Integer overflow on a 64-bit system

[rybakit]

Unpacking 64-bit unsigned integer will result in a negative value if the value is bigger than 2^63 (as PHP does not support unsigned integers):

php > var_dump(msgpack_unpack("\xcf"."\xff\xff\xff\xff"."\xff\xff\xff\xff"));
int(-1)

But PHP's behavior in such cases is to fall back to float/double:

If PHP encounters a number beyond the bounds of the integer type, it will be interpreted as a float instead. Also, an operation which results in a number beyond the bounds of the integer type will return a float instead.

php > var_dump(PHP_INT_MAX + 1);
double(9.2233720368548E+18)
php > var_dump(hexdec('ffffffff'.'ffffffff'));
double(1.844674407371E+19)

I wonder if it would be reasonable to get msgpack_unpack() in line with PHP engine? Or return a string representation of the value?

[rybakit]

For the record, json_decode() by default casts uint32 values to float. And allows to pass the JSON_BIGINT_AS_STRING option to cast them to strings.

[andypost]

Got an issue with passing this test on 32-bits (x86) and PHP 7.4.8

msgpack-2.1.1/tests$ cat issue067.diff 
001+ string(19) "9223372036854775807"
001- int(9223372036854775807)

[andypost]

Any suggestion how to fix running this test?

[m6w6]

This test should probably not be run on x32, or be duplicated for x32 to test for the correct output.