msgpack解码异常时，引起panic，rpcx没捕获异常，导致程序退出

[Leadrive]

panic: reflect: reflect.Value.SetString using unaddressable value

goroutine 106 [running]:
reflect.flag.mustBeAssignableSlow(0x98)
	C:/Go/src/reflect/value.go:260 +0x138
reflect.flag.mustBeAssignable(...)
	C:/Go/src/reflect/value.go:247
reflect.Value.SetString(0x10f3ba0, 0xc000392050, 0x98, 0xc000252f98, 0x8)
	C:/Go/src/reflect/value.go:1746 +0x37
github.com/vmihailenco/msgpack/v5.decodeStringValue(0xc000358cf0, 0x10f3ba0, 0xc000392050, 0x98, 0x10f3ba0, 0xc000392050)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_string.go:67 +0x8b
github.com/vmihailenco/msgpack/v5.(*Decoder).DecodeValue(0xc000358cf0, 0x10f3ba0, 0xc000392050, 0x98, 0xc000392050, 0x98)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode.go:309 +0x8e
github.com/vmihailenco/msgpack/v5.decodeInterfaceValue(0xc000358cf0, 0x11513a0, 0xc000316780, 0x194, 0x11513a0, 0x11)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_value.go:184 +0x9a
github.com/vmihailenco/msgpack/v5.(*Decoder).DecodeValue(0xc000358cf0, 0x11513a0, 0xc000316780, 0x194, 0x11513a0, 0xc000316780)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode.go:309 +0x8e
github.com/vmihailenco/msgpack/v5.decodeArrayValue(0xc000358cf0, 0x10fd780, 0xc000316780, 0x191, 0x10fd780, 0x17)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_slice.go:141 +0x134
github.com/vmihailenco/msgpack/v5.(*Decoder).DecodeValue(0xc000358cf0, 0x10fd780, 0xc000316780, 0x191, 0x10fd780, 0xc000316780)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode.go:309 +0x8e
github.com/vmihailenco/msgpack/v5.decodeSliceValue(0xc000358cf0, 0x10d5a00, 0xc0002b3a48, 0x197, 0x1, 0x1)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_slice.go:109 +0x205
github.com/vmihailenco/msgpack/v5.(*field).DecodeValue(0xc0002b2540, 0xc000358cf0, 0x120f9c0, 0xc0002b3a40, 0x199, 0x0, 0x0)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/types.go:118 +0x9a
github.com/vmihailenco/msgpack/v5.(*Decoder).decodeStruct(0xc000358cf0, 0x120f9c0, 0xc0002b3a40, 0x199, 0x4, 0xc0001cbac8, 0xa1e0b2)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_map.go:324 +0x24f
github.com/vmihailenco/msgpack/v5.decodeStructValue(0xc000358cf0, 0x120f9c0, 0xc0002b3a40, 0x199, 0x120f9c0, 0x17)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_map.go:282 +0x330
github.com/vmihailenco/msgpack/v5.(*Decoder).DecodeValue(0xc000358cf0, 0x120f9c0, 0xc0002b3a40, 0x199, 0x120f9c0, 0xc0002b3a40)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode.go:309 +0x8e
github.com/vmihailenco/msgpack/v5.decodeSliceValue(0xc000358cf0, 0x10d6500, 0xc0000c4418, 0x197, 0x1, 0x1)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_slice.go:109 +0x205
github.com/vmihailenco/msgpack/v5.(*field).DecodeValue(0xc000231d80, 0xc000358cf0, 0x12ba120, 0xc0000c43c0, 0x199, 0x0, 0x0)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/types.go:118 +0x9a
github.com/vmihailenco/msgpack/v5.(*Decoder).decodeStruct(0xc000358cf0, 0x12ba120, 0xc0000c43c0, 0x199, 0x11, 0xc0001cbcc8, 0xa1e0b2)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_map.go:324 +0x24f
github.com/vmihailenco/msgpack/v5.decodeStructValue(0xc000358cf0, 0x12ba120, 0xc0000c43c0, 0x199, 0x12ba120, 0x88)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode_map.go:282 +0x330
github.com/vmihailenco/msgpack/v5.(*Decoder).DecodeValue(0xc000358cf0, 0x12ba120, 0xc0000c43c0, 0x199, 0xc0000c43c0, 0x199)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode.go:309 +0x8e
github.com/vmihailenco/msgpack/v5.(*Decoder).Decode(0xc000358cf0, 0x12d0000, 0xc0000c43c0, 0x402fde, 0xc0001cbe57)
	C:/gowork/pkg/mod/github.com/vmihailenco/msgpack/v5@v5.3.4/decode.go:288 +0x178
github.com/smallnest/rpcx/codec.MsgpackCodec.Decode(0xc00009e5a3, 0x131, 0x131, 0x12d0000, 0xc0000c43c0, 0x3, 0xc0000a5ae0)
	C:/gowork/pkg/mod/github.com/smallnest/rpcx@v1.6.11/codec/codec.go:104 +0xd0
github.com/smallnest/rpcx/client.(*Client).input(0xc000372340)
	C:/gowork/pkg/mod/github.com/smallnest/rpcx@v1.6.11/client/client.go:697 +0x6d3
created by github.com/smallnest/rpcx/client.(*Client).Connect
	C:/gowork/pkg/mod/github.com/smallnest/rpcx@v1.6.11/client/connection.go:74 +0x1ee

在 C:/gowork/pkg/mod/github.com/smallnest/[email protected]/client/connection.go:74

go c.input()

msgpack解码异常，会引起panic，在线程中，没有捕获，会导致整个程序退出
vmihailenco/msgpack#309

[Leadrive]

在xclient.Call之前，把输出清一下，目前暂时不出现该错误了。
可能没清除，在解码时混一块了。
作者可以跟踪一下这个错误。

[smallnest]

需要一个简单例子复现问题。不清楚是rpcx问题还是vmihailenco/msgpack问题

[smallnest]

没有更详细的信息，无法确定问题所在，暂时close。
如果有确定的例子可以提供复现，请再打开此issue

[Aoang]

是 msgpack 的问题 (!

今天太晚了，就简单说说怎么复现。

func main() {
	type Data struct {
		Data1 *string
		Data2 *string
		Data3 *string
		Data4 *string
		Data5 *string
	}
	xClient := client.XClient{}

	go func() {
		data := &Data{}
		for i := 0; i < 100; i++ {
			xClient.Call(context.Background(), "name", nil, data)
		}
	}()
}

msgpack 编解码 data 时，会报 panic。

对于 msgpack 的细节可见 vmihailenco/msgpack#310

等有时间了，去提个 pr。建议警告一下用户。这个 bug ，由来已久。。。