fix: populate ctx.ConsensusParams for begin blockers (cosmos#10725)

Closes: cosmos#10724



## Description



---

### Author Checklist

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please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

CHANGELOG.md

@@ -189,6 +189,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/bank) [\#9890] (https://github.com/cosmos/cosmos-sdk/pull/9890) Remove duplicate denom from denom metadata key.
 * (x/upgrade) [\#10189](https://github.com/cosmos/cosmos-sdk/issues/10189) Removed potential sources of non-determinism in upgrades
 * [\#10393](https://github.com/cosmos/cosmos-sdk/pull/10422) Add `MinCommissionRate` param to `x/staking` module.
+* [#10725](https://github.com/cosmos/cosmos-sdk/pull/10725) populate `ctx.ConsensusParams` for begin/end blockers.
 
  ### Deprecated
 

baseapp/abci.go

@@ -174,7 +174,8 @@ func (app *BaseApp) BeginBlock(req abci.RequestBeginBlock) (res abci.ResponseBeg
 
 	app.deliverState.ctx = app.deliverState.ctx.
 		WithBlockGasMeter(gasMeter).
-		WithHeaderHash(req.Hash)
+		WithHeaderHash(req.Hash).
+		WithConsensusParams(app.GetConsensusParams(app.deliverState.ctx))
 
 	// we also set block gas meter to checkState in case the application needs to
 	// verify gas consumption during (Re)CheckTx

baseapp/baseapp_test.go

@@ -2,6 +2,7 @@ package baseapp_test
 
 import (
 	"bytes"
+	"context"
 	"encoding/binary"
 	"encoding/json"
 	"fmt"
@@ -239,6 +240,51 @@ func TestMountStores(t *testing.T) {
 	require.NotNil(t, store2)
 }
 
+type MockTxHandler struct {
+	T *testing.T
+}
+
+func (th MockTxHandler) CheckTx(goCtx context.Context, req tx.Request, checkReq tx.RequestCheckTx) (tx.Response, tx.ResponseCheckTx, error) {
+	ctx := sdk.UnwrapSDKContext(goCtx)
+	require.NotNil(th.T, ctx.ConsensusParams())
+	return tx.Response{}, tx.ResponseCheckTx{}, nil
+}
+
+func (th MockTxHandler) DeliverTx(goCtx context.Context, req tx.Request) (tx.Response, error) {
+	ctx := sdk.UnwrapSDKContext(goCtx)
+	require.NotNil(th.T, ctx.ConsensusParams())
+	return tx.Response{}, nil
+}
+
+func (th MockTxHandler) SimulateTx(goCtx context.Context, req tx.Request) (tx.Response, error) {
+	ctx := sdk.UnwrapSDKContext(goCtx)
+	require.NotNil(th.T, ctx.ConsensusParams())
+	return tx.Response{}, nil
+}
+
+func TestConsensusParamsNotNil(t *testing.T) {
+	app := setupBaseApp(t, func(app *baseapp.BaseApp) {
+		app.SetBeginBlocker(func(ctx sdk.Context, req abci.RequestBeginBlock) abci.ResponseBeginBlock {
+			require.NotNil(t, ctx.ConsensusParams())
+			return abci.ResponseBeginBlock{}
+		})
+	}, func(app *baseapp.BaseApp) {
+		app.SetEndBlocker(func(ctx sdk.Context, req abci.RequestEndBlock) abci.ResponseEndBlock {
+			require.NotNil(t, ctx.ConsensusParams())
+			return abci.ResponseEndBlock{}
+		})
+	}, func(app *baseapp.BaseApp) {
+		app.SetTxHandler(MockTxHandler{T: t})
+	})
+
+	header := tmproto.Header{Height: 1}
+	app.BeginBlock(abci.RequestBeginBlock{Header: header})
+	app.EndBlock(abci.RequestEndBlock{Height: header.Height})
+	app.CheckTx(abci.RequestCheckTx{})
+	app.DeliverTx(abci.RequestDeliverTx{})
+	app.Simulate([]byte{})
+}
+
 // Test that we can make commits and then reload old versions.
 // Test that LoadLatestVersion actually does.
 func TestLoadVersion(t *testing.T) {