Description:
------------
When I using Phing, My testcase with PEAR-SOAP and rdfapi-php had stopped with segmentation fault.

And I Found that throwing exception in error_handler causes Seg fault.



Reproduce code:
---------------
<?php
set_error_handler('errorHandler', E_USER_ERROR);
try{
    test();
}catch(Exception $e){
}
restore_error_handler();

function test(){
    trigger_error("error", E_USER_ERROR);
}

function errorHandler($errno, $errstr, $errfile, $errline) {
    throw new Exception();
}
?>
-----
no try and catch
<?php
set_error_handler('errorHandler', E_USER_ERROR);
test();
restore_error_handler();

function test(){
    trigger_error("error", E_USER_ERROR);
}

function errorHandler($errno, $errstr, $errfile, $errline) {
    throw new Exception();
}
?>


Expected result:
----------------
nothing

Actual result:
--------------
*** glibc detected *** double free or corruption: 0x0000000000af7970 ***
*** glibc detected *** double free or corruption: 0x0000000000af7a10 ***
*** glibc detected *** double free or corruption: 0x0000000000af07b0 ***
------
no try and catch

Fatal error: Uncaught exception 'Exception' in /usr/home/kent/tests/trigger_errorTest.php:11
Stack trace:
#0 [internal function]: errorHandler(256, 'error', '/usr/home/kent/...', 7, Array)
#1 /usr/home/kent/tests/trigger_errorTest.php(7): trigger_error('error', 256)
#2 /usr/home/kent/tests/trigger_errorTest.php(3): test()
#3 {main}
  thrown in /usr/home/kent/tests/trigger_errorTest.php on line 11
*** glibc detected *** double free or corruption: 0x0000000000af7870 ***
*** glibc detected *** double free or corruption: 0x0000000000af7910 ***
Segmentation fault