From 024850c8812e481e441d5d42673b9a33d89ec9ae Mon Sep 17 00:00:00 2001
From: Marko <marbar3778@yahoo.com>
Date: Tue, 9 May 2023 10:53:19 +0200
Subject: [PATCH] refactor(core): use working hash in finalizeblock instead of
 flush (#16065)

---
 baseapp/abci.go              | 33 ++++++++++++++++++++++++++-------
 client/grpc_query_test.go    |  2 +-
 testutil/sims/app_helpers.go |  2 +-
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/baseapp/abci.go b/baseapp/abci.go
index c901a859bf62..abe3271e79b7 100644
--- a/baseapp/abci.go
+++ b/baseapp/abci.go
@@ -702,8 +702,7 @@ func (app *BaseApp) FinalizeBlock(_ context.Context, req *abci.RequestFinalizeBl
 		TxResults:             txResults,
 		ValidatorUpdates:      endBlock.ValidatorUpdates,
 		ConsensusParamUpdates: &cp,
-		// TODO: Do not commit, but use current IAVL root hash!
-		AppHash: app.flushCommit().Hash,
+		AppHash:               app.workingHash(),
 	}, nil
 }
 
@@ -727,6 +726,8 @@ func (app *BaseApp) Commit(_ context.Context, _ *abci.RequestCommit) (*abci.Resp
 		rms.SetCommitHeader(header)
 	}
 
+	app.commit()
+
 	resp := &abci.ResponseCommit{
 		RetainHeight: retainHeight,
 	}
@@ -778,20 +779,38 @@ func (app *BaseApp) Commit(_ context.Context, _ *abci.RequestCommit) (*abci.Resp
 	return resp, nil
 }
 
-// flushCommit writes all state transitions that occurred during FinalizeBlock.
-// These writes are persisted to the root multi-store (app.cms) and flushed to
+// commit commits all state transitions that occurred during FinalizeBlock.
+// These writes have been persisted to the root multi-store (app.cms) via workingHash and flushed to
 // disk. This means when the ABCI client requests Commit(), the application
 // state transitions are already flushed to disk and as a result, we already have
 // an application Merkle root.
-func (app *BaseApp) flushCommit() storetypes.CommitID {
-	app.finalizeBlockState.ms.Write()
-
+// CONTRACT: must be called after workingHash is called.
+func (app *BaseApp) commit() storetypes.CommitID {
+	// call commit to persist data to disk
 	commitID := app.cms.Commit()
 	app.logger.Info("commit synced", "commit", fmt.Sprintf("%X", commitID))
 
 	return commitID
 }
 
+// workingHash gets the apphash that will be finalized in commit.
+// These writes will be persisted to the root multi-store (app.cms) and flushed to
+// disk in the Commit phase. This means when the ABCI client requests Commit(), the application
+// state transitions will be flushed to disk and as a result, but we already have
+// an application Merkle root.
+func (app *BaseApp) workingHash() []byte {
+	// Write the FinalizeBlock state into branched storage and commit the MultiStore.
+	// The write to the FinalizeBlock state writes all state transitions to the root
+	// MultiStore (app.cms) so when Commit() is called it persists those values.
+	app.finalizeBlockState.ms.Write()
+
+	// Get the hash of all writes in order to return the apphash to the comet in finalizeBlock.
+	commitHash := app.cms.WorkingHash()
+	app.logger.Debug("hash of all writes", "workingHash", fmt.Sprintf("%X", commitHash))
+
+	return commitHash
+}
+
 // halt attempts to gracefully shutdown the node via SIGINT and SIGTERM falling
 // back on os.Exit if both fail.
 func (app *BaseApp) halt() {
diff --git a/client/grpc_query_test.go b/client/grpc_query_test.go
index a4be61b9dc63..ef3afbd54386 100644
--- a/client/grpc_query_test.go
+++ b/client/grpc_query_test.go
@@ -91,7 +91,7 @@ func (s *IntegrationTestSuite) SetupSuite() {
 		},
 	)
 
-	// app.Commit(context.TODO(), &abci.RequestCommit{}) // TODO see if this is needed
+	app.Commit(context.TODO(), &abci.RequestCommit{})
 	app.FinalizeBlock(context.TODO(), &abci.RequestFinalizeBlock{
 		Height:             app.LastBlockHeight() + 1,
 		Hash:               app.LastCommitID().Hash,
diff --git a/testutil/sims/app_helpers.go b/testutil/sims/app_helpers.go
index 160265d4a1cc..b97c142c5877 100644
--- a/testutil/sims/app_helpers.go
+++ b/testutil/sims/app_helpers.go
@@ -166,7 +166,7 @@ func SetupWithConfiguration(appConfig depinject.Config, startupConfig StartupCon
 
 	// commit genesis changes
 	if !startupConfig.AtGenesis {
-		// app.Commit(context.TODO(), &abci.RequestCommit{}) // TODO figure out if this is needed?
+		app.Commit(context.TODO(), &abci.RequestCommit{})
 		_, err := app.FinalizeBlock(context.TODO(), &abci.RequestFinalizeBlock{
 			Height:             app.LastBlockHeight() + 1,
 			NextValidatorsHash: valSet.Hash(),