server: directly add missing edge to graph DB

With the graph refactor work done in the last release, some extra
validation in the graph Builder has resurfaced the bug. So here we just
let the "add missing edge" logic directly route through to the graph DB
instead of going through the graph Builder where the extra checks are.
the extra check in question is setting the funding script so that the
chain view can then be updated - but i dont think this is important for
our own channels since this chainview is used to know when a channel can
be pruned from the graph (we would not prune our own channels anyways).

Author: ellemouton

routing/localchans/manager.go

@@ -50,6 +50,10 @@ type Manager struct {
 		error)
 
 	// AddEdge is used to add edge/channel to the topology of the router.
+	//
+	// NOTE: this is only used to recreate our own missing edges during
+	// policy updates. This is a workaround for the following issue:
+	// https://github.com/lightningnetwork/lnd/issues/7261
 	AddEdge func(ctx context.Context, edge *models.ChannelEdgeInfo) error
 
 	// policyUpdateLock ensures that the database and the link do not fall

server.go

@@ -1128,7 +1128,7 @@ func newServer(ctx context.Context, cfg *Config, listenAddrs []net.Addr,
 		DefaultRoutingPolicy: cc.RoutingPolicy,
 		ForAllOutgoingChannels: func(ctx context.Context,
 			cb func(*models.ChannelEdgeInfo,
-				*models.ChannelEdgePolicy) error,
+			*models.ChannelEdgePolicy) error,
 			reset func()) error {
 
 			return s.graphDB.ForEachNodeChannel(ctx, selfVertex,
@@ -1148,7 +1148,11 @@ func newServer(ctx context.Context, cfg *Config, listenAddrs []net.Addr,
 		AddEdge: func(ctx context.Context,
 			edge *models.ChannelEdgeInfo) error {
 
-			return s.graphBuilder.AddEdge(ctx, edge)
+			// AddEdge is only called for our own local channels, so
+			// we skip the extra validation done by the graph
+			// builder here and instead write the edge directly to
+			// the graph database.
+			return s.graphDB.AddChannelEdge(ctx, edge)
 		},
 	}