Description:
------------
Calling Memcached with invalid keys (too long, invalid characters) leads to 
strange behavior.
Calling get with an invalid key and after that getMulti with a valid key does not 
work (see below).


Versions:
memcached support => enabled
libmemcached version => 0.52

PECL:
memcached 1.0.2   stable


Test script:
---------------
<?php

class MemcachedTest extends \PHPUnit_Framework_TestCase
{
    public function testSet()
    {
        $mc = new Memcached();
        $mc->addServer('127.0.0.1', 11211);

        $mc->get(str_pad('', 300, 'x'));
        // it is "NOT FOUND"
        $this->assertEquals(Memcached::RES_BAD_KEY_PROVIDED, $mc->getResultCode());

        $mc->getMulti(array('foo'));
        // it is "SERVER HAS FAILED AND IS DISABLED UNTIL TIMED RETRY"
        $this->assertEquals(Memcached::RES_BAD_KEY_PROVIDED, $mc->getResultCode());
    }
}


Expected result:
----------------
The first $mc->get should lead to a result code "BAD KEY PROVIDED".
The second $mc->getMulti be "NOT FOUND" or "SUCCESS" depending on the cache 
content.

Actual result:
--------------
The first $mc->get sets the result code to "NOT FOUND".
The second $mc->getMulti sets the result code to "SERVER HAS FAILED AND IS 
DISABLED UNTIL TIMED RETRY".