From 7a43e490669f8073d0f93d06afaeb3758325d2b7 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Mon, 18 Dec 2023 19:25:10 +0100
Subject: [PATCH] fix(baseapp): Reset GasMeter before deliverTX (backport
 #18714) (#18774)

---
 CHANGELOG.md            |  4 ++++
 baseapp/abci.go         |  4 ++++
 baseapp/baseapp_test.go | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e183a9544f6..86d78ed61fd1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -43,6 +43,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/gov) [#18707](https://github.com/cosmos/cosmos-sdk/pull/18707) Improve genesis validation.
 * (x/auth/tx) [#18772](https://github.com/cosmos/cosmos-sdk/pull/18772) Remove misleading gas wanted from tx simulation failure log.
 
+### Bug Fixes
+
+* (baseapp) [#18609](https://github.com/cosmos/cosmos-sdk/issues/18609) Fixed accounting in the block gas meter after BeginBlock and before DeliverTx, ensuring transaction processing always starts with the expected zeroed out block gas meter.
+
 ## [v0.50.2](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.50.2) - 2023-12-11
 
 ### Features
diff --git a/baseapp/abci.go b/baseapp/abci.go
index a78fc700bc14..d1ab2b53ce57 100644
--- a/baseapp/abci.go
+++ b/baseapp/abci.go
@@ -761,6 +761,10 @@ func (app *BaseApp) internalFinalizeBlock(ctx context.Context, req *abci.Request
 
 	events = append(events, beginBlock.Events...)
 
+	// Reset the gas meter so that the AnteHandlers aren't required to
+	gasMeter = app.getBlockGasMeter(app.finalizeBlockState.ctx)
+	app.finalizeBlockState.ctx = app.finalizeBlockState.ctx.WithBlockGasMeter(gasMeter)
+
 	// Iterate over all raw transactions in the proposal and attempt to execute
 	// them, gathering the execution results.
 	//
diff --git a/baseapp/baseapp_test.go b/baseapp/baseapp_test.go
index 3fe1b3463f0f..082aeacf402b 100644
--- a/baseapp/baseapp_test.go
+++ b/baseapp/baseapp_test.go
@@ -189,6 +189,40 @@ func NewBaseAppSuiteWithSnapshots(t *testing.T, cfg SnapshotsConfig, opts ...fun
 	return suite
 }
 
+func TestAnteHandlerGasMeter(t *testing.T) {
+	// run BeginBlock and assert that the gas meter passed into the first Txn is zeroed out
+	anteOpt := func(bapp *baseapp.BaseApp) {
+		bapp.SetAnteHandler(func(ctx sdk.Context, tx sdk.Tx, simulate bool) (newCtx sdk.Context, err error) {
+			gasMeter := ctx.BlockGasMeter()
+			require.NotNil(t, gasMeter)
+			require.Equal(t, storetypes.Gas(0), gasMeter.GasConsumed())
+			return ctx, nil
+		})
+	}
+	// set the beginBlocker to use some gas
+	beginBlockerOpt := func(bapp *baseapp.BaseApp) {
+		bapp.SetBeginBlocker(func(ctx sdk.Context) (sdk.BeginBlock, error) {
+			ctx.BlockGasMeter().ConsumeGas(1, "beginBlocker gas consumption")
+			return sdk.BeginBlock{}, nil
+		})
+	}
+
+	suite := NewBaseAppSuite(t, anteOpt, beginBlockerOpt)
+	_, err := suite.baseApp.InitChain(&abci.RequestInitChain{
+		ConsensusParams: &cmtproto.ConsensusParams{},
+	})
+	require.NoError(t, err)
+
+	deliverKey := []byte("deliver-key")
+	baseapptestutil.RegisterCounterServer(suite.baseApp.MsgServiceRouter(), CounterServerImpl{t, capKey1, deliverKey})
+
+	tx := newTxCounter(t, suite.txConfig, 0, 0)
+	txBytes, err := suite.txConfig.TxEncoder()(tx)
+	require.NoError(t, err)
+	_, err = suite.baseApp.FinalizeBlock(&abci.RequestFinalizeBlock{Height: 1, Txs: [][]byte{txBytes}})
+	require.NoError(t, err)
+}
+
 func TestLoadVersion(t *testing.T) {
 	logger := log.NewTestLogger(t)
 	pruningOpt := baseapp.SetPruning(pruningtypes.NewPruningOptions(pruningtypes.PruningNothing))