fix databaseVersionKey

core/rawdb/accessors_metadata.go

@@ -30,15 +30,15 @@ import (
 // ReadDatabaseVersion reads the version number from db.
 func ReadDatabaseVersion(db ethdb.KeyValueReader) int {
 	var vsn uint
-	enc, _ := db.Get([]byte("BlockchainVersion"))
+	enc, _ := db.Get(databaseVersionKey)
 	rlp.DecodeBytes(enc, &vsn)
 	return int(vsn)
 }
 
 // WriteDatabaseVersion writes vsn as the version number to db.
 func WriteDatabaseVersion(db ethdb.KeyValueWriter, vsn int) {
 	enc, _ := rlp.EncodeToBytes(uint(vsn))
-	db.Put([]byte("BlockchainVersion"), enc)
+	db.Put(databaseVersionKey, enc)
 }
 
 // ReadChainConfig will fetch the network settings based on the given hash.

core/rawdb/schema.go

@@ -26,6 +26,9 @@ import (
 
 // The fields below define the low level database schema prefixing.
 var (
+	// databaseVersionKey tracks the current database version.
+	databaseVersionKey = []byte("DatabaseVersion")
+
 	// headHeaderKey tracks the latest known header's hash.
 	headHeaderKey = []byte("LastHeader")