rpcserver: add wallet sync check to OpenChannel

lntest/itest/lnd_test.go

@@ -214,9 +214,15 @@ func openChannelAndAssert(ctx context.Context, t *harnessTest,
 	net *lntest.NetworkHarness, alice, bob *lntest.HarnessNode,
 	p lntest.OpenChannelParams) *lnrpc.ChannelPoint {
 
-	chanOpenUpdate, err := net.OpenChannel(
+	// Wait until we are able to fund a channel successfully. This wait
-		ctx, alice, bob, p,
+	// prevents us from erroring out when trying to create a channel while
-	)
+	// the node is starting up.
+	var chanOpenUpdate lnrpc.Lightning_OpenChannelClient
+	err := wait.NoError(func() error {
+		var err error
+		chanOpenUpdate, err = net.OpenChannel(ctx, alice, bob, p)
+		return err
+	}, defaultTimeout)
 	if err != nil {
 		t.Fatalf("unable to open channel: %v", err)
 	}

rpcserver.go

@@ -1616,6 +1616,17 @@ func (r *rpcServer) OpenChannel(in *lnrpc.OpenChannelRequest,
 		return ErrServerNotActive
 	}
 
+	// Creation of channels before the wallet syncs up is currently
+	// disallowed.
+	isSynced, _, err := r.server.cc.wallet.IsSynced()
+	if err != nil {
+		return err
+	}
+	if !isSynced {
+		return errors.New("channels cannot be created before the " +
+			"wallet is fully synced")
+	}
+
 	localFundingAmt := btcutil.Amount(in.LocalFundingAmount)
 	remoteInitialBalance := btcutil.Amount(in.PushSat)
 	minHtlcIn := lnwire.MilliSatoshi(in.MinHtlcMsat)