#24346 [Bgs]: ob_start wrongly optimized out when no callback specified
ID: 24346
User updated by: pitrou at free dot fr
Reported By: pitrou at free dot fr
Status: Bogus
Bug Type: Output Control
Operating System: Linux
PHP Version: 4.3.2
New Comment:
Ok, then there's a compatibility problem (it used to work before).
Also the documentation is bogus too:
http://www.php.net/manual/en/function.ob-start.php
It doesn't mention the return value, the return type is
even supposed to be "void". How can I know I'm supposed to
check the return value ?
In the end I think a bad callback parameter to ob_start is enough to
print an error message on screen (just as calling a function which
doesn't exist prints an error message on screen).
Thanks for the reply.
Previous Comments:
------------------------------------------------------------------------
[2003-06-26 09:38:18] derick@php.net
You should use NO parameter if you don't want a handler. PHP 4.3.2
correctly returns FALSE in this case.
------------------------------------------------------------------------
[2003-06-26 09:33:35] pitrou at free dot fr
Description:
------------
Newly with PHP 4.3.2, calls to ob_start with an empty handler (i.e.
ob_start("")) seem to be optimized out and ignored.
This causes two problems :
- ob_start("") can be useful if you prefer to process the
contents manually by using ob_get_contents() and then
ob_end_clean()
- nesting of output buffers is broken, because the ob_end()
call corresponding to ob_start("") is still taken (which
can totally break the page if your ob_start("") is nested
inside an ob_start("ob_gzhandler")...)
Reproduce code:
---------------
** This one doesn't work (second statement is eaten out) :
<?php
ob_start("ob_gzhandler");
ob_start("");
echo "first echo<p>";
ob_end_flush();
echo "second echo<p>";
ob_end_flush();
?>
** This one works (both statements are printed) :
<?php
function foo($x) { return $x; }
ob_start("ob_gzhandler");
ob_start("foo");
echo "first echo<p>";
ob_end_flush();
echo "second echo<p>";
ob_end_flush();
?>
Expected result:
----------------
Both programs should have the same result (i.e. print both statements
on screen).
Actual result:
--------------
The program which calls ob_start with an empty handler fails to display
the second statement. In the other program, we circumvent this bug by
using a dummy handler, which causes it to work properly.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=24346&edit=1
Thread (3 messages)