priv validator returns last sign bytes if h/r/s matches

since now we have time in the msgs and we might crash between writing
the priv val and writing to wal.

Refs #984

types/priv_validator.go

@@ -193,8 +193,8 @@ func (privVal *PrivValidatorFS) Reset() {
 	privVal.Save()
 }
 
-// SignVote signs a canonical representation of the vote, along with the chainID.
-// Implements PrivValidator.
+// SignVote signs a canonical representation of the vote, along with the
+// chainID. Implements PrivValidator.
 func (privVal *PrivValidatorFS) SignVote(chainID string, vote *Vote) error {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
@@ -206,8 +206,8 @@ func (privVal *PrivValidatorFS) SignVote(chainID string, vote *Vote) error {
 	return nil
 }
 
-// SignProposal signs a canonical representation of the proposal, along with the chainID.
-// Implements PrivValidator.
+// SignProposal signs a canonical representation of the proposal, along with
+// the chainID. Implements PrivValidator.
 func (privVal *PrivValidatorFS) SignProposal(chainID string, proposal *Proposal) error {
 	privVal.mtx.Lock()
 	defer privVal.mtx.Unlock()
@@ -219,40 +219,36 @@ func (privVal *PrivValidatorFS) SignProposal(chainID string, proposal *Proposal)
 	return nil
 }
 
-// signBytesHRS signs the given signBytes if the height/round/step (HRS)
-// are greater than the latest state. If the HRS are equal,
-// it returns the privValidator.LastSignature.
+// signBytesHRS signs the given signBytes if the height/round/step (HRS) are
+// greater than the latest state. If the HRS are equal, it returns the
+// privValidator.LastSignature.
 func (privVal *PrivValidatorFS) signBytesHRS(height int64, round int, step int8, signBytes []byte) (crypto.Signature, error) {
-
 	sig := crypto.Signature{}
-	// If height regression, err
+
 	if privVal.LastHeight > height {
 		return sig, errors.New("Height regression")
 	}
-	// More cases for when the height matches
+
 	if privVal.LastHeight == height {
-		// If round regression, err
 		if privVal.LastRound > round {
 			return sig, errors.New("Round regression")
 		}
-		// If step regression, err
+
 		if privVal.LastRound == round {
 			if privVal.LastStep > step {
 				return sig, errors.New("Step regression")
 			} else if privVal.LastStep == step {
 				if privVal.LastSignBytes != nil {
 					if privVal.LastSignature.Empty() {
-						cmn.PanicSanity("privVal: LastSignature is nil but LastSignBytes is not!")
-					}
-					// so we dont sign a conflicting vote or proposal
-					// NOTE: proposals are non-deterministic (include time),
-					// so we can actually lose them, but will still never sign conflicting ones
-					if bytes.Equal(privVal.LastSignBytes, signBytes) {
-						// log.Notice("Using privVal.LastSignature", "sig", privVal.LastSignature)
-						return privVal.LastSignature, nil
+						panic("privVal: LastSignature is nil but LastSignBytes is not!")
 					}
+					// NOTE: we might crash between writing the priv val and writing to
+					// wal. since we have time in votes and proposals, signBytes can be
+					// different from LastSignBytes. we might be signing conflicting
+					// bytes here.
+					return privVal.LastSignature, nil
 				}
-				return sig, errors.New("Step regression")
+				return sig, errors.New("No LastSignature found")
 			}
 		}
 	}

types/priv_validator_test.go

@@ -99,7 +99,6 @@ func TestSignVote(t *testing.T) {
 	privVal := GenPrivValidatorFS(tempFilePath)
 
 	block1 := BlockID{[]byte{1, 2, 3}, PartSetHeader{}}
-	block2 := BlockID{[]byte{3, 2, 1}, PartSetHeader{}}
 	height, round := int64(10), 1
 	voteType := VoteTypePrevote
 
@@ -117,7 +116,6 @@ func TestSignVote(t *testing.T) {
 		newVote(privVal.Address, 0, height, round-1, voteType, block1),   // round regression
 		newVote(privVal.Address, 0, height-1, round, voteType, block1),   // height regression
 		newVote(privVal.Address, 0, height-2, round+4, voteType, block1), // height regression and different round
-		newVote(privVal.Address, 0, height, round, voteType, block2),     // different block
 	}
 
 	for _, c := range cases {
@@ -133,7 +131,6 @@ func TestSignProposal(t *testing.T) {
 	privVal := GenPrivValidatorFS(tempFilePath)
 
 	block1 := PartSetHeader{5, []byte{1, 2, 3}}
-	block2 := PartSetHeader{10, []byte{3, 2, 1}}
 	height, round := int64(10), 1
 
 	// sign a proposal for first time
@@ -150,7 +147,6 @@ func TestSignProposal(t *testing.T) {
 		newProposal(height, round-1, block1),   // round regression
 		newProposal(height-1, round, block1),   // height regression
 		newProposal(height-2, round+4, block1), // height regression and different round
-		newProposal(height, round, block2),     // different block
 	}
 
 	for _, c := range cases {