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Fix RLP decoding for MorphTx #299

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Merged
FletcherMan merged 2 commits into from
Mar 17, 2026
Merged

Fix RLP decoding for MorphTx #299

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2a37b21
implement version-aware RLP decoding for MorphTx
SegueII Mar 17, 2026
623498a
fix morph tx
SegueII Mar 17, 2026
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33 changes: 33 additions & 0 deletions core/types/morph_tx.go
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Original file line number Diff line number Diff line change
Expand Up @@ -190,6 +190,39 @@ func (tx *MorphTx) EncodeRLP(w io.Writer) error {
return err
}

// DecodeRLP implements rlp.Decoder so that direct rlp.Decode calls use the
// version-aware decode logic instead of reflection-based struct decoding.
// Without this, the field order mismatch between MorphTx (which has Version
// before FeeTokenID) and the v0 wire format (which lacks Version) causes
// decode failures.
func (tx *MorphTx) DecodeRLP(s *rlp.Stream) error {
kind, _, err := s.Kind()
if err != nil {
return err
}
if kind == rlp.List {
// V0 format: data is a single RLP list
raw, err := s.Raw()
if err != nil {
return err
}
return decodeV0MorphTxRLP(tx, raw)
}
// V1+ format: version byte followed by RLP list
versionByte, err := s.Uint8()
if err != nil {
return err
}
if versionByte != MorphTxVersion1 {
return errors.New("unsupported morph tx version: " + strconv.Itoa(int(versionByte)))
}
Comment on lines +211 to +218
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@coderabbitai coderabbitai Bot Mar 17, 2026

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⚠️ Potential issue | 🟡 Minor

Keep DecodeRLP aligned with decode() for the 0x00 V0 form.

Line 296 still routes a leading 0x00 to the V0 decoder, but Lines 216-218 reject the same input as an unsupported version. Right now rlp.DecodeBytes and decode() do not accept the same byte streams.

Also applies to: 292-305

🤖 Prompt for AI Agents 
Verify each finding against the current code and only fix it if needed.

In `@core/types/morph_tx.go` around lines 211 - 218, DecodeRLP currently rejects a
leading 0x00 version byte while decode() treats 0x00 as the V0 form; change the
version handling in DecodeRLP so that when reading versionByte via s.Uint8() a
value of 0x00 is routed to the existing V0 decoder (same behavior as decode()),
allow MorphTxVersion1 to continue to be handled as the V1 path, and only return
an unsupported-version error for other bytes. Update the same logic block
referenced around the other occurrence (lines ~292-305) so both DecodeRLP and
decode() accept identical byte streams; refer to the symbols versionByte,
MorphTxVersion1, DecodeRLP and decode() to locate and update the checks.

raw, err := s.Raw()
if err != nil {
return err
}
return decodeV1MorphTxRLP(tx, raw)
Comment on lines +209 to +223
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@coderabbitai coderabbitai Bot Mar 17, 2026

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⚠️ Potential issue | 🟠 Major

Reset version-specific fields before decoding into a reused receiver.

DecodeRLP now fills the caller-supplied MorphTx, but decodeV0MorphTxRLP never restores Version/Reference/Memo, and decodeV1MorphTxRLP only assigns Reference/Memo when the new payload is non-empty. Decode V1(with memo) followed by V0 or V1 minimal into the same instance and the stale V1 state survives, which then drives the wrong downstream behavior.

Suggested fix 
func decodeV1MorphTxRLP(tx *MorphTx, blob []byte) error {
	var v1 v1MorphTxRLP
	if err := rlp.DecodeBytes(blob, &v1); err != nil {
		return err
	}

+	tx.Reference = nil
+	tx.Memo = nil
 	tx.ChainID = v1.ChainID
 	tx.Nonce = v1.Nonce
 	tx.GasTipCap = v1.GasTipCap
 	tx.GasFeeCap = v1.GasFeeCap
 	tx.Gas = v1.Gas
 	tx.To = v1.To
 	tx.Value = v1.Value
 	tx.Data = v1.Data
 	tx.AccessList = v1.AccessList
 	tx.Version = MorphTxVersion1
 	tx.FeeTokenID = v1.FeeTokenID
 	tx.FeeLimit = v1.FeeLimit
 	// Convert []byte to *common.Reference
 	if len(v1.Reference) != 0 && len(v1.Reference) != common.ReferenceLength {
 		return errors.New("invalid reference length: expected 0 or " + strconv.Itoa(common.ReferenceLength) + ", got " + strconv.Itoa(len(v1.Reference)))
 	}
 	if len(v1.Reference) == common.ReferenceLength {
 		ref := common.BytesToReference(v1.Reference)
 		tx.Reference = &ref
 	}
 	// Convert []byte to *[]byte and validate memo length
 	if len(v1.Memo) > common.MaxMemoLength {
 		return errors.New("memo exceeds maximum length of " + strconv.Itoa(common.MaxMemoLength) + " bytes, got " + strconv.Itoa(len(v1.Memo)))
 	}
 	if len(v1.Memo) > 0 {
 		tx.Memo = &v1.Memo
 	}
 	tx.V = v1.V
 	tx.R = v1.R
 	tx.S = v1.S

 	return nil
}

func decodeV0MorphTxRLP(tx *MorphTx, blob []byte) error {
	var v0 v0MorphTxRLP
	if err := rlp.DecodeBytes(blob, &v0); err != nil {
		return err
	}

	if v0.FeeTokenID == 0 {
		return errors.New("invalid fee token id, expected non-zero")
	}

+	tx.Version = MorphTxVersion0
+	tx.Reference = nil
+	tx.Memo = nil
 	tx.ChainID = v0.ChainID
 	tx.Nonce = v0.Nonce
 	tx.GasTipCap = v0.GasTipCap
 	tx.GasFeeCap = v0.GasFeeCap
 	tx.Gas = v0.Gas
 	tx.To = v0.To
 	tx.Value = v0.Value
 	tx.Data = v0.Data
 	tx.AccessList = v0.AccessList
 	tx.FeeTokenID = v0.FeeTokenID
 	tx.FeeLimit = v0.FeeLimit
 	tx.V = v0.V
 	tx.R = v0.R
 	tx.S = v0.S

 	return nil
}

Also applies to: 314-340, 348-373

🤖 Prompt for AI Agents 
Verify each finding against the current code and only fix it if needed.

In `@core/types/morph_tx.go` around lines 209 - 223, Before decoding into a
potentially reused MorphTx, clear version-specific state so stale V1 data
doesn't survive: in DecodeRLP (the function that calls
decodeV0MorphTxRLP/decodeV1MorphTxRLP) set tx.Version = 0 and tx.Reference = nil
and tx.Memo = nil before branching; when you detect a V1 versionByte, set
tx.Version = MorphTxVersion1 after validation and before calling
decodeV1MorphTxRLP. Apply the same reset pattern to the other decoding
entry-points referenced (the blocks that call
decodeV0MorphTxRLP/decodeV1MorphTxRLP at the other locations noted) so
decodeV0MorphTxRLP and decodeV1MorphTxRLP never accidentally inherit prior
Reference/Memo values.

}

func (tx *MorphTx) encode(b *bytes.Buffer) error {
switch tx.Version {
case MorphTxVersion0:
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