fix(baseapp): return events from preblocker in FinalizeBlockResponse (backport #21159) (#21161)

Co-authored-by: Facundo Medica <14063057+facundomedica@users.noreply.github.com>

Author: mergify[bot]

CHANGELOG.md

@@ -108,6 +108,7 @@ Every module contains its own CHANGELOG.md. Please refer to the module you are i
 
 ### Bug Fixes
 
+* (baseapp) [#21159](https://github.com/cosmos/cosmos-sdk/pull/21159) Return PreBlocker events in FinalizeBlockResponse.
 * (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

@@ -789,6 +789,7 @@ func (app *BaseApp) internalFinalizeBlock(ctx context.Context, req *abci.Finaliz
 	if err := app.preBlock(req); err != nil {
 		return nil, err
 	}
+	events = append(events, app.finalizeBlockState.ctx.EventManager().ABCIEvents()...)
 
 	beginBlock, err := app.beginBlock(req)
 	if err != nil {

baseapp/abci_test.go

@@ -2062,13 +2062,16 @@ func TestBaseApp_PreBlocker(t *testing.T) {
 	wasHookCalled := false
 	app.SetPreBlocker(func(ctx sdk.Context, req *abci.FinalizeBlockRequest) error {
 		wasHookCalled = true
+		ctx.EventManager().EmitEvent(sdk.NewEvent("preblockertest", sdk.NewAttribute("height", fmt.Sprintf("%d", req.Height))))
 		return nil
 	})
 	app.Seal()
 
-	_, err = app.FinalizeBlock(&abci.FinalizeBlockRequest{Height: 1})
+	res, err := app.FinalizeBlock(&abci.FinalizeBlockRequest{Height: 1})
 	require.NoError(t, err)
 	require.Equal(t, true, wasHookCalled)
+	require.Len(t, res.Events, 1)
+	require.Equal(t, "preblockertest", res.Events[0].Type)
 
 	// Now try erroring
 	app = baseapp.NewBaseApp(name, logger, db, nil)