Handling int<lenenc> values greater than 2^63-1 in MySQL OKPackets and related packets

[jchrys]

Issue Description

It has come to our attention that MySQL's OKPackets and other packets containing int<lenenc> types may potentially have values greater than 2^63-1. As per the MySQL documentation, int<lenenc> supports such values.

Current Implementation

Our current implementation does not take this into account, and we need to address this issue to ensure proper handling of int<lenenc> values exceeding 2^63-1.

Impact on Real-world Usage

It is worth noting that this issue does not have a significant impact on real-world usage. Nonetheless, when converting the value to a string representation, it might be presented as a negative number.

Proposed Solution

To enhance the accuracy and reliability of our implementation, we need to implement a patch that properly handles int<lenenc> values exceeding 2^63-1.

[mirromutth]

This is caused by VarIntUtils.readVarInt trying to read 8 bytes and returning it directly as an integer for performance reasons, which should theoretically be wrapped with an object (such as writing an UnsignedLong or using a BigInteger).

However, this lower-level decoding operation may affect performance if using wrapper classes. Maybe add some code comments to inform the developer how the return value should be used instead of using a wrapper class.

[jchrys]

Resolved by @mirromutth (#161, #168 )