common/buf/multi_buffer.go: Fix Compact()

[Fangliding]

#5014

之前的bug写成test case了

[Vdu6n1XMrq6694a8]

Thanks @Fangliding

I've test this branch and it does fix the #5012 👍

However, I can still logging like this:

[Info] [3437932928] app/proxyman/inbound: connection ends > proxy/vmess/inbound: connection ends > proxy/vmess/inbound: failed to transfer request > websocket: close 1000 (normal)

[patterniha]

10 hours non-stop debugging to find this bug

[patterniha]

@Fangliding

My code is full-compact, but your code is optimized-compact.

So your code doesn't compact some data.

For example your code doesn't merge the first data into second data in:
[8190,8192], [0, 1000], [0, 1000], ...

So, your code may send some small packets at beginning of the protocol, and this create a unique-characteristic that GFW can recognized.

[Fangliding]

@Fangliding

My code is full-compact, but your code is optimized-compact.

So your code doesn't compact some data.

For example your code doesn't merge the first data into second data in: [8190,8192], [0, 1000], [0, 1000], ...

So, your code may send some small packets at beginning of the protocol, and this create a unique-characteristic that GFW can recognized.

协议最开始的部分都是new出来空buf 你告诉我怎么compact出若干小包？这个函数就是尽力而为将碎片buf合并而已 目的是效率 如果真要硬能合多少合多少那应该是readall才对

[Fangliding]

bug修了就行 这没啥意义还难看 能是什么指纹 这都是用户产生的数据

[patterniha]

10 hours non-stop debugging to find this bug

after fixing about 30 bugs and at least 5 major bugs, and adding many features finally @Fangliding liked my comment :)