fix: prevent nil lastcommitid hash (#18563)

baseapp/abci.go

@@ -2,7 +2,6 @@ package baseapp
 
 import (
 	"context"
-	"crypto/sha256"
 	"fmt"
 	"sort"
 	"strings"
@@ -126,28 +125,16 @@ func (app *BaseApp) InitChain(req *abci.RequestInitChain) (*abci.ResponseInitCha
 		}
 	}
 
-	// In the case of a new chain, AppHash will be the hash of an empty string.
-	// During an upgrade, it'll be the hash of the last committed block.
-	var appHash []byte
-	if !app.LastCommitID().IsZero() {
-		appHash = app.LastCommitID().Hash
-	} else {
-		// $ echo -n '' | sha256sum
-		// e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
-		emptyHash := sha256.Sum256([]byte{})
-		appHash = emptyHash[:]
-	}
-
 	// NOTE: We don't commit, but FinalizeBlock for block InitialHeight starts from
 	// this FinalizeBlockState.
 	return &abci.ResponseInitChain{
 		ConsensusParams: res.ConsensusParams,
 		Validators:      res.Validators,
-		AppHash:         appHash,
+		AppHash:         app.LastCommitID().Hash,
 	}, nil
 }
 
-func (app *BaseApp) Info(req *abci.RequestInfo) (*abci.ResponseInfo, error) {
+func (app *BaseApp) Info(_ *abci.RequestInfo) (*abci.ResponseInfo, error) {
 	lastCommitID := app.cms.LastCommitID()
 
 	return &abci.ResponseInfo{

baseapp/abci_test.go

@@ -3,6 +3,7 @@ package baseapp_test
 import (
 	"bytes"
 	"context"
+	"crypto/sha256"
 	"encoding/binary"
 	"encoding/hex"
 	"errors"
@@ -49,10 +50,12 @@ func TestABCI_Info(t *testing.T) {
 	res, err := suite.baseApp.Info(&reqInfo)
 	require.NoError(t, err)
 
+	emptyHash := sha256.Sum256([]byte{})
+	appHash := emptyHash[:]
 	require.Equal(t, "", res.Version)
 	require.Equal(t, t.Name(), res.GetData())
 	require.Equal(t, int64(0), res.LastBlockHeight)
-	require.Equal(t, []uint8(nil), res.LastBlockAppHash)
+	require.Equal(t, appHash, res.LastBlockAppHash)
 	require.Equal(t, suite.baseApp.AppVersion(), res.AppVersion)
 }
 
@@ -121,14 +124,11 @@ func TestABCI_InitChain(t *testing.T) {
 	// The AppHash returned by a new chain is the sha256 hash of "".
 	// $ echo -n '' | sha256sum
 	// e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
-	apphash, err := hex.DecodeString("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
+	emptyHash := sha256.Sum256([]byte{})
+	appHash := emptyHash[:]
 	require.NoError(t, err)
 
-	require.Equal(
-		t,
-		apphash,
-		initChainRes.AppHash,
-	)
+	require.Equal(t, appHash, initChainRes.AppHash)
 
 	// assert that chainID is set correctly in InitChain
 	chainID := getFinalizeBlockStateCtx(app).ChainID()

baseapp/baseapp_test.go

@@ -2,6 +2,7 @@ package baseapp_test
 
 import (
 	"context"
+	"crypto/sha256"
 	"fmt"
 	"math/rand"
 	"testing"
@@ -199,7 +200,9 @@ func TestLoadVersion(t *testing.T) {
 	err := app.LoadLatestVersion() // needed to make stores non-nil
 	require.Nil(t, err)
 
-	emptyCommitID := storetypes.CommitID{}
+	emptyHash := sha256.Sum256([]byte{})
+	appHash := emptyHash[:]
+	emptyCommitID := storetypes.CommitID{Hash: appHash}
 
 	// fresh store has zero/empty last commit
 	lastHeight := app.LastBlockHeight()
@@ -737,7 +740,10 @@ func TestLoadVersionPruning(t *testing.T) {
 	err := app.LoadLatestVersion() // needed to make stores non-nil
 	require.Nil(t, err)
 
-	emptyCommitID := storetypes.CommitID{}
+	emptyHash := sha256.Sum256([]byte{})
+	emptyCommitID := storetypes.CommitID{
+		Hash: emptyHash[:],
+	}
 
 	// fresh store has zero/empty last commit
 	lastHeight := app.LastBlockHeight()

go.mod

@@ -164,9 +164,7 @@ require (
 
 // Here are the short-lived replace from the Cosmos SDK
 // Replace here are pending PRs, or version to be tagged
-// replace (
-// 	<temporary replace>
-// )
+replace cosmossdk.io/store => ./store // TODO: REMOVE prior to release
 
 // Below are the long-lived replace of the Cosmos SDK
 replace (

go.sum

@@ -49,8 +49,6 @@ cosmossdk.io/log v1.2.1 h1:Xc1GgTCicniwmMiKwDxUjO4eLhPxoVdI9vtMW8Ti/uk=
 cosmossdk.io/log v1.2.1/go.mod h1:GNSCc/6+DhFIj1aLn/j7Id7PaO8DzNylUZoOYBL9+I4=
 cosmossdk.io/math v1.2.0 h1:8gudhTkkD3NxOP2YyyJIYYmt6dQ55ZfJkDOaxXpy7Ig=
 cosmossdk.io/math v1.2.0/go.mod h1:l2Gnda87F0su8a/7FEKJfFdJrM0JZRXQaohlgJeyQh0=
-cosmossdk.io/store v1.0.0 h1:6tnPgTpTSIskaTmw/4s5C9FARdgFflycIc9OX8i1tOI=
-cosmossdk.io/store v1.0.0/go.mod h1:ABMprwjvx6IpMp8l06TwuMrj6694/QP5NIW+X6jaTYc=
 cosmossdk.io/x/tx v0.12.0 h1:Ry2btjQdrfrje9qZ3iZeZSmDArjgxUJMMcLMrX4wj5U=
 cosmossdk.io/x/tx v0.12.0/go.mod h1:qTth2coAGkwCwOCjqQ8EAQg+9udXNRzcnSbMgGKGEI0=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=

store/CHANGELOG.md

@@ -23,15 +23,21 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 # Changelog
 
+## Unreleased
+
+### Bug Fixes
+
+* [#18563](https://github.com/cosmos/cosmos-sdk/pull/18563) `LastCommitID().Hash` will always return `sha256([]byte{})` if the store is empty.
+
 ## v1.0.0 (October 31, 2023)
 
 ### Features
 
 * [#17294](https://github.com/cosmos/cosmos-sdk/pull/17294) Add snapshot manager Close method.
 * [#15568](https://github.com/cosmos/cosmos-sdk/pull/15568) Migrate the `iavl` to the new key format.
-  * Remove `DeleteVersion`, `DeleteVersions`, `LazyLoadVersionForOverwriting` from `iavl` tree API.
-  * Add `DeleteVersionsTo` and `SaveChangeSet`, since it will keep versions sequentially like `fromVersion` to `toVersion`.
-  * Refactor the pruning manager to use `DeleteVersionsTo`.
+    * Remove `DeleteVersion`, `DeleteVersions`, `LazyLoadVersionForOverwriting` from `iavl` tree API.
+    * Add `DeleteVersionsTo` and `SaveChangeSet`, since it will keep versions sequentially like `fromVersion` to `toVersion`.
+    * Refactor the pruning manager to use `DeleteVersionsTo`.
 * [#15712](https://github.com/cosmos/cosmos-sdk/pull/15712) Add `WorkingHash` function to the store interface  to get the current app hash before commit.
 * [#14645](https://github.com/cosmos/cosmos-sdk/pull/14645) Add limit to the length of key and value.
 * [#15683](https://github.com/cosmos/cosmos-sdk/pull/15683) `rootmulti.Store.CacheMultiStoreWithVersion` now can handle loading archival states that don't persist any of the module stores the current state has.

store/rootmulti/store.go

@@ -1,6 +1,7 @@
 package rootmulti
 
 import (
+	"crypto/sha256"
 	"errors"
 	"fmt"
 	"io"
@@ -438,8 +439,19 @@ func (rs *Store) LatestVersion() int64 {
 // LastCommitID implements Committer/CommitStore.
 func (rs *Store) LastCommitID() types.CommitID {
 	if rs.lastCommitInfo == nil {
+		emptyHash := sha256.Sum256([]byte{})
+		appHash := emptyHash[:]
 		return types.CommitID{
 			Version: GetLatestVersion(rs.db),
+			Hash:    appHash, // set empty apphash to sha256([]byte{}) if info is nil
+		}
+	}
+	if len(rs.lastCommitInfo.CommitID().Hash) == 0 {
+		emptyHash := sha256.Sum256([]byte{})
+		appHash := emptyHash[:]
+		return types.CommitID{
+			Version: rs.lastCommitInfo.Version,
+			Hash:    appHash, // set empty apphash to sha256([]byte{}) if hash is nil
 		}
 	}
 

store/rootmulti/store_test.go

@@ -2,6 +2,7 @@ package rootmulti
 
 import (
 	"bytes"
+	"crypto/sha256"
 	"fmt"
 	"testing"
 	"time"
@@ -72,7 +73,9 @@ func TestCacheMultiStoreWithVersion(t *testing.T) {
 	err := ms.LoadLatestVersion()
 	require.Nil(t, err)
 
-	commitID := types.CommitID{}
+	emptyHash := sha256.Sum256([]byte{})
+	appHash := emptyHash[:]
+	commitID := types.CommitID{Hash: appHash}
 	checkStore(t, ms, commitID, commitID)
 
 	k, v := []byte("wind"), []byte("blows")
@@ -120,7 +123,9 @@ func TestHashStableWithEmptyCommit(t *testing.T) {
 	err := ms.LoadLatestVersion()
 	require.Nil(t, err)
 
-	commitID := types.CommitID{}
+	emptyHash := sha256.Sum256([]byte{})
+	appHash := emptyHash[:]
+	commitID := types.CommitID{Hash: appHash}
 	checkStore(t, ms, commitID, commitID)
 
 	k, v := []byte("wind"), []byte("blows")
@@ -148,8 +153,10 @@ func TestMultistoreCommitLoad(t *testing.T) {
 	err := store.LoadLatestVersion()
 	require.Nil(t, err)
 
+	emptyHash := sha256.Sum256([]byte{})
+	appHash := emptyHash[:]
 	// New store has empty last commit.
-	commitID := types.CommitID{}
+	commitID := types.CommitID{Hash: appHash}
 	checkStore(t, store, commitID, commitID)
 
 	// Make sure we can get stores by name.
@@ -744,7 +751,9 @@ func TestCommitOrdered(t *testing.T) {
 	err := multi.LoadLatestVersion()
 	require.Nil(t, err)
 
-	commitID := types.CommitID{}
+	emptyHash := sha256.Sum256([]byte{})
+	appHash := emptyHash[:]
+	commitID := types.CommitID{Hash: appHash}
 	checkStore(t, multi, commitID, commitID)
 
 	k, v := []byte("wind"), []byte("blows")

store/types/commit_info.go

@@ -1,6 +1,8 @@
 package types
 
 import (
+	"crypto/sha256"
+
 	cmtprotocrypto "github.com/cometbft/cometbft/proto/tendermint/crypto"
 
 	"cosmossdk.io/store/internal/maps"
@@ -30,10 +32,17 @@ func (ci CommitInfo) toMap() map[string][]byte {
 func (ci CommitInfo) Hash() []byte {
 	// we need a special case for empty set, as SimpleProofsFromMap requires at least one entry
 	if len(ci.StoreInfos) == 0 {
-		return nil
+		emptyHash := sha256.Sum256([]byte{})
+		return emptyHash[:]
 	}
 
 	rootHash, _, _ := maps.ProofsFromMap(ci.toMap())
+
+	if len(rootHash) == 0 {
+		emptyHash := sha256.Sum256([]byte{})
+		return emptyHash[:]
+	}
+
 	return rootHash
 }