From b8ca0a830e89d4d7c4314c13bcbc2629992f43d9 Mon Sep 17 00:00:00 2001
From: Jeffrey Wilcke <geffobscura@gmail.com>
Date: Thu, 13 Aug 2015 20:44:03 +0200
Subject: [PATCH] eth, trie: removed key prefixing from state entries & merge
 db fix

Fixed database merge strategy to use the correct database. Due to a copy
paste fail when doing type evaluation the same database was being
iterated (chain), all others were ignored.

Removed state prefixing because {H(code): code} is stored in the same
database as the rest of the state.
---
 eth/backend.go | 34 +++++++++++++++++++---------------
 trie/cache.go  |  4 ----
 trie/trie.go   |  2 --
 3 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/eth/backend.go b/eth/backend.go
index c9b71803f..953a150ad 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -45,7 +45,6 @@ import (
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/p2p/nat"
-	"github.com/ethereum/go-ethereum/trie"
 	"github.com/ethereum/go-ethereum/whisper"
 )
 
@@ -738,48 +737,53 @@ func mergeDatabases(datadir string, newdb func(path string) (common.Database, er
 	}
 	defer database.Close()
 
-	glog.Infoln("Merging blockchain database...")
+	// Migrate blocks
 	chainDb, err := newdb(chainPath)
 	if err != nil {
 		return fmt.Errorf("state db err: %v", err)
 	}
 	defer chainDb.Close()
 
-	if db, ok := chainDb.(*ethdb.LDBDatabase); ok {
-		it := db.NewIterator()
+	if chain, ok := chainDb.(*ethdb.LDBDatabase); ok {
+		glog.Infoln("Merging blockchain database...")
+		it := chain.NewIterator()
 		for it.Next() {
 			database.Put(it.Key(), it.Value())
 		}
+		it.Release()
 	}
 
-	glog.Infoln("Merging state database...")
-	state := filepath.Join(datadir, "state")
-	stateDb, err := newdb(state)
+	// Migrate state
+	stateDb, err := newdb(filepath.Join(datadir, "state"))
 	if err != nil {
 		return fmt.Errorf("state db err: %v", err)
 	}
 	defer stateDb.Close()
 
-	if db, ok := chainDb.(*ethdb.LDBDatabase); ok {
-		it := db.NewIterator()
+	if state, ok := stateDb.(*ethdb.LDBDatabase); ok {
+		glog.Infoln("Merging state database...")
+		it := state.NewIterator()
 		for it.Next() {
-			database.Put(append(trie.StatePre, it.Key()...), it.Value())
+			database.Put(it.Key(), it.Value())
 		}
+		it.Release()
 	}
 
-	glog.Infoln("Merging transaction database...")
-	extra := filepath.Join(datadir, "extra")
-	extraDb, err := newdb(extra)
+	// Migrate transaction / receipts
+	extraDb, err := newdb(filepath.Join(datadir, "extra"))
 	if err != nil {
 		return fmt.Errorf("state db err: %v", err)
 	}
 	defer extraDb.Close()
 
-	if db, ok := chainDb.(*ethdb.LDBDatabase); ok {
-		it := db.NewIterator()
+	if extra, ok := extraDb.(*ethdb.LDBDatabase); ok {
+		glog.Infoln("Merging transaction database...")
+
+		it := extra.NewIterator()
 		for it.Next() {
 			database.Put(it.Key(), it.Value())
 		}
+		it.Release()
 	}
 
 	return nil
diff --git a/trie/cache.go b/trie/cache.go
index 99d8033a6..e475fc861 100644
--- a/trie/cache.go
+++ b/trie/cache.go
@@ -38,8 +38,6 @@ func NewCache(backend Backend) *Cache {
 }
 
 func (self *Cache) Get(key []byte) []byte {
-	key = append(StatePre, key...)
-
 	data := self.store[string(key)]
 	if data == nil {
 		data, _ = self.backend.Get(key)
@@ -49,8 +47,6 @@ func (self *Cache) Get(key []byte) []byte {
 }
 
 func (self *Cache) Put(key []byte, data []byte) {
-	key = append(StatePre, key...)
-
 	self.batch.Put(key, data)
 	self.store[string(key)] = data
 }
diff --git a/trie/trie.go b/trie/trie.go
index 2970bc185..abf48a850 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -27,8 +27,6 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
-var StatePre = []byte("state-")
-
 func ParanoiaCheck(t1 *Trie, backend Backend) (bool, *Trie) {
 	t2 := New(nil, backend)