From 3f394a1af5fbe7b7e2374d7de69d17eb2cd3a872 Mon Sep 17 00:00:00 2001
From: Cha Minkyoo <minkyoo.cha@medibloc.org>
Date: Thu, 28 Feb 2019 11:20:40 +0900
Subject: [PATCH] Fix missing error check in voted list conversion

---
 common/trie/iterator.go   | 20 ++++++++++++++++++++
 core/state/account.go     |  4 ++--
 core/transaction/stake.go | 10 ++++++++--
 rpc/mapper.go             |  7 ++++++-
 4 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/common/trie/iterator.go b/common/trie/iterator.go
index aeee9c20..71871c00 100644
--- a/common/trie/iterator.go
+++ b/common/trie/iterator.go
@@ -122,6 +122,26 @@ func (t *Trie) getSubTrieWithMaxCommonPrefix(prefix []byte) ([]byte, []byte, err
 	return curRootHash, route, nil
 }
 
+// Keys returns all keys starting with the given prefix.
+func (t *Trie) Keys(prefix []byte) ([][]byte, error) {
+	keys := make([][]byte, 0)
+	iter, err := t.Iterator(prefix)
+	if err != nil {
+		return nil, err
+	}
+	for {
+		exist, err := iter.Next()
+		if err != nil {
+			return nil, err
+		}
+		if !exist {
+			break
+		}
+		keys = append(keys, iter.Key())
+	}
+	return keys, nil
+}
+
 func (it *Iterator) push(node *node, pos int, route []byte) {
 	it.stack = append(it.stack, &IteratorState{node, pos, route})
 }
diff --git a/core/state/account.go b/core/state/account.go
index 3fff1bf8..d403d216 100644
--- a/core/state/account.go
+++ b/core/state/account.go
@@ -173,8 +173,8 @@ func (acc *Account) ToBytes() ([]byte, error) {
 }
 
 // VotedSlice returns slice converted from Voted trie
-func (acc *Account) VotedSlice() [][]byte {
-	return KeyTrieToSlice(acc.Voted)
+func (acc *Account) VotedSlice() ([][]byte, error) {
+	return acc.Voted.Keys(nil)
 }
 
 // GetData returns value in account's data trie
diff --git a/core/transaction/stake.go b/core/transaction/stake.go
index 90e6919b..6e609441 100644
--- a/core/transaction/stake.go
+++ b/core/transaction/stake.go
@@ -71,7 +71,10 @@ func (tx *StakeTx) Execute(b *core.Block) error {
 		return err
 	}
 
-	voted := user.VotedSlice()
+	voted, err := user.VotedSlice()
+	if err != nil {
+		return err
+	}
 
 	// Add user's stake to candidates' votePower
 	for _, v := range voted {
@@ -162,7 +165,10 @@ func (tx *UnstakeTx) Execute(b *core.Block) error {
 		account.Points = account.Staking.DeepCopy()
 	}
 
-	voted := account.VotedSlice()
+	voted, err := account.VotedSlice()
+	if err != nil {
+		return err
+	}
 
 	err = b.State().PutAccount(account)
 	if err != nil {
diff --git a/rpc/mapper.go b/rpc/mapper.go
index 62cb6a80..a5b42177 100644
--- a/rpc/mapper.go
+++ b/rpc/mapper.go
@@ -35,12 +35,17 @@ func coreAccount2rpcAccount(account *coreState.Account, curTs int64, address str
 	if err != nil {
 		return nil, err
 	}
+	votedSlice, err := account.VotedSlice()
+	if err != nil {
+		return nil, err
+	}
+	voted := byteutils.BytesSlice2HexSlice(votedSlice)
 	return &rpcpb.Account{
 		Address:     address,
 		Balance:     account.Balance.String(),
 		Nonce:       account.Nonce,
 		Staking:     account.Staking.String(),
-		Voted:       byteutils.BytesSlice2HexSlice(account.VotedSlice()),
+		Voted:       voted,
 		Points:      account.Points.String(),
 		Unstaking:   account.Unstaking.String(),
 		Alias:       pbAlias.AliasName,