From 665bb43a4c9e97d6f23de02575b92156881a2db8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felf=C3=B6ldi=20Zsolt?= <zsfelfoldi@gmail.com>
Date: Mon, 28 Nov 2016 11:31:15 +0100
Subject: [PATCH] light: implemented VMState.Empty() (#3357)

---
 light/state_object.go | 9 +++++++--
 light/vm_env.go       | 7 +++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/light/state_object.go b/light/state_object.go
index 61c3888fe..6161d2dfb 100644
--- a/light/state_object.go
+++ b/light/state_object.go
@@ -201,14 +201,19 @@ func (self *StateObject) Copy() *StateObject {
 // Attribute accessors
 //
 
+// empty returns whether the account is considered empty.
+func (self *StateObject) empty() bool {
+	return self.nonce == 0 && self.balance.BitLen() == 0 && bytes.Equal(self.codeHash, emptyCodeHash)
+}
+
 // Balance returns the account balance
 func (self *StateObject) Balance() *big.Int {
 	return self.balance
 }
 
 // Address returns the address of the contract/account
-func (c *StateObject) Address() common.Address {
-	return c.address
+func (self *StateObject) Address() common.Address {
+	return self.address
 }
 
 // Code returns the contract code
diff --git a/light/vm_env.go b/light/vm_env.go
index 5d330b072..d4d7bcce7 100644
--- a/light/vm_env.go
+++ b/light/vm_env.go
@@ -263,6 +263,13 @@ func (s *VMState) Exist(addr common.Address) bool {
 	return res
 }
 
+// Empty returns true if the account at the given address is considered empty
+func (s *VMState) Empty(addr common.Address) bool {
+	so, err := s.state.GetStateObject(s.ctx, addr)
+	s.errHandler(err)
+	return so == nil || so.empty()
+}
+
 // HasSuicided returns true if the given account has been marked for deletion
 // or false if the account does not exist
 func (s *VMState) HasSuicided(addr common.Address) bool {