fix: invalid return value from keeper GetLastCompleteUpgrade

x/upgrade/keeper/keeper.go

@@ -235,12 +235,32 @@ func (k Keeper) GetUpgradedConsensusState(ctx sdk.Context, lastHeight int64) ([]
 	return bz, true
 }
 
+type upgrade struct {
+	Name        string
+	BlockHeight int64
+}
+
 // GetLastCompletedUpgrade returns the last applied upgrade name and height.
 func (k Keeper) GetLastCompletedUpgrade(ctx sdk.Context) (string, int64) {
 	iter := sdk.KVStoreReversePrefixIterator(ctx.KVStore(k.storeKey), []byte{types.DoneByte})
 	defer iter.Close()
-	if iter.Valid() {
-		return parseDoneKey(iter.Key()), int64(binary.BigEndian.Uint64(iter.Value()))
+
+	upgrades := []upgrade{}
+	for iter.Valid() {
+		name := parseDoneKey(iter.Key())
+		value := int64(binary.BigEndian.Uint64(iter.Value()))
+		upgrades = append(upgrades, struct {
+			Name        string
+			BlockHeight int64
+		}{Name: name, BlockHeight: value})
+		iter.Next()
+	}
+	sort.SliceStable(upgrades, func(i, j int) bool {
+		return upgrades[i].BlockHeight > upgrades[j].BlockHeight
+	})
+
+	if len(upgrades) > 0 {
+		return upgrades[0].Name, upgrades[0].BlockHeight
 	}
 
 	return "", 0

x/upgrade/keeper/keeper_test.go

@@ -278,6 +278,40 @@ func (s *KeeperTestSuite) TestLastCompletedUpgrade() {
 	require.Equal(int64(15), height)
 }
 
+func (s *KeeperTestSuite) TestLastCompletedUpgradeOrdering() {
+	keeper := s.app.UpgradeKeeper
+	require := s.Require()
+
+	// apply first upgrade
+	keeper.SetUpgradeHandler("test-v0.9", func(_ sdk.Context, _ types.Plan, vm module.VersionMap) (module.VersionMap, error) {
+		return vm, nil
+	})
+
+	keeper.ApplyUpgrade(s.ctx, types.Plan{
+		Name:   "test-v0.9",
+		Height: 10,
+	})
+
+	name, height := keeper.GetLastCompletedUpgrade(s.ctx)
+	require.Equal("test-v0.9", name)
+	require.Equal(int64(10), height)
+
+	// apply second upgrade
+	keeper.SetUpgradeHandler("test-v0.10", func(_ sdk.Context, _ types.Plan, vm module.VersionMap) (module.VersionMap, error) {
+		return vm, nil
+	})
+
+	newCtx := s.ctx.WithBlockHeight(15)
+	keeper.ApplyUpgrade(newCtx, types.Plan{
+		Name:   "test-v0.10",
+		Height: 15,
+	})
+
+	name, height = keeper.GetLastCompletedUpgrade(newCtx)
+	require.Equal("test-v0.10", name)
+	require.Equal(int64(15), height)
+}
+
 func TestKeeperTestSuite(t *testing.T) {
 	suite.Run(t, new(KeeperTestSuite))
 }