Description:
------------
The included CLI test script forks a child process and should terminate when the child process finishes after two seconds with the message that SIGCHLD signal (17) was received. This works as expected on my Fedora system with PHP 5.3.3-1 installed, but the process never receives SIGCHLD on my CentOS system with identically built PHP 5.3.3-1.

The configure line for the CentOS system is the one below, the Fedora one is the same except for some differences in paths but not options:
'./configure' '--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu' '--target=x86_64-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib64' '--libexecdir=/usr/libexec' '--localstatedir=/var' '--sharedstatedir=/usr/com' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--cache-file=../config.cache' '--with-libdir=lib64' '--with-config-file-path=/etc' '--with-config-file-scan-dir=/etc/php.d' '--disable-debug' '--with-pic' '--disable-rpath' '--without-pear' '--with-bz2' '--with-exec-dir=/usr/bin' '--with-freetype-dir=/usr' '--with-png-dir=/usr' '--with-xpm-dir=/usr' '--enable-gd-native-ttf' '--with-t1lib=/usr' '--without-gdbm' '--with-gettext' '--with-gmp' '--with-iconv' '--with-jpeg-dir=/usr' '--with-openssl' '--with-pcre-regex=/usr' '--with-zlib' '--with-layout=GNU' '--enable-exif' '--enable-ftp' '--enable-magic-quotes' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-sysvmsg' '--with-kerberos' '--enable-ucd-snmp-hack' '--enable-shmop' '--enable-calendar' '--with-libxml-dir=/usr' '--enable-xml' '--with-apxs2=/usr/sbin/apxs' '--without-mysql' '--without-gd' '--disable-dom' '--disable-dba' '--without-unixODBC' '--disable-pdo' '--disable-xmlreader' '--disable-xmlwriter' '--without-sqlite' '--without-sqlite3' '--disable-phar' '--disable-fileinfo' '--disable-json' '--without-pspell' '--disable-wddx' '--without-curl' '--disable-posix' '--disable-sysvmsg' '--disable-sysvshm' '--disable-sysvsem'  

I rebuilt the CentOS PHP with explicit option --disable-sigchld but that didn't help, it is the default after all.

Test script:
---------------
<?php
if (($pid = pcntl_fork()) === 0)
  usleep(2000000);
else if ($pid !== -1)
{
  $signals = array(SIGINT, SIGCHLD);
  pcntl_sigprocmask(SIG_BLOCK, $signals, $prevSignals);
  $signal = pcntl_sigwaitinfo($signals, $info);
  echo "received signal ${signal}\n";
}


Expected result:
----------------
> php test.php
received signal 17

Actual result:
--------------
> php test.php
process runs forever until SIGINT is received (CTRL+C), the child process is defunct after two seconds