core, tests: get_hash fix

Make sure that we're fetching the hash from the current chain and not
the canonical chain.

2 files changed, 5 insertions, 3 deletions

diff --git a/core/vm/environment.go b/core/vm/environment.go
index ec739b26c..299d12674 100644
--- a/core/vm/environment.go
+++ b/core/vm/environment.go
@@ -39,7 +39,7 @@ type Environment interface {
 	// The block number this VM is invoken on
 	BlockNumber() *big.Int
 	// The n'th hash ago from this block number
-	GetHash(n uint64) common.Hash
+	GetHash(uint64) common.Hash
 	// The handler's address
 	Coinbase() common.Address
 	// The current time (block time)
diff --git a/core/vm_env.go b/core/vm_env.go
index 715fde52f..c8b50debc 100644
--- a/core/vm_env.go
+++ b/core/vm_env.go
@@ -59,8 +59,10 @@ func (self *VMEnv) SetDepth(i int)           { self.depth = i }
 func (self *VMEnv) VmType() vm.Type          { return self.typ }
 func (self *VMEnv) SetVmType(t vm.Type)      { self.typ = t }
 func (self *VMEnv) GetHash(n uint64) common.Hash {
-	if block := self.chain.GetBlockByNumber(n); block != nil {
-		return block.Hash()
+	for block := self.chain.GetBlock(self.header.ParentHash); block != nil; block = self.chain.GetBlock(block.ParentHash()) {
+		if block.NumberU64() == n {
+			return block.Hash()
+		}
 	}
 
 	return common.Hash{}