【BUG】发送超长消息时，空指针引用的错误

[LennyDream]

环境信息：
go-cqhttp版本: go-cqhttp-v0.9.40
运行环境: windows_amd64
连接方式: 反向WS

BUG内容：
问题重现：发送超长群聊消息时，解析时出现空指针引用

消息长度已超过10w字节,在千人群中调用get_group_member_list的json结果，直接发送群消息send_group_msg

// 1> MiriaGo类库中函数有问题 SendGroupMessage消息长度判断有问题
func (c *QQClient) SendGroupMessage(groupCode int64, m *message.SendingMessage, f ...bool) *message.GroupMessage {
	useFram := false
	if len(f) > 0 {
		useFram = f[0]
	}
	imgCount := m.Count(func(e message.IMessageElement) bool { return e.Type() == message.Image })
	if useFram {
		if m.Any(func(e message.IMessageElement) bool { return e.Type() == message.Reply }) {
			useFram = false
		}
	}
	msgLen := message.EstimateLength(m.Elements, 703)
	if msgLen > 5000 || imgCount > 50 { //!!这个条件应该走不到了,EstimateLength参数最长703限制
		return nil
	}
	if (msgLen > 100 || imgCount > 2) && !useFram {
		ret := c.sendGroupMessage(groupCode, false,
			&message.SendingMessage{Elements: []message.IMessageElement{
				c.uploadGroupLongMessage(groupCode,
					&message.ForwardMessage{Nodes: []*message.ForwardNode{
						{
							SenderId:   c.Uin,
							SenderName: c.Nickname,
							Time:       int32(time.Now().Unix()),
							Message:    m.Elements,
						},
					}},
				),
			}},
		)
		return &message.GroupMessage{
			Id:         ret.Id,
			InternalId: ret.InternalId,
			GroupCode:  ret.GroupCode,
			Sender:     ret.Sender,
			Time:       ret.Time,
			Elements:   m.Elements,
		}
	}
	return c.sendGroupMessage(groupCode, false, m)
}

// 2> 此函数返回nil
func (c *QQClient) multiMsgApplyUp(groupCode int64, data []byte, hash []byte, buType int32) (*multimsg.MultiMsgApplyUpRsp, []byte, error) {
	i, err := c.sendAndWait(c.buildMultiApplyUpPacket(data, hash, buType, utils.ToGroupUin(groupCode)))
	if err != nil { // !!此处直接返回错误,err内容 too large
		return nil, nil, err
	}
        //...
}

// 3> message.go:309 行,elem为nil
for _, elem := range elems {
	if e, ok := elem.(*ShortVideoElement); ok {
		r = e.Pack()
		break
	}
	if e, ok := elem.(IRichMessageElement); ok { // !!此处elem为nil
		r = append(r, e.Pack()...)
	}
}

调试堆栈如下
github.com/Mrs4s/MiraiGo/message.ToProtoElems at message.go:310
github.com/Mrs4s/MiraiGo/client.(*QQClient).buildGroupSendingPacket at group_msg.go:255
github.com/Mrs4s/MiraiGo/client.(*QQClient).sendGroupMessage at group_msg.go:129
github.com/Mrs4s/MiraiGo/client.(*QQClient).SendGroupMessage at group_msg.go:50
github.com/Mrs4s/go-cqhttp/coolq.(*CQBot).SendGroupMessage at bot.go:221
github.com/Mrs4s/go-cqhttp/coolq.(*CQBot).CQSendGroupMessage at api.go:239
github.com/Mrs4s/go-cqhttp/server.glob..func9 at websocket.go:413
github.com/Mrs4s/go-cqhttp/server.(*webSocketConn).handleRequest at websocket.go:333
runtime.goexit at asm_amd64.s:1374
Async stack trace
github.com/Mrs4s/go-cqhttp/server.(*WebSocketClient).listenAPI at websocket.go:185

报错日志信息
[2021-02-15 01:39:52] [INFO]: 处置WS命令时发生无法恢复的异常：runtime error: invalid memory address or nil pointer dereference
goroutine 14979 [running]:
runtime/debug.Stack(0x0, 0x0, 0x0)
E:/GoSDK/go1.15/src/runtime/debug/stack.go:24 +0xac
github.com/Mrs4s/go-cqhttp/server.(*webSocketConn).handleRequest.func1(0xc000ab1130)
E:/Code/02Go/01qqrobot/go-cqhttp-master/server/websocket.go:324 +0x6f
panic(0xf75aa0, 0x166e300)
E:/GoSDK/go1.15/src/runtime/panic.go:975 +0x414
github.com/Mrs4s/MiraiGo/message.(*ServiceElement).Pack(0x0, 0x16bfaf8, 0x0, 0x0)
E:/GoSDK/gopath/pkg/mod/github.com/!mrs4s/!mirai!go@v0.0.0-20210206134348-800bf525ed0e/message/pack.go:130 +0x86
github.com/Mrs4s/MiraiGo/message.ToProtoElems(0xc000be4060, 0x1, 0x1, 0x1, 0x0, 0x0, 0x0)
E:/GoSDK/gopath/pkg/mod/github.com/!mrs4s/!mirai!go@v0.0.0-20210206134348-800bf525ed0e/message/message.go:310 +0x1519
github.com/Mrs4s/MiraiGo/client.(*QQClient).buildGroupSendingPacket(0xc0004c6c00, 0x1a074257, 0x1d413b3f7, 0x0, 0x0, 0xc000be4060, 0x1, 0x1, 0xc000700000, 0x0, ...)
E:/GoSDK/gopath/pkg/mod/github.com/!mrs4s/!mirai!go@v0.0.0-20210206134348-800bf525ed0e/client/group_msg.go:255 +0x259
github.com/Mrs4s/MiraiGo/client.(*QQClient).sendGroupMessage(0xc0004c6c00, 0x1a074257, 0xc00042d200, 0xc00042d218, 0x0)
E:/GoSDK/gopath/pkg/mod/github.com/!mrs4s/!mirai!go@v0.0.0-20210206134348-800bf525ed0e/client/group_msg.go:129 +0xd2c
github.com/Mrs4s/MiraiGo/client.(*QQClient).SendGroupMessage(0xc0004c6c00, 0x1a074257, 0xc00042d940, 0xc000e6d2ea, 0x1, 0x1, 0x0)
E:/GoSDK/gopath/pkg/mod/github.com/!mrs4s/!mirai!go@v0.0.0-20210206134348-800bf525ed0e/client/group_msg.go:50 +0x4a5
github.com/Mrs4s/go-cqhttp/coolq.(*CQBot).SendGroupMessage(0xc00036ef00, 0x1a074257, 0xc000e6d940, 0x0)
E:/Code/02Go/01qqrobot/go-cqhttp-master/coolq/bot.go:221 +0x510
github.com/Mrs4s/go-cqhttp/coolq.(*CQBot).CQSendGroupMessage(0xc00036ef00, 0x1a074257, 0x107f440, 0xc00009c140, 0x0, 0x0)
E:/Code/02Go/01qqrobot/go-cqhttp-master/coolq/api.go:239 +0x335
github.com/Mrs4s/go-cqhttp/server.glob..func9(0xc00036ef00, 0x5, 0xc00170002d, 0x85f56, 0x0, 0x0, 0x0, 0x2d, 0x0)
E:/Code/02Go/01qqrobot/go-cqhttp-master/server/websocket.go:413 +0x2d6
github.com/Mrs4s/go-cqhttp/server.(*webSocketConn).handleRequest(0xc000ab1130, 0xc00036ef00, 0xc001600000, 0x85f85, 0xffe00)
E:/Code/02Go/01qqrobot/go-cqhttp-master/server/websocket.go:333 +0x509
created by github.com/Mrs4s/go-cqhttp/server.(*WebSocketClient).listenAPI
E:/Code/02Go/01qqrobot/go-cqhttp-master/server/websocket.go:185 +0x37a

[Mrs4s]

没想到会有人发这么长的消息...

[Mrs4s]

已修复