evm: ForEachStorage semantic not compatible with go-ethereum (#798)

* Problem: ForEachStorage sematic not compatible with go-ethereum

Solution:
- reversed the semantic of return value of the callback function.

* changelog

Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com>

x/evm/keeper/keeper.go

@@ -295,7 +295,7 @@ func (k Keeper) GetAccountStorage(ctx sdk.Context, address common.Address) (type
 
 	err := k.ForEachStorage(address, func(key, value common.Hash) bool {
 		storage = append(storage, types.NewState(key, value))
-		return false
+		return true
 	})
 	if err != nil {
 		return types.Storage{}, err
@@ -317,7 +317,7 @@ func (k Keeper) DeleteState(addr common.Address, key common.Hash) {
 func (k Keeper) DeleteAccountStorage(addr common.Address) {
 	_ = k.ForEachStorage(addr, func(key, _ common.Hash) bool {
 		k.DeleteState(addr, key)
-		return false
+		return true
 	})
 }
 

x/evm/keeper/statedb.go

@@ -795,6 +795,7 @@ func (k *Keeper) AddPreimage(_ common.Hash, _ []byte) {}
 
 // ForEachStorage uses the store iterator to iterate over all the state keys and perform a callback
 // function on each of them.
+// The callback should return `true` to continue, return `false` to break early.
 func (k *Keeper) ForEachStorage(addr common.Address, cb func(key, value common.Hash) bool) error {
 	if k.HasStateError() {
 		return k.stateErr
@@ -814,7 +815,7 @@ func (k *Keeper) ForEachStorage(addr common.Address, cb func(key, value common.H
 		value := common.BytesToHash(iterator.Value())
 
 		// check if iteration stops
-		if cb(key, value) {
+		if !cb(key, value) {
 			return nil
 		}
 	}

x/evm/keeper/statedb_test.go

@@ -747,7 +747,7 @@ func (suite *KeeperTestSuite) TestForEachStorage() {
 			},
 			func(key, value common.Hash) bool {
 				storage = append(storage, types.NewState(key, value))
-				return false
+				return true
 			},
 			[]common.Hash{
 				common.BytesToHash([]byte("value0")),
@@ -766,9 +766,9 @@ func (suite *KeeperTestSuite) TestForEachStorage() {
 			func(key, value common.Hash) bool {
 				if value == common.BytesToHash([]byte("filtervalue")) {
 					storage = append(storage, types.NewState(key, value))
-					return true
+					return false
 				}
-				return false
+				return true
 			},
 			[]common.Hash{
 				common.BytesToHash([]byte("filtervalue")),