Since I've upgraded to php 4.3.1 I'm getting the following error with my scripts using ob_gzhandler:

Warning: (null)() [ref.outcontrol]: output handler 'ob_gzhandler' cannot be used twice in Unknown on line 0

The wierd thing is that I was getting the warning just when opening the page for the first time, while subsequent ones where ok. 

I've lurked across the archive. There's the claim that that problem had been fixed but imho it has not been fixed completely (see below). As a workaround I've found that I've to check if some other handler is loaded before trying to compress. I did it and I'm no longer getting that error.

By the way I don't know who is starting that handler!


In my configuration I've set:

  output_buffering        = Off
  output_handler          =
  zlib.output_compression = Off

The following script reproduces the problem:

<?
    session_start();

    $_SESSION['N'] =  (isset($_SESSION['N']) ? ++$_SESSION['N'] : 1);

    echo "Level = " . ob_get_level() . ";<br>";
    echo "Iteration = " . $_SESSION['N'] . ";<br>";
?>

The first time it's launched I get "Level = 1".
From the second iteration on, I get "Level = 0".


It looks like that starting a session makes an ob handler start.

Is this behaviour correct?

I'm using RedHat Linux 6.2 with kernel 2.2.18, glibc-2.1.3-28, gcc-2.96-98, apache 1.3.27 and php 4.3.1.
This is my "configure" line:

./configure \
    --with-apxs=/usr/sbin/apxs \
    --with-config-file-path=/etc/httpd/conf \
    --with-java=/usr/java/jdk1.3.1_02 \
    --disable-cgi \
    --with-tsrm-pthreads \
    --enable-trans-sid \
    --enable-sysvsem \
    --enable-sysvshm \
    --with-zlib \
    --with-ssl=shared \
    --with-dom=shared \
    --enable-xslt=shared \
      --with-xslt-sablot \
    --with-curl=shared \
    --with-gd \
      --with-jpeg-dir \
      --enable-gd-native-ttf \
      --enable-gd-imgstrttf \
    --with-mysql=shared \
    --with-recode=shared \
    --enable-calendar \
    --enable-dba=shared \
      --with-gdbm \
      --with-ndbm \
      --with-cdb \
      --with-db2 \
      --with-flatfile\
    --with-kerberos