Description:
------------
I tried to use the Soap 1.2 test files that come with the extension as a starting point, so I copied the soap12-test.wsdl file from ext/soap/tests/soap12 into my DocumentRoot and adapted soap12:address accordingly.
The WSDL file loads just fine, __getFunctions() and __getTypes() seem to work. But when I call any function, the Soap client segfaults without sending any data.

Reproduce code:
---------------
$client = new SoapClient("http://localhost/soap/soap12-test.wsdl", array("soap_version" => 1.2));

var_export($client->__getFunctions()); //ok
var_export($client->__getTypes());     //ok

$x = $client->echoSimpleTypesAsStruct("Alva", 123456, 3.141);

print "OK"; //we never get this far 

Expected result:
----------------
array (
  0 => 'void emptyBody()',
  1 => 'string echoOk(string $echoOk)',
  2 => 'void requiredHeader(string $requiredHeader)',
  3 => 'string echoHeader(string $responseHeader)',

(..)

OK

Actual result:
--------------
#0  0x41093763 in strlen () from /lib/tls/i686/cmov/libc.so.6
#1  0x4011c01a in do_request (this_ptr=0x812711c, request=0x0,
    location=0x81362b4 "http://localhost/soap/soap12-test.php", action=0x0,
    version=512, response=0xbfffcf40)
    at /tmp/php5-200405232030/ext/soap/soap.c:1948
#2  0x4011c546 in do_soap_call (this_ptr=0x812711c,
    function=0x813176c "echoSimpleTypesAsStruct", function_len=23,
    arg_count=3, real_args=0x81311cc, return_value=0x813112c, soap_action=0x0,
    call_uri=0x0, soap_headers=0x0, output_headers=0x0)
    at /tmp/php5-200405232030/ext/soap/soap.c:2022
#3  0x4011d278 in zif_SoapClient___call (ht=0, return_value=0x0, this_ptr=0x0,
    return_value_used=1) at /tmp/php5-200405232030/ext/soap/soap.c:2186
#4  0x402493b2 in zend_call_function (fci=0xbfffd0f0, fci_cache=0x0)
    at /tmp/php5-200405232030/Zend/zend_execute_API.c:853
#5  0x40248ecc in call_user_function_ex (function_table=0x0, object_pp=0x0,
    function_name=0x0, retval_ptr_ptr=0x0, param_count=0, params=0x0,
    no_separation=0, symbol_table=0x0)
    at /tmp/php5-200405232030/Zend/zend_execute_API.c:550
#6  0x402654bd in zend_std_call_user_call (ht=3, return_value=0x8131084,
    this_ptr=0x812711c, return_value_used=1)
    at /tmp/php5-200405232030/Zend/zend_object_handlers.c:565
#7  0x402761da in zend_do_fcall_common_helper (execute_data=0xbfffd440,
    opline=0x81279b0, op_array=0x8126f64)