output buffering bugs

[Anon]

I am using output buffering functions, but it seems that in PHP 4.2.0, 4.2.1 and later they don't work. Not that they do not work at all but a very strange situation occures.
I am trying to catch an output from my script and if this output is less then 4KB (4096) in size everything works perfectly, otherwize nothing does, my scripts' output just falls out.

My code is something like this

one.php

<?
session_start();
echo $something;
?>

two.php

<?
ob_start();
include("one.php");
$contents = ob_get_contents();
ob_end_clean();
echo "This is some text";
echo $contents;
?>

If length of the $something variable in one.php is less then 4096 the the output is ok, otherwithe it is reversed.

[Anon]

Yes, this this exectly the bug I had recently. You see, your output buffering is ok. The problem is in PHP session (in 4.2.0 and later), which uses output buffering too, but not correctly.

The problem is : when you start you output buffering your default buffer size is 40*1024 = 40KB, but if you start session it will change this limit to 4096, and forget about it, i mean that it forgets to close it's output buffering, so if you use session, your output buffer size will always be bound to 4K.
The solution to this problem is to correct the mistake of the session by ourselves, I mean that you should close it's output buffer using ob_end_flush(), after that your limit will be restored, and your script will be working properly.

one.php

<?
session_start();
echo $something;
?>

two.php

<?
ob_start();
include("one.php");
ob_end_flush(); // Correcting session mistake
$contents = ob_get_contents();
ob_end_clean();
echo "This is some text";
echo $contents;
?>