set messes subsequent increments
$mc->set($key, 0);
#=true
$mc->get($key);
#=0
$mc->increment($key);
#=1
$mc->increment($key);
#=2
$mc->increment($key);
#=3