Address review items:

* add comment that usedAddrBucketName was added after v1 release
* use addrHash instead of addressID for fetchAddressUsed
* define fetchAddressUsed before use
* don't bump version number
* remove unnecessary local var for used

waddrmgr/db.go

@@ -29,7 +29,7 @@ import (
 
 const (
 	// LatestMgrVersion is the most recent manager version.
-	LatestMgrVersion = 2
+	LatestMgrVersion = 1
 )
 
 var (
@@ -577,7 +577,8 @@ func deserializeAddressRow(addressID, serializedAddress []byte) (*dbAddressRow,
 // serializeAddressRow returns the serialization of the passed address row.
 func serializeAddressRow(row *dbAddressRow) []byte {
 	// The serialized address format is:
-	//   <addrType><account><addedTime><syncStatus><rawdata>
+	//   <addrType><account><addedTime><syncStatus><commentlen><comment>
+	//   <rawdata>
 	//
 	// 1 byte addrType + 4 bytes account + 8 bytes addTime + 1 byte
 	// syncStatus + 4 bytes raw data length + raw data
@@ -735,6 +736,17 @@ func serializeScriptAddress(encryptedHash, encryptedScript []byte) []byte {
 	return rawData
 }
 
+// fetchAddressUsed returns true if the provided address hash was flagged as used.
+func fetchAddressUsed(tx walletdb.Tx, addrHash [32]byte) bool {
+	bucket := tx.RootBucket().Bucket(usedAddrBucketName)
+
+	val := bucket.Get(addrHash[:])
+	if val != nil {
+		return true
+	}
+	return false
+}
+
 // fetchAddress loads address information for the provided address id from
 // the database.  The returned value is one of the address rows for the specific
 // address type.  The caller should use type assertions to ascertain the type.
@@ -752,8 +764,7 @@ func fetchAddress(tx walletdb.Tx, addressID []byte) (interface{}, error) {
 	if err != nil {
 		return nil, err
 	}
-	used := fetchAddrUsed(tx, addressID)
-	row.used = used
+	row.used = fetchAddressUsed(tx, addrHash)
 
 	switch row.addrType {
 	case adtChain:
@@ -785,18 +796,6 @@ func markAddressUsed(tx walletdb.Tx, addressID []byte) error {
 	return nil
 }
 
-// fetchAddrUsed returns true if the provided address id was flagged as used.
-func fetchAddrUsed(tx walletdb.Tx, addressID []byte) bool {
-	bucket := tx.RootBucket().Bucket(usedAddrBucketName)
-
-	addrHash := fastsha256.Sum256(addressID)
-	val := bucket.Get(addrHash[:])
-	if val != nil {
-		return true
-	}
-	return false
-}
-
 // putAddress stores the provided address information to the database.  This
 // is used a common base for storing the various address types.
 func putAddress(tx walletdb.Tx, addressID []byte, row *dbAddressRow) error {
@@ -1277,6 +1276,7 @@ func createManagerNS(namespace walletdb.Namespace) error {
 			return managerError(ErrDatabase, str, err)
 		}
 
+		// usedAddrBucketName bucket was added after manager version 1 release
 		_, err = rootBucket.CreateBucketIfNotExists(usedAddrBucketName)
 		if err != nil {
 			str := "failed to create used addresses bucket"
@@ -1364,35 +1364,3 @@ func upgradeManager(namespace walletdb.Namespace) error {
 
 	return nil
 }
-
-// upgradeVersion1to2 upgrades the database from version 1 to version 2
-// 'usedAddrBucketName' a bucket for storing addrs flagged as marked is initialized
-// and it will be updated on the next rescan
-func upgradeVersion1to2(namespace walletdb.Namespace) error {
-	err := namespace.Update(func(tx walletdb.Tx) error {
-		rootBucket := tx.RootBucket()
-		mainBucket := tx.RootBucket().Bucket(mainBucketName)
-
-		_, err := rootBucket.CreateBucketIfNotExists(usedAddrBucketName)
-		if err != nil {
-			str := "failed to create used addresses bucket"
-			return managerError(ErrDatabase, str, err)
-		}
-
-		var version uint32
-		var buf [4]byte
-		version = LatestMgrVersion
-		binary.LittleEndian.PutUint32(buf[:], version)
-		err = mainBucket.Put(mgrVersionName, buf[:])
-		if err != nil {
-			str := "failed to store latest database version"
-			return managerError(ErrDatabase, str, err)
-		}
-		return nil
-	})
-	if err != nil {
-		str := "failed to upgrade version 1 to version 2"
-		return managerError(ErrDatabase, str, err)
-	}
-	return nil
-}