[Bugfix] sort migrated map array to get deterministic result (#536)

* sort migrated map items to get deterministic result

* add changelog

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.5.1
+
+### Bug Fixes
+- [\#536](https://github.com/terra-money/core/pull/536) Sort migrated map array with key to generate deterministic result
+
 ## 0.5.0
 
 ### Improvements

x/oracle/legacy/v05/migrate.go

@@ -1,6 +1,8 @@
 package v05
 
 import (
+	"sort"
+
 	v04oracle "github.com/terra-money/core/x/oracle/legacy/v04"
 	v05oracle "github.com/terra-money/core/x/oracle/types"
 )
@@ -45,6 +47,8 @@ func Migrate(
 		}
 	}
 
+	// Note that the four following `for` loop over a map's keys, so are not
+	// deterministic.
 	i := 0
 	missCounters := make([]v05oracle.MissCounter, len(oracleGenState.MissCounters))
 	for validatorAddress, missCounter := range oracleGenState.MissCounters {
@@ -57,22 +61,22 @@ func Migrate(
 	}
 
 	i = 0
-	exchangeRates := make([]v05oracle.ExchangeRateTuple, len(oracleGenState.ExchangeRates))
-	for denom, exchangeRate := range oracleGenState.ExchangeRates {
-		exchangeRates[i] = v05oracle.ExchangeRateTuple{
-			Denom:        denom,
-			ExchangeRate: exchangeRate,
+	feederDelegations := make([]v05oracle.FeederDelegation, len(oracleGenState.FeederDelegations))
+	for validatorAddress, feederAddress := range oracleGenState.FeederDelegations {
+		feederDelegations[i] = v05oracle.FeederDelegation{
+			ValidatorAddress: validatorAddress,
+			FeederAddress:    feederAddress.String(),
 		}
 
 		i++
 	}
 
 	i = 0
-	feederDelegations := make([]v05oracle.FeederDelegation, len(oracleGenState.FeederDelegations))
-	for validatorAddress, feederAddress := range oracleGenState.FeederDelegations {
-		feederDelegations[i] = v05oracle.FeederDelegation{
-			ValidatorAddress: validatorAddress,
-			FeederAddress:    feederAddress.String(),
+	exchangeRates := make([]v05oracle.ExchangeRateTuple, len(oracleGenState.ExchangeRates))
+	for denom, exchangeRate := range oracleGenState.ExchangeRates {
+		exchangeRates[i] = v05oracle.ExchangeRateTuple{
+			Denom:        denom,
+			ExchangeRate: exchangeRate,
 		}
 
 		i++
@@ -89,6 +93,14 @@ func Migrate(
 		i++
 	}
 
+	// We sort these four arrays by validator address and denom, so that we get determinstic states.
+	sort.Slice(missCounters, func(i, j int) bool { return missCounters[i].ValidatorAddress < missCounters[j].ValidatorAddress })
+	sort.Slice(feederDelegations, func(i, j int) bool {
+		return feederDelegations[i].ValidatorAddress < feederDelegations[j].ValidatorAddress
+	})
+	sort.Slice(exchangeRates, func(i, j int) bool { return exchangeRates[i].Denom < exchangeRates[j].Denom })
+	sort.Slice(tobinTaxes, func(i, j int) bool { return tobinTaxes[i].Denom < tobinTaxes[j].Denom })
+
 	return &v05oracle.GenesisState{
 		AggregateExchangeRatePrevotes: aggregateExchangeRatePrevote,
 		AggregateExchangeRateVotes:    aggregateExchangeRateVote,

x/treasury/legacy/v05/migrate.go

@@ -1,6 +1,8 @@
 package v05
 
 import (
+	"sort"
+
 	v04treasury "github.com/terra-money/core/x/treasury/legacy/v04"
 	v05treasury "github.com/terra-money/core/x/treasury/types"
 
@@ -17,6 +19,8 @@ import (
 func Migrate(
 	treasuryGenState v04treasury.GenesisState,
 ) *v05treasury.GenesisState {
+	// Note that the following `for` loop over a map's keys, so are not
+	// deterministic.
 	i := 0
 	taxCaps := make([]v05treasury.TaxCap, len(treasuryGenState.TaxCaps))
 	for denom, cap := range treasuryGenState.TaxCaps {
@@ -28,6 +32,9 @@ func Migrate(
 		i++
 	}
 
+	// We sort this array by denom, so that we get determinstic states.
+	sort.Slice(taxCaps, func(i, j int) bool { return taxCaps[i].Denom < taxCaps[j].Denom })
+
 	// Remove cumulative height dependencies
 	cumulativeEpochs := int(treasuryGenState.CumulativeHeight / int64(v04treasury.BlocksPerWeek))
 	epochStates := make([]v05treasury.EpochState, len(treasuryGenState.TRs)-cumulativeEpochs)