blockchain: Delete block headers from old block index bucket.

As part of the migration to the new block index bucket, also delete
the redundant data from the old bucket.

blockchain/chainio.go

@@ -1192,7 +1192,7 @@ func (b *BlockChain) initChainState() error {
 		// number of nodes are already known, perform a single alloc
 		// for them versus a whole bunch of little ones to reduce
 		// pressure on the GC.
-		log.Infof("Loading block index.  This might take a while...")
+		log.Infof("Loading block index...")
 
 		blockIndexBucket := dbTx.Metadata().Bucket(blockIndexBucketName)
 

blockchain/upgrade.go

@@ -72,8 +72,16 @@ func migrateBlockIndex(db database.DB) error {
 					"stored block %s", hash)
 			}
 
+			// Write header to v2 bucket
 			key := blockIndexKey(&hash, height)
-			return v2BlockIdxBucket.Put(key, headerBytes)
+			err := v2BlockIdxBucket.Put(key, headerBytes)
+			if err != nil {
+				return err
+			}
+
+			// Delete header from v1 bucket
+			truncatedRow := blockRow[0:blockHdrOffset:blockHdrOffset]
+			return v1BlockIdxBucket.Put(hashBytes, truncatedRow)
 		})
 	})
 	if err != nil {