fix(baseapp): Reset GasMeter before deliverTX (#18714)

CHANGELOG.md

@@ -79,6 +79,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### 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.
 * (baseapp) [#18727](https://github.com/cosmos/cosmos-sdk/pull/18727) Ensure that `BaseApp.Init` firstly returns any errors from a nil commit multistore instead of panicking on nil dereferencing and before sealing the app.
 * (client) [#18622](https://github.com/cosmos/cosmos-sdk/pull/18622) Fixed a potential under/overflow from `uint64->int64` when computing gas fees as a LegacyDec.
 * (client/keys) [#18562](https://github.com/cosmos/cosmos-sdk/pull/18562) `keys delete` won't terminate when a key is not found.

baseapp/abci.go

@@ -780,6 +780,10 @@ 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.
 	//

baseapp/baseapp_test.go

@@ -192,6 +192,40 @@ 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))