chenhg5/cc-connect · warning

yuanbao: empty data

Error message

yuanbao: empty data

What it means

parseFields is the low-level protobuf wire-format decoder for yuanbao frames; it rejects empty input with this error because there are no fields to parse. It indicates an upstream frame/message body that should contain data arrived empty.

Source

Thrown at platform/yuanbao/proto.go:133

func encodeConnMsgFull(cmdType int, cmd string, seqNo int, msgID string, module string, data []byte, needAck bool) []byte {
	b := newBuffer(128 + len(data))
	headBytes := (&buffer{}).writeHead(cmdType, cmd, seqNo, msgID, module, needAck, 0)
	b.writeBytesField(1, headBytes)
	if len(data) > 0 {
		b.writeBytesField(2, data)
	}
	return b.bytes()
}

type field struct {
	fieldNum int
	wireType int
	value    interface{}
}

func parseFields(data []byte) ([]field, error) {
	if len(data) == 0 {
		return nil, fmt.Errorf("yuanbao: empty data")
	}
	var fields []field
	pos := 0
	for pos < len(data) {
		tag, n := decodeVarint(data[pos:])
		if n == 0 {
			return nil, fmt.Errorf("yuanbao: parse varint tag failed at %d", pos)
		}
		pos += n
		fieldNum := int(tag >> 3)
		wt := int(tag & 0x07)
		switch wt {
		case wtVarint:
			val, n := decodeVarint(data[pos:])
			if n == 0 {
				return nil, fmt.Errorf("yuanbao: parse varint at %d", pos)
			}
			fields = append(fields, field{fieldNum, wt, val})

View on GitHub (pinned to 4000b2338a)

Solutions

1. Log the raw frame before decoding to see whether the server genuinely sent an empty body
2. Check the decompress/decrypt step upstream — empty output there usually means wrong key or corrupt payload
3. Guard decode paths to skip parseFields when the payload is legitimately empty (e.g. pure ack frames)
4. Retry the connection if the server persistently sends malformed frames

Example fix

// before
fields, err := parseFields(body)
// after
if len(body) == 0 { return nil } // empty ack frame, nothing to parse
fields, err := parseFields(body)

if len(data) == 0 { return nil /* nothing to parse */ }

fields, err := parseFields(data); if err != nil { if strings.Contains(err.Error(), "empty data") { return nil /* tolerate empty frames */ }; return fmt.Errorf("decode: %w", err) }

When it happens

Trigger: decodeConnMsg, decodeAuthBindRsp, decodeInboundPush, or decodeMsgBodyElement passing a zero-length byte slice into parseFields — e.g. an empty push payload from the server or a failed decrypt/decompress yielding no bytes.

Common situations: Server sends a heartbeat/ack frame with an empty body that the decoder incorrectly routes through a decode path expecting data; decompression or decryption step produced empty output; truncated network frame.

Understand the failure class

Background: "cannot parse invalid wire-format data", "cannot unmarshal", "failed unmarshalling": protobuf unmarshal errors explained — this error's family across 10 libraries.

Related errors

• yuanbao: parse varint tag failed at %d
• yuanbao: parse varint at %d
• yuanbao: parse length at %d
• yuanbao: length %d exceeds data at %d
• yuanbao: 64-bit truncated at %d

AI-assisted analysis of chenhg5/cc-connect@4000b2338a (2026-09-06). Data as JSON: /api/errors/d1fe070b40f627c0. Report an issue: GitHub.