Merge PR #5497: ensure non-nil gentxs

CHANGELOG.md

@@ -65,6 +65,7 @@ is the latest height, we'll use the store's `lastCommitInfo`. Otherwise, we fetc
 * (x/bank) [\#5531](https://github.com/cosmos/cosmos-sdk/issues/5531) Added missing amount event to MsgMultiSend, emitted for each output.
 * (client) [\#5618](https://github.com/cosmos/cosmos-sdk/pull/5618) Fix crash on the client when the verifier is not set. 
 * (x/distribution) [\#5620](https://github.com/cosmos/cosmos-sdk/pull/5620) Fix nil pointer deref in distribution tax/rewward validation helpers.
+* (genesis) [\#5086](https://github.com/cosmos/cosmos-sdk/issues/5086) Ensure `gentxs` are always an empty array instead of `nil`
 
 ### State Machine Breaking
 

x/genutil/types/genesis_state.go

@@ -20,6 +20,10 @@ type GenesisState struct {
 
 // NewGenesisState creates a new GenesisState object
 func NewGenesisState(genTxs []json.RawMessage) GenesisState {
+	// Ensure genTxs is never nil, https://github.com/cosmos/cosmos-sdk/issues/5086
+	if len(genTxs) == 0 {
+		genTxs = make([]json.RawMessage, 0)
+	}
 	return GenesisState{
 		GenTxs: genTxs,
 	}

x/genutil/types/genesis_state_test.go

@@ -1,8 +1,10 @@
 package types
 
 import (
+	"encoding/json"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/tendermint/tendermint/crypto/ed25519"
 
@@ -16,6 +18,18 @@ var (
 	pk2 = ed25519.GenPrivKey().PubKey()
 )
 
+func TestNetGenesisState(t *testing.T) {
+	gen := NewGenesisState(nil)
+	assert.NotNil(t, gen.GenTxs) // https://github.com/cosmos/cosmos-sdk/issues/5086
+
+	gen = NewGenesisState(
+		[]json.RawMessage{
+			[]byte(`{"foo":"bar"}`),
+		},
+	)
+	assert.Equal(t, string(gen.GenTxs[0]), `{"foo":"bar"}`)
+}
+
 func TestValidateGenesisMultipleMessages(t *testing.T) {
 
 	desc := stakingtypes.NewDescription("testname", "", "", "", "")