Merge pull request #201 from evanphx/b-null

Validate that the partialDoc is decoded correctly

Author: evanphx

v5/patch.go

@@ -38,6 +38,8 @@ var (
 ErrInvalid = errors.New("invalid state detected")
 ErrInvalidIndex = errors.New("invalid index referenced")
 
+ErrExpectedObject = errors.New("invalid value, expected object")
+
 rawJSONArray = []byte("[]")
 rawJSONObject = []byte("{}")
 rawJSONNull = []byte("null")
@@ -134,6 +136,10 @@ func (n *lazyNode) UnmarshalJSON(data []byte) error {
 }
 
 func (n *partialDoc) TrustMarshalJSON(buf *bytes.Buffer) error {
+if n.obj == nil {
+return ErrExpectedObject
+}
+
 if err := buf.WriteByte('{'); err != nil {
 return err
 }
@@ -557,6 +563,10 @@ func findObject(pd *container, path string, options *ApplyOptions) (container, s
 }
 
 func (d *partialDoc) set(key string, val *lazyNode, options *ApplyOptions) error {
+if d.obj == nil {
+return ErrExpectedObject
+}
+
 found := false
 for _, k := range d.keys {
 if k == key {
@@ -579,6 +589,11 @@ func (d *partialDoc) get(key string, options *ApplyOptions) (*lazyNode, error) {
 if key == "" {
 return d.self, nil
 }
+
+if d.obj == nil {
+return nil, ErrExpectedObject
+}
+
 v, ok := d.obj[key]
 if !ok {
 return v, errors.Wrapf(ErrMissing, "unable to get nonexistent key: %s", key)
@@ -587,6 +602,10 @@ func (d *partialDoc) get(key string, options *ApplyOptions) (*lazyNode, error) {
 }
 
 func (d *partialDoc) remove(key string, options *ApplyOptions) error {
+if d.obj == nil {
+return ErrExpectedObject
+}
+
 _, ok := d.obj[key]
 if !ok {
 if options.AllowMissingPathOnRemove {