A Docker container to confirm the bug : https://bugs.php.net/bug.php?id=63426

Dockerfile

FROM debian

RUN apt-get update && apt-get install -y libapache2-mod-php5 php5-xdebug nano vim
RUN a2enmod php5
RUN rm /var/www/html/index.html

COPY index.php /var/www/html/index.php
COPY test.php /var/www/html/test.php

ADD start.sh /root/start.sh
RUN chmod +x /root/start.sh

EXPOSE 80

CMD ["/root/start.sh"]

index.php

<?php

if (@$_GET['txt']) { 
    foreach (ini_get_all() as $key => $value) {
        print "$key = ".json_encode($value)."\n";
    }
} else {
    phpinfo();
}

start.sh

#!/bin/bash

source /etc/apache2/envvars
exec apache2 -D FOREGROUND

test.php

<?php

header('Charset: utf-8');

try {
    // this don't work, you should not even go in the catch block
    throw new Exception("C'est pas p" . html_entity_decode("&agrave;t&eacute;", ENT_COMPAT | ENT_HTML401, 'ISO-8859-1'));
    // if you skip the first exception, this one is ok will not segfault
    throw new Exception("C'est pas p" . html_entity_decode("&agrave;t&eacute;", ENT_COMPAT | ENT_HTML401, 'utf-8'));
} catch (\Exception $e) {
    print $e->getMessage();
}