Merge pull request #4952 from ipfs/fix/4951

report error source when failing to construct private network

core/core.go

@@ -193,7 +193,7 @@ func (n *IpfsNode) startOnlineServices(ctx context.Context, routingOption Routin
 	if swarmkey != nil {
 		protec, err = pnet.NewProtector(bytes.NewReader(swarmkey))
 		if err != nil {
-			return err
+			return fmt.Errorf("failed to configure private network: %s", err)
 		}
 		n.PNetFingerprint = protec.Fingerprint()
 		go func() {

repo/fsrepo/fsrepo.go

@@ -701,15 +701,11 @@ func (r *FSRepo) SwarmKey() ([]byte, error) {
 	f, err := os.Open(spath)
 	if err != nil {
 		if os.IsNotExist(err) {
-			return nil, nil
-		} else {
-			return nil, err
-		}
+			err = nil
 		}
-	defer f.Close()
-	if err != nil {
 		return nil, err
 	}
+	defer f.Close()
 
 	return ioutil.ReadAll(f)
 }