set data and links nil if not present

License: MIT
Signed-off-by: Jeromy <jeromyj@gmail.com>

merkledag/coding.go

@@ -50,7 +50,9 @@ func (n *Node) Marshal() ([]byte, error) {
 
 func (n *Node) getPBNode() *pb.PBNode {
 	pbn := &pb.PBNode{}
-	pbn.Links = make([]*pb.PBLink, len(n.Links))
+	if len(n.Links) > 0 {
+		pbn.Links = make([]*pb.PBLink, len(n.Links))
+	}
 
 	sort.Stable(LinkSlice(n.Links)) // keep links sorted
 	for i, l := range n.Links {
@@ -60,7 +62,9 @@ func (n *Node) getPBNode() *pb.PBNode {
 		pbn.Links[i].Hash = []byte(l.Hash)
 	}
 
-	pbn.Data = n.Data
+	if len(n.Data) > 0 {
+		pbn.Data = n.Data
+	}
 	return pbn
 }
 

merkledag/node.go

@@ -176,11 +176,15 @@ func (n *Node) GetLinkedNode(ctx context.Context, ds DAGService, name string) (*
 // NOTE: does not make copies of Node objects in the links.
 func (n *Node) Copy() *Node {
 	nnode := new(Node)
-	nnode.Data = make([]byte, len(n.Data))
-	copy(nnode.Data, n.Data)
+	if len(n.Data) > 0 {
+		nnode.Data = make([]byte, len(n.Data))
+		copy(nnode.Data, n.Data)
+	}
 
-	nnode.Links = make([]*Link, len(n.Links))
-	copy(nnode.Links, n.Links)
+	if len(n.Links) > 0 {
+		nnode.Links = make([]*Link, len(n.Links))
+		copy(nnode.Links, n.Links)
+	}
 	return nnode
 }
 

merkledag/utils/utils_test.go

@@ -85,8 +85,8 @@ func TestInsertNode(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if k.B58String() != "QmThorWojP6YzLJwDukxiYCoKQSwyrMCvdt4WZ6rPm221t" {
-		t.Fatal("output was different than expected")
+	if k.B58String() != "QmZ8yeT9uD6ouJPNAYt62XffYuXBT6b4mP4obRSE9cJrSt" {
+		t.Fatal("output was different than expected: ", k)
 	}
 }
 

test/sharness/t0051-object.sh

@@ -234,6 +234,12 @@ test_object_cmd() {
 
 	test_patch_create_path $EMPTY a/b/b/b/b $FILE
 
+	test_expect_success "can create blank object" '
+		BLANK=$(ipfs object new)
+	'
+
+	test_patch_create_path $BLANK a $FILE
+
 	test_expect_success "create bad path fails" '
 		test_must_fail ipfs object patch --create $EMPTY add-link / $FILE
 	'