Description:
------------
The C function "php_end_ob_buffer" from "main/output.c" destroys output_handler on first call so the second call to output_handler is not possible. "php_end_ob_buffer" is called by "ob_flush()" and "ob_clean()" those must not destroy output handler.

Look into line 250:

zval_ptr_dtor(&OG(active_ob_buffer).output_handler);

The same error is in PHP-4.3.3RC2 too.

Reproduce code:
---------------
<?php

function test($s,$mode) {
  return (($mode & PHP_OUTPUT_HANDLER_START)?"[":"").
         $s.
         (($mode & PHP_OUTPUT_HANDLER_END)?"]\n":"");
}

function t1() {
  ob_start("test");
  echo "Hello from t1 1 ";
  echo "Hello from t1 2 ";
  ob_end_flush();
}

function t2() {
  ob_start("test");
  echo "Hello from t2 1 ";
  ob_flush();
  echo "Hello from t2 2 ";
  ob_end_flush();
}


function t3() {
  ob_start("test");
  echo "Hello from t3 1 ";
  ob_clean();
  echo "Hello from t3 2 ";
  ob_end_flush();
}

t1(); echo "\n";
t2(); echo "\n"; 
t3(); echo "\n";
?>

Expected result:
----------------
[Hello from t1 1 Hello from t1 2 ]

[Hello from t2 1 Hello from t2 2]

[Hello from t3 2]

Actual result:
--------------
[Hello from t1 1 Hello from t1 2 ]

[Hello from t2 1 Hello from t2 2
Hello from t3 2