fix panic in offline calls of 'ipfs object stat'

merkledag_test.go

@@ -122,7 +122,7 @@ func SubtestNodeStat(t *testing.T, n *Node) {
 		return
 	}
 
-	if expected != actual {
+	if expected != *actual {
 		t.Error("n.Stat incorrect.\nexpect: %s\nactual: %s", expected, actual)
 	} else {
 		fmt.Printf("n.Stat correct: %s\n", actual)

node.go

@@ -160,18 +160,18 @@ func (n *Node) Size() (uint64, error) {
 }
 
 // Stat returns statistics on the node.
-func (n *Node) Stat() (NodeStat, error) {
+func (n *Node) Stat() (*NodeStat, error) {
 	enc, err := n.Encoded(false)
 	if err != nil {
-		return NodeStat{}, err
+		return nil, err
 	}
 
 	cumSize, err := n.Size()
 	if err != nil {
-		return NodeStat{}, err
+		return nil, err
 	}
 
-	return NodeStat{
+	return &NodeStat{
 		NumLinks:       len(n.Links),
 		BlockSize:      len(enc),
 		LinksSize:      len(enc) - len(n.Data), // includes framing.