I cannot reproduce this with PHP 8.0.13 with Apache 2.4 (mod_php)
on Windows.

I doubt this is a valid expression for your ternary operator, also with this code the integer value change for error_reporting occurs?

error_reporting(E_ALL);

class Foo
{
    public $a;

    public function seta($a) {
        $b = @random_int(16, 16);
            if(is_int($b))
            $this->a = $b;
        return $a;
}
    public function numbera() {
    return $this->a;
}
}

$c = new Foo();
$c->seta(0);
$var = $c->numbera();
if($var != 16)
echo 'bug' . PHP_EOL;
else
echo 'normal' . PHP_EOL;
var_dump($var, error_reporting(), @error_reporting());

The @ operator will no longer silence fatal errors (E_ERROR == 1, E_CORE_ERROR == 4, E_COMPILE_ERROR == 64, E_USER_ERROR == 256, E_RECOVERABLE_ERROR == 4096, E_PARSE == 4)
https://www.php.net/manual/en/migration80.incompatible.php

I was able to reproduce this in a fresh Ubuntu 20.04 setup, here are reproduction steps which should work starting from spinning up fresh Ubuntu 20.04 on Amazon EC2.

Interesting, the issue doesn't always happen if you hit the file immediately after creating it, even if you hit it multiple times immediately after creating it, a small delay is necessary.

Test Process
--------------------



sudo su
add-apt-repository ppa:ondrej/php
apt-get update
apt-get upgrade
apt-get install php8.0-fpm apache2 
a2enmod proxy_fcgi
rm /etc/apache2/sites-enabled/000-default.conf
cat /etc/apache2/sites-available/000-default.conf | grep -v "</VirtualHost>" > /etc/apache2/sites-enabled/000-default.conf
cat >>/etc/apache2/sites-enabled/000-default.conf <<'EOF'
   <FilesMatch "\.php$">
    <If "-f %{REQUEST_FILENAME}">
        SetHandler "proxy:unix:/var/run/php/php8.0-fpm.sock|fcgi://localhost/"
    </If>
  </FilesMatch>
</VirtualHost>
EOF

service apache2 restart

cat >/var/www/html/test-1.php <<'EOF'
<?php

error_reporting(E_ALL);

class Foo
{
    public $a;

    public function bar() {
        $this->a = (true) ? @random_int(0, 100) : false;
    }
}


echo "Should Equal 32767: " . error_reporting() . "\n";

$c = new Foo();
$c->bar();

echo "Should Equal 32767: " . error_reporting() . "\n";

EOF

echo "Sleeping 2 seconds to more reliably trigger the issue..."
sleep 2
for x in 1 2 3 4 ; do curl http://localhost/test-1.php; done



----------

I'll add also that the test case can be simplified to

----------

<?php

error_reporting(E_ALL);

echo "Should Equal 32767: " . error_reporting() . "\n";

$a = true;
$b = $a ? @random_int(0,100) : false;

echo "Should Equal 32767: " . error_reporting() . "\n";

----------


It seems to the ternary which is the critical factor in producing the error.

Final note, I can also reproduce in PHP 8.1 (adjust reproduction script as appropriate).

Do you have OPcache enabled?  Maybe even JIT?  Is it reproducible
without OPcache?

I can repro with opcache.

The QM_ASSIGN to T0 is eliminated, even though there is a read of T0 in between:

Foo::bar:
     ; (lines=10, args=0, vars=0, tmps=2, ssa_vars=3, no_loops)
     ; (after dce pass)
     ; /home/nikic/php/php-src/t484.php:6-8
     ; return  [null] RANGE[0..0]
BB0:
     ; start exit lines=[0-9]
     ; level=0
0000 #0.T0 [long] = BEGIN_SILENCE
0001 INIT_FCALL 2 112 string("random_int")
0002 SEND_VAL int(0) 1
0003 SEND_VAL int(100) 2
0004 #1.V1 [long] = DO_ICALL
0005 END_SILENCE #0.T0 [long]
0006 #2.T0 [long] = QM_ASSIGN #1.V1 [long]
0007 ASSIGN_OBJ THIS string("a")
0008 OP_DATA #2.T0 [long]
0009 RETURN null

Foo::bar:
     ; (lines=9, args=0, vars=0, tmps=2, ssa_vars=3, no_loops)
     ; (after dfa pass)
     ; /home/nikic/php/php-src/t484.php:6-8
     ; return  [null] RANGE[0..0]
BB0:
     ; start exit lines=[0-8]
     ; level=0
0000 #0.T0 [long] = BEGIN_SILENCE
0001 INIT_FCALL 2 112 string("random_int")
0002 SEND_VAL int(0) 1
0003 SEND_VAL int(100) 2
0004 #2.T0 [long] = DO_ICALL
0005 END_SILENCE #0.T0 [long]
0006 ASSIGN_OBJ THIS string("a")
0007 OP_DATA #2.T0 [long]
0008 RETURN null