minus as prefix for xxhash64_hex() return value, sometimes <16 characters

[ghost]

Hi,

most of the time xxhash64_hex() returns 16xcharacters, but sometimes I'm getting minus sign as a 17th character and sometimes less then 16 characters:

perl -lE 'use Digest::xxHash qw(xxhash64_hex); say xxhash64_hex("b"x100000,89027)'
26be6c330380e6b8
# ^^^ 16 chars
perl -lE 'use Digest::xxHash qw(xxhash64_hex); say xxhash64_hex("b"x100000,890272)'
-2070116b240df563
# ^^^ minus char as prefix
$ perl -lE 'use Digest::xxHash qw(xxhash64_hex); $h = xxhash64_hex("b"x100000,89); say $h; say length($h)'
1aae2582443bbf0
# ^^^ 15 chars
$ whichpm Digest::xxHash
/opt/perl-5.22.0-live/lib/site_perl/5.22.0/x86_64-linux/Digest/xxHash.pm 2.03

xxhash64_hex() should be using uint64_to_hex() instead of int64_to_hex() to prevent the minus character.

Would be good if the variable hex string length is documented or that the hex string is zero padded to 16 characters as shaX_hex() friends do.

Best regards
Jozef