revert: last block height == 0 check (#3225)

Closes #2271

app/prepare_proposal.go

@@ -47,25 +47,7 @@ func (app *App) PrepareProposal(req abci.RequestPrepareProposal) abci.ResponsePr
 		app.ParamsKeeper,
 		app.MsgGateKeeper,
 	)
-
-	var txs [][]byte
-	// This if statement verifies whether the preparation of the proposal
-	// pertains to the first block. If it does, the block is constructed using
-	// an empty set of transactions. However, even without this validation,
-	// the initial block is anticipated to be devoid of transactions, as
-	// established by the findings presented in
-	// https://github.com/celestiaorg/celestia-app/issues/1899;
-	// The inclusion of this check is out of an abundance of caution.
-	// The rationale behind having an empty first block revolves around the fact
-	// that no transactions can enter the mempool since no committed state exists
-	// until after the first block is committed (at which point the Genesis state
-	// gets committed too). Consequently, the prepare proposal request for the
-	// first block is expected to contain no transaction, so is the first block.
-	if app.LastBlockHeight() == 0 {
-		txs = make([][]byte, 0)
-	} else {
-		txs = FilterTxs(app.Logger(), sdkCtx, handler, app.txConfig, req.BlockData.Txs)
-	}
+	txs := FilterTxs(app.Logger(), sdkCtx, handler, app.txConfig, req.BlockData.Txs)
 
 	// build the square from the set of valid and prioritised transactions.
 	// The txs returned are the ones used in the square and block

app/test/prepare_proposal_test.go

@@ -217,25 +217,3 @@ func queryAccountInfo(capp *app.App, accs []string, kr keyring.Keyring) []blobfa
 	}
 	return infos
 }
-
-func TestPrepareProposalZeroTxsInFirstBlock(t *testing.T) {
-	accounts := testfactory.GenerateAccounts(6)
-	testApp, _, kr := testutil.NewTestAppWithGenesisSet(app.DefaultConsensusParams(), accounts...)
-	require.Equal(t, int64(0), testApp.LastBlockHeight())
-	encCfg := encoding.MakeConfig(app.ModuleEncodingRegisters...)
-	sendTxs := coretypes.Txs{testutil.SendTxWithManualSequence(
-		t,
-		encCfg.TxConfig,
-		kr,
-		accounts[0],
-		accounts[1],
-		1000,
-		testutil.ChainID,
-		1,
-		1,
-	)}.ToSliceOfBytes()
-	resp := testApp.PrepareProposal(abci.RequestPrepareProposal{
-		BlockData: &tmproto.Data{Txs: sendTxs},
-	})
-	require.Len(t, resp.BlockData.Txs, 0)
-}