channeldb: replace opening height will short chan ID in OpenChannel

This commit modifies the OpenChannel struct to include the full short
channel ID rather than simply the opening height. This new field will
be needed by an upcoming change to uniformly switch to using short
channel ID’s when forwarding HTLC’s due to the change in per-hop
payloads.

channeldb/db.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 
 	"github.com/boltdb/bolt"
+	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/roasbeef/btcd/btcec"
 	"github.com/roasbeef/btcd/wire"
 )
@@ -364,7 +365,9 @@ func fetchChannels(d *DB, pendingOnly bool) ([]*OpenChannel, error) {
 // MarkChannelAsOpen records the finalization of the funding process and marks
 // a channel as available for use. Additionally the height in which this
 // channel as opened will also be recorded within the database.
-func (d *DB) MarkChannelAsOpen(outpoint *wire.OutPoint, openHeight uint32) error {
+func (d *DB) MarkChannelAsOpen(outpoint *wire.OutPoint,
+	openLoc lnwire.ShortChannelID) error {
+
 	return d.Update(func(tx *bolt.Tx) error {
 		openChanBucket := tx.Bucket(openChannelBucket)
 		if openChanBucket == nil {
@@ -399,7 +402,7 @@ func (d *DB) MarkChannelAsOpen(outpoint *wire.OutPoint, openHeight uint32) error
 		infoCopy := make([]byte, len(confInfoBytes))
 		copy(infoCopy[:], confInfoBytes)
 
-		byteOrder.PutUint32(infoCopy[4:], openHeight)
+		byteOrder.PutUint64(infoCopy[4:], openLoc.ToUint64())
 
 		return openChanBucket.Put(confInfoKey, infoCopy)
 	})