update spec for Merkle RFC 6962 (#3175)

* spec: specify when MerkleRoot is on hashes

* remove unnecessary hash methods

* update changelog

* fix test

types/results.go

@@ -3,25 +3,20 @@ package types
 import (
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/crypto/merkle"
-	"github.com/tendermint/tendermint/crypto/tmhash"
 	cmn "github.com/tendermint/tendermint/libs/common"
 )
 
 //-----------------------------------------------------------------------------
 
 // ABCIResult is the deterministic component of a ResponseDeliverTx.
-// TODO: add Tags
+// TODO: add tags and other fields
+// https://github.com/tendermint/tendermint/issues/1007
 type ABCIResult struct {
 	Code uint32       `json:"code"`
 	Data cmn.HexBytes `json:"data"`
 }
 
-// Hash returns the canonical hash of the ABCIResult
-func (a ABCIResult) Hash() []byte {
-	bz := tmhash.Sum(cdcEncode(a))
-	return bz
-}
-
+// Bytes returns the amino encoded ABCIResult
 func (a ABCIResult) Bytes() []byte {
 	return cdcEncode(a)
 }

types/results_test.go

@@ -16,20 +16,21 @@ func TestABCIResults(t *testing.T) {
 	e := ABCIResult{Code: 14, Data: []byte("foo")}
 	f := ABCIResult{Code: 14, Data: []byte("bar")}
 
-	// Nil and []byte{} should produce the same hash.
-	require.Equal(t, a.Hash(), a.Hash())
-	require.Equal(t, b.Hash(), b.Hash())
-	require.Equal(t, a.Hash(), b.Hash())
+	// Nil and []byte{} should produce the same bytes
+	require.Equal(t, a.Bytes(), a.Bytes())
+	require.Equal(t, b.Bytes(), b.Bytes())
+	require.Equal(t, a.Bytes(), b.Bytes())
 
 	// a and b should be the same, don't go in results.
 	results := ABCIResults{a, c, d, e, f}
 
-	// Make sure each result hashes properly.
+	// Make sure each result serializes differently
 	var last []byte
-	for i, res := range results {
-		h := res.Hash()
-		assert.NotEqual(t, last, h, "%d", i)
-		last = h
+	assert.Equal(t, last, a.Bytes()) // first one is empty
+	for i, res := range results[1:] {
+		bz := res.Bytes()
+		assert.NotEqual(t, last, bz, "%d", i)
+		last = bz
 	}
 
 	// Make sure that we can get a root hash from results and verify proofs.

types/validator.go

@@ -4,8 +4,6 @@ import (
 	"bytes"
 	"fmt"
 
-	"github.com/tendermint/tendermint/crypto/tmhash"
-
 	"github.com/tendermint/tendermint/crypto"
 	cmn "github.com/tendermint/tendermint/libs/common"
 )
@@ -70,12 +68,6 @@ func (v *Validator) String() string {
 		v.ProposerPriority)
 }
 
-// Hash computes the unique ID of a validator with a given voting power.
-// It excludes the ProposerPriority value, which changes with every round.
-func (v *Validator) Hash() []byte {
-	return tmhash.Sum(v.Bytes())
-}
-
 // Bytes computes the unique encoding of a validator with a given voting power.
 // These are the bytes that gets hashed in consensus. It excludes address
 // as its redundant with the pubkey. This also excludes ProposerPriority