fix: address generation of the empty coins in x/foundation (backport #…

…952) (#1072)

* Revert "fix: revert #952 (#984)"

This reverts commit ea50f75.

* Update CHANGELOG.md

CHANGELOG.md

@@ -44,6 +44,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ### Improvements
 * (third_party/proto) [\#1037](https://github.com/Finschia/finschia-sdk/pull/1037) change the proof.proto path to third_party/proto/confio
 * (ostracon) [\#1057](https://github.com/Finschia/finschia-sdk/pull/1057) Bump up Ostracon from to v1.1.1
+* (x/foundation) [\#1072](https://github.com/Finschia/finschia-sdk/pull/1072) Address generation of the empty coins in x/foundation (backport #952)
 
 ### Bug Fixes
 * (ledger) [\#1040](https://github.com/Finschia/finschia-sdk/pull/1040) fix a bug(unable to connect nano S plus ledger on ubuntu)

client/grpc/tmservice/service_test.go

@@ -152,7 +152,7 @@ func (s IntegrationTestSuite) TestQueryBlockResultsByHeight() {
 	s.Require().Equal(0, len(txResult))
 
 	beginBlock := blockResultsRes.GetResBeginBlock()
-	s.Require().Equal(11, len(beginBlock.Events)) // coinbase event (6) + transfer mintModule to feeCollectorName(5)
+	s.Require().Equal(7, len(beginBlock.Events)) // coinbase event (6) + transfer mintModule to feeCollectorName(5) - foundation abci (4)
 
 	endBlock := blockResultsRes.GetResEndBlock()
 	s.Require().Equal(0, len(endBlock.Events))

x/foundation/keeper/internal/treasury.go

@@ -9,11 +9,17 @@ import (
 func (k Keeper) CollectFoundationTax(ctx sdk.Context) error {
 	feeCollector := k.authKeeper.GetModuleAccount(ctx, k.feeCollectorName).GetAddress()
 	feesCollectedInt := k.bankKeeper.GetAllBalances(ctx, feeCollector)
+	if feesCollectedInt.Empty() {
+		return nil
+	}
 	feesCollected := sdk.NewDecCoinsFromCoins(feesCollectedInt...)
 
 	// calculate the tax
 	taxRatio := k.GetFoundationTax(ctx)
 	tax, _ := feesCollected.MulDecTruncate(taxRatio).TruncateDecimal()
+	if tax.Empty() {
+		return nil
+	}
 
 	// collect the tax
 	if err := k.FundTreasury(ctx, feeCollector, tax); err != nil {