feat: add header hash to `Context` (backport #9390) (#9395)

* feat: add header hash to `Context` (#9390)

* baseapp, types: add header hash to

* changelog

(cherry picked from commit 151d6c5e97)

# Conflicts:
#	CHANGELOG.md

* Fix conflicts

Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>
Co-authored-by: Amaury M <1293565+amaurym@users.noreply.github.com>

CHANGELOG.md

@@ -46,6 +46,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 
 * [\#9383](https://github.com/cosmos/cosmos-sdk/pull/9383) New CLI command `query ibc-transfer escrow-address <port> <channel id>` to get the escrow address for a channel; can be used to then query balance of escrowed tokens
+* (baseapp, types) [#\9390](https://github.com/cosmos/cosmos-sdk/pull/9390) Add current block header hash to `Context`
 
 
 ## [v0.42.5](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.42.5) - 2021-05-18

baseapp/abci.go

@@ -162,7 +162,8 @@ func (app *BaseApp) BeginBlock(req abci.RequestBeginBlock) (res abci.ResponseBeg
 		// by InitChain. Context is now updated with Header information.
 		app.deliverState.ctx = app.deliverState.ctx.
 			WithBlockHeader(req.Header).
-			WithBlockHeight(req.Header.Height)
+			WithBlockHeight(req.Header.Height).
+			WithHeaderHash(req.Hash)
 	}
 
 	// add block gas meter

types/context.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/gogo/protobuf/proto"
 	abci "github.com/tendermint/tendermint/abci/types"
+	tmbytes "github.com/tendermint/tendermint/libs/bytes"
 	"github.com/tendermint/tendermint/libs/log"
 	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
 
@@ -25,6 +26,7 @@ type Context struct {
 	ctx           context.Context
 	ms            MultiStore
 	header        tmproto.Header
+	headerHash    tmbytes.HexBytes
 	chainID       string
 	txBytes       []byte
 	logger        log.Logger
@@ -63,6 +65,13 @@ func (c Context) BlockHeader() tmproto.Header {
 	return *msg
 }
 
+// HeaderHash returns a copy of the header hash obtained during abci.RequestBeginBlock
+func (c Context) HeaderHash() tmbytes.HexBytes {
+	hash := make([]byte, len(c.headerHash))
+	copy(hash, c.headerHash)
+	return hash
+}
+
 func (c Context) ConsensusParams() *abci.ConsensusParams {
 	return proto.Clone(c.consParams).(*abci.ConsensusParams)
 }
@@ -104,6 +113,15 @@ func (c Context) WithBlockHeader(header tmproto.Header) Context {
 	return c
 }
 
+// WithHeaderHash returns a Context with an updated tendermint block header hash.
+func (c Context) WithHeaderHash(hash []byte) Context {
+	temp := make([]byte, len(hash))
+	copy(temp, hash)
+
+	c.headerHash = temp
+	return c
+}
+
 // WithBlockTime returns a Context with an updated tendermint block header time in UTC time
 func (c Context) WithBlockTime(newTime time.Time) Context {
 	newHeader := c.BlockHeader()

types/context_test.go

@@ -103,6 +103,7 @@ func (s *contextTestSuite) TestContextWithCustom() {
 	meter := types.NewGasMeter(10000)
 	blockGasMeter := types.NewGasMeter(20000)
 	minGasPrices := types.DecCoins{types.NewInt64DecCoin("feetoken", 1)}
+	headerHash := []byte("headerHash")
 
 	ctx = types.NewContext(nil, header, ischeck, logger)
 	s.Require().Equal(header, ctx.BlockHeader())
@@ -114,7 +115,8 @@ func (s *contextTestSuite) TestContextWithCustom() {
 		WithVoteInfos(voteinfos).
 		WithGasMeter(meter).
 		WithMinGasPrices(minGasPrices).
-		WithBlockGasMeter(blockGasMeter)
+		WithBlockGasMeter(blockGasMeter).
+		WithHeaderHash(headerHash)
 	s.Require().Equal(height, ctx.BlockHeight())
 	s.Require().Equal(chainid, ctx.ChainID())
 	s.Require().Equal(ischeck, ctx.IsCheckTx())
@@ -124,6 +126,7 @@ func (s *contextTestSuite) TestContextWithCustom() {
 	s.Require().Equal(meter, ctx.GasMeter())
 	s.Require().Equal(minGasPrices, ctx.MinGasPrices())
 	s.Require().Equal(blockGasMeter, ctx.BlockGasMeter())
+	s.Require().Equal(headerHash, ctx.HeaderHash().Bytes())
 	s.Require().False(ctx.WithIsCheckTx(false).IsCheckTx())
 
 	// test IsReCheckTx