Description:
------------
Ran a test script using pcntl_waitpid (below) to see if it could be interrupted via a signal.  The result was that the child process was not terminated upon sending the parent a signal.


Reproduce code:
---------------
#!/usr/local/bin/php -c/usr/local/lib/php.ini
<?php
declare(ticks = 1);
$child_pid = 0;

function sig_handler($signo) {
  global $child_pid;

  echo "got signal {$signo}\n";
  echo "Child pid = $child_pid\n";

  if ($child_pid != 0) {
    posix_kill($child_pid, SIGTERM);
  }
  exit(0);
}

if (!pcntl_signal(SIGTERM, "sig_handler", true))
     echo "did not install sigterm\n";

function run_child() {
  global $child_pid;

  $child_pid = pcntl_fork();

  if ($child_pid == -1) {
    echo "fork failed\n";
  } else if ($child_pid > 0) {
    echo "parent = " . getmypid() . "\n";
    echo "child = {$child_pid}\n";
    echo "waiting...\n";
    pcntl_waitpid($child_pid, $status);
  } else {
    $cmd = "/root/sigchild.sh";
    exec($cmd);
    echo "could not exec child";
  }
}

run_child();

?>

contents of sigchild.sh
!/bin/sh
sleep 100;
echo "done sleeping"


Expected result:
----------------
When a SIGTERM is sent to the parent process it should be handled by the signal handler and pass the signal to the child process, then exit.

Actual result:
--------------
when a SIGTERM is sent to the parent process it is not currently being handled, instead the child will continue to sleep and exit normally.