fix(x/gov): set default constitution in gov migration (backport #17953) (#17983)

Co-authored-by: Julien Robert <julien@rbrt.fr>
Co-authored-by: marbar3778 <marbar3778@yahoo.com>

collections/item.go

@@ -37,7 +37,7 @@ func (i Item[V]) Set(ctx context.Context, value V) error {
 }
 
 // Has reports whether the item exists in the store or not.
-// Returns an error in case
+// Returns an error in case encoding fails.
 func (i Item[V]) Has(ctx context.Context) (bool, error) {
 	return (Map[noKey, V])(i).Has(ctx, noKey{})
 }

types/module/module.go

@@ -584,7 +584,7 @@ func (m *Manager) ExportGenesisForModules(ctx sdk.Context, cdc codec.JSONCodec,
 	for moduleName := range channels {
 		res := <-channels[moduleName]
 		if res.err != nil {
-			return nil, res.err
+			return nil, fmt.Errorf("genesis export error in %s: %w", moduleName, res.err)
 		}
 
 		genesisData[moduleName] = res.bz

x/gov/keeper/migrations.go

@@ -40,5 +40,5 @@ func (m Migrator) Migrate3to4(ctx sdk.Context) error {
 
 // Migrate4to5 migrates from version 4 to 5.
 func (m Migrator) Migrate4to5(ctx sdk.Context) error {
-	return v5.MigrateStore(ctx, m.keeper.storeService, m.keeper.cdc)
+	return v5.MigrateStore(ctx, m.keeper.storeService, m.keeper.cdc, m.keeper.Constitution)
 }

x/gov/migrations/v5/store.go

@@ -1,6 +1,7 @@
 package v5
 
 import (
+	"cosmossdk.io/collections"
 	corestoretypes "cosmossdk.io/core/store"
 
 	"github.com/cosmos/cosmos-sdk/codec"
@@ -9,11 +10,19 @@ import (
 	govv1 "github.com/cosmos/cosmos-sdk/x/gov/types/v1"
 )
 
+var (
+	// ParamsKey is the key of x/gov params
+	ParamsKey = []byte{0x30}
+	// ConstitutionKey is the key of x/gov constitution
+	ConstitutionKey = collections.NewPrefix(49)
+)
+
 // MigrateStore performs in-place store migrations from v4 (v0.47) to v5 (v0.50). The
 // migration includes:
 //
 // Addition of the new proposal expedited parameters that are set to 0 by default.
-func MigrateStore(ctx sdk.Context, storeService corestoretypes.KVStoreService, cdc codec.BinaryCodec) error {
+// Set of default chain constitution.
+func MigrateStore(ctx sdk.Context, storeService corestoretypes.KVStoreService, cdc codec.BinaryCodec, constitutionCollection collections.Item[string]) error {
 	store := storeService.OpenKVStore(ctx)
 	paramsBz, err := store.Get(v4.ParamsKey)
 	if err != nil {
@@ -38,7 +47,16 @@ func MigrateStore(ctx sdk.Context, storeService corestoretypes.KVStoreService, c
 		return err
 	}
 
-	store.Set(v4.ParamsKey, bz)
+	if err := store.Set(ParamsKey, bz); err != nil {
+		return err
+	}
+
+	// Set the default consisitution if it is not set
+	if ok, err := constitutionCollection.Has(ctx); !ok || err != nil {
+		if err := constitutionCollection.Set(ctx, "This chain has no constitution."); err != nil {
+			return err
+		}
+	}
 
 	return nil
 }

x/gov/migrations/v5/store_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"cosmossdk.io/collections"
 	storetypes "cosmossdk.io/store/types"
 
 	"github.com/cosmos/cosmos-sdk/runtime"
@@ -23,6 +24,9 @@ func TestMigrateStore(t *testing.T) {
 	govKey := storetypes.NewKVStoreKey("gov")
 	ctx := testutil.DefaultContext(govKey, storetypes.NewTransientStoreKey("transient_test"))
 	store := ctx.KVStore(govKey)
+	storeService := runtime.NewKVStoreService(govKey)
+	sb := collections.NewSchemaBuilder(storeService)
+	constitutionCollection := collections.NewItem(sb, v5.ConstitutionKey, "constitution", collections.StringValue)
 
 	var params v1.Params
 	bz := store.Get(v4.ParamsKey)
@@ -32,8 +36,7 @@ func TestMigrateStore(t *testing.T) {
 	require.Equal(t, (*time.Duration)(nil), params.ExpeditedVotingPeriod)
 
 	// Run migrations.
-	storeService := runtime.NewKVStoreService(govKey)
-	err := v5.MigrateStore(ctx, storeService, cdc)
+	err := v5.MigrateStore(ctx, storeService, cdc, constitutionCollection)
 	require.NoError(t, err)
 
 	// Check params
@@ -43,4 +46,9 @@ func TestMigrateStore(t *testing.T) {
 	require.Equal(t, v1.DefaultParams().ExpeditedMinDeposit, params.ExpeditedMinDeposit)
 	require.Equal(t, v1.DefaultParams().ExpeditedThreshold, params.ExpeditedThreshold)
 	require.Equal(t, v1.DefaultParams().ExpeditedVotingPeriod, params.ExpeditedVotingPeriod)
+
+	// Check constitution
+	result, err := constitutionCollection.Get(ctx)
+	require.NoError(t, err)
+	require.Equal(t, "This chain has no constitution.", result)
 }