Segmentation fault when calling inside __callStatic with arguments

[oraoto]

Environment:

• lib-ffi: 3.2.1
• php-ffi: latest master
• php version: latest PHP-7.4 (php/php-src@76f8a90)

<?php

class Test
{
    private static $ffi;

    private static function createFFI()
    {
        $cdef="
            int abs(int n);
        ";
        static::$ffi = FFI::cdef($cdef, "libc.so.6");
    }

    private static function getFFI()
    {
        if (!static::$ffi) {
            static::createFFI();
        }
        return static::$ffi;
    }

    public static function __callStatic($method, $args)
    {
        $ffi = static::getFFI();
        return $ffi->abs(-1);
    }

    public static function absDirect()
    {
        // same as __callStatic
        $ffi = static::getFFI();
        return $ffi->abs(-1);
    }

}

When calling absDirect or __callStatic without arguments, it works correctly:

// call absDirect
echo Test::absDirect(); // 1
echo Test::absDirect(); // 1

// __callStatic with no argument
echo Test::abs(); // 1
echo Test::abs(); // 1

However, __callStatic with arguments will segfault on the second call, event we don't use the arguments at all:

echo Test::abs(-1); // 1
echo Test::abs(-1); // segfault

[dstogov]

Thanks far catching.
ext/ffi is already merged into PHP-7.4 and master.
I've just fixed the problem in the php repository.