fix: buffer not send

[winking324]

1. 应该在 ready 事件触发时，把 buffer 中的消息继续发送出去，以防止没有新的消息过来，buffer 中的消息也不主动发送
2. 当其中某一个 packet 发送失败或者出错时，不影响 buffer 中其他 packet 继续发送

fixes zishang520/socket.io#101

[zishang520]

Well done. I will review it first to ensure it does not cause any new issues.

[zishang520]

Looking forward to your response.

[zishang520]

Please hold on while I reassess the new content you submitted.

[winking324]

Hi, how is the review going? Is there anything else that needs to be revised?

[zishang520]

Removing s.server.Emit("drain", s) and s.Emit("drain") will cause

engine.io/engine/socket.go

Lines 562 to 565 in 52d56d1

	s.Once("drain", func(...any) {
	socket_log.Debug("all packets have been sent, closing the transport")
	s.closeTransport(discard)
	})

to fail to execute properly.

[zishang520]

This repository and its history have been merged into the Socket.IO monorepo.