Description:
------------
In non-blocking mode fgets should buffer data it read from stream until it meets eol or eof instead of returning anything it read. 

Test script:
---------------
$ cat test1.php 
<?php
fwrite(STDOUT, 'test1');
sleep(5);
fwrite(STDOUT, "\n");
sleep(5);
fwrite(STDOUT, "test2\n");
$ cat test2.php 
<?php
stream_set_blocking(STDIN, false);
do {
    $test = fgets(STDIN);
    if ($test) {
        var_dump($test);
    }
} while (!feof(STDIN));
$ php55 test1.php | php55 test2.php 

Expected result:
----------------
string(6) "test1
"
string(6) "test2
"


Actual result:
--------------
string(5) "test1"
string(1) "
"
string(6) "test2
"