[XLC++ 9.0] std::uncaught_exception() false in terminate handler

According to 18.6.4, p1, std::uncaught_exception() is required to return true when terminate() is entered for any reason other than an explicit call to terminate(), and to continue to return true while executing the installed terminate handler. The program below shows that the XLC++ 9.0 implementation fails to follow this requirement:

$ cat uncaught.cpp && xlC -qversion && xlC uncaught.cpp && ./a.out
#include <exception>
#include <stdio.h>
#include <stdlib.h>

bool expect_uncaught;
const char* which;

void handler ()
{
const bool uncaught = std::uncaught_exception ();

printf ("%s handler: uncaught_exception () == %d, got %d\n",
which, expect_uncaught, uncaught);

exit (expect_uncaught == uncaught ? 0 : 1);
}

void invoke_unexpected () throw ()

{ throw 0; }

void test_unexpected ()
{
puts ("testing uncaught_exception() after a call to unexpected()");

std::set_unexpected (handler);

expect_uncaught = false;
which = "unexpected";
invoke_unexpected ();
}

int evaluate (int select)
{
if (2 == select)

{ expect_uncaught = true; throw 0; }

else if (3 == select)
std::terminate ();
else
std::unexpected ();

return 0;
}

void test_terminate (int select)
{
printf ("uncaught_exception() after an %s call to %s\n",
2 == select ? "implicit" : "explicit",
select < 4 ? "terminate()" : "unexpected() during a throw");

std::set_terminate (handler);
which = "terminate";

throw evaluate (select);
}

int main (int argc, char *argv[])
{
if (1 == argc)

{ printf ("%s\n", system ("./a.out 1") ? "FAIL" : "PASS"); printf ("%s\n", system ("./a.out 2") ? "FAIL" : "PASS"); printf ("%s\n", system ("./a.out 3") ? "FAIL" : "PASS"); printf ("%s\n", system ("./a.out 4") ? "FAIL" : "PASS"); }

else

{ int select = argv [1][0] - '0'; 1 < select ? test_terminate (select) : test_unexpected (); }

}
IBM XL C/C++ Enterprise Edition for AIX, V9.0
Version: 09.00.0000.0000
testing uncaught_exception() after a call to unexpected()
unexpected handler: uncaught_exception () == 0, got 0
PASS
uncaught_exception() after an implicit call to terminate()
terminate handler: uncaught_exception () == 1, got 0
FAIL
uncaught_exception() after an explicit call to terminate()
terminate handler: uncaught_exception () == 0, got 0
PASS
uncaught_exception() after an explicit call to unexpected() during a throw
terminate handler: uncaught_exception () == 0, got 0
PASS