v5/internal/json/encode.go

@@ -167,6 +167,19 @@ func Marshal(v any) ([]byte, error) {
 	return buf, nil
 }
 
+func MarshalEscaped(v any, escape bool) ([]byte, error) {
+	e := newEncodeState()
+	defer encodeStatePool.Put(e)
+
+	err := e.marshal(v, encOpts{escapeHTML: escape})
+	if err != nil {
+		return nil, err
+	}
+	buf := append([]byte(nil), e.Bytes()...)
+
+	return buf, nil
+}
+
 // MarshalIndent is like Marshal but applies Indent to format the output.
 // Each JSON element in the output will begin on a new line beginning with prefix
 // followed by one or more copies of indent according to the indentation nesting.

v5/merge.go

@@ -10,26 +10,26 @@ import (
 	"github.com/evanphx/json-patch/v5/internal/json"
 )
 
-func merge(cur, patch *lazyNode, mergeMerge bool) *lazyNode {
-	curDoc, err := cur.intoDoc()
+func merge(cur, patch *lazyNode, mergeMerge bool, options *ApplyOptions) *lazyNode {
+	curDoc, err := cur.intoDoc(options)
 
 	if err != nil {
-		pruneNulls(patch)
+		pruneNulls(patch, options)
 		return patch
 	}
 
-	patchDoc, err := patch.intoDoc()
+	patchDoc, err := patch.intoDoc(options)
 
 	if err != nil {
 		return patch
 	}
 
-	mergeDocs(curDoc, patchDoc, mergeMerge)
+	mergeDocs(curDoc, patchDoc, mergeMerge, options)
 
 	return cur
 }
 
-func mergeDocs(doc, patch *partialDoc, mergeMerge bool) {
+func mergeDocs(doc, patch *partialDoc, mergeMerge bool, options *ApplyOptions) {
 	for k, v := range patch.obj {
 		if v == nil {
 			if mergeMerge {
@@ -45,55 +45,55 @@ func mergeDocs(doc, patch *partialDoc, mergeMerge bool) {
 				}
 				doc.obj[k] = nil
 			} else {
-				_ = doc.remove(k, &ApplyOptions{})
+				_ = doc.remove(k, options)
 			}
 		} else {
 			cur, ok := doc.obj[k]
 
 			if !ok || cur == nil {
 				if !mergeMerge {
-					pruneNulls(v)
+					pruneNulls(v, options)
 				}
-				_ = doc.set(k, v, &ApplyOptions{})
+				_ = doc.set(k, v, options)
 			} else {
-				_ = doc.set(k, merge(cur, v, mergeMerge), &ApplyOptions{})
+				_ = doc.set(k, merge(cur, v, mergeMerge, options), options)
 			}
 		}
 	}
 }
 
-func pruneNulls(n *lazyNode) {
-	sub, err := n.intoDoc()
+func pruneNulls(n *lazyNode, options *ApplyOptions) {
+	sub, err := n.intoDoc(options)
 
 	if err == nil {
-		pruneDocNulls(sub)
+		pruneDocNulls(sub, options)
 	} else {
 		ary, err := n.intoAry()
 
 		if err == nil {
-			pruneAryNulls(ary)
+			pruneAryNulls(ary, options)
 		}
 	}
 }
 
-func pruneDocNulls(doc *partialDoc) *partialDoc {
+func pruneDocNulls(doc *partialDoc, options *ApplyOptions) *partialDoc {
 	for k, v := range doc.obj {
 		if v == nil {
 			_ = doc.remove(k, &ApplyOptions{})
 		} else {
-			pruneNulls(v)
+			pruneNulls(v, options)
 		}
 	}
 
 	return doc
 }
 
-func pruneAryNulls(ary *partialArray) *partialArray {
+func pruneAryNulls(ary *partialArray, options *ApplyOptions) *partialArray {
 	newAry := []*lazyNode{}
 
 	for _, v := range ary.nodes {
 		if v != nil {
-			pruneNulls(v)
+			pruneNulls(v, options)
 		}
 		newAry = append(newAry, v)
 	}
@@ -128,11 +128,17 @@ func doMergePatch(docData, patchData []byte, mergeMerge bool) ([]byte, error) {
 		return nil, errBadJSONPatch
 	}
 
-	doc := &partialDoc{}
+	options := NewApplyOptions()
+
+	doc := &partialDoc{
+		opts: options,
+	}
 
 	docErr := doc.UnmarshalJSON(docData)
 
-	patch := &partialDoc{}
+	patch := &partialDoc{
+		opts: options,
+	}
 
 	patchErr := patch.UnmarshalJSON(patchData)
 
@@ -158,7 +164,7 @@ func doMergePatch(docData, patchData []byte, mergeMerge bool) ([]byte, error) {
 			if mergeMerge {
 				doc = patch
 			} else {
-				doc = pruneDocNulls(patch)
+				doc = pruneDocNulls(patch, options)
 			}
 		} else {
 			patchAry := &partialArray{}
@@ -172,7 +178,7 @@ func doMergePatch(docData, patchData []byte, mergeMerge bool) ([]byte, error) {
 				return nil, errBadJSONPatch
 			}
 
-			pruneAryNulls(patchAry)
+			pruneAryNulls(patchAry, options)
 
 			out, patchErr := json.Marshal(patchAry.nodes)
 
@@ -183,7 +189,7 @@ func doMergePatch(docData, patchData []byte, mergeMerge bool) ([]byte, error) {
 			return out, nil
 		}
 	} else {
-		mergeDocs(doc, patch, mergeMerge)
+		mergeDocs(doc, patch, mergeMerge, options)
 	}
 
 	return json.Marshal(doc)

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")
@@ -60,6 +62,8 @@ type partialDoc struct {
 	self *lazyNode
 	keys []string
 	obj  map[string]*lazyNode
+
+	opts *ApplyOptions
 }
 
 type partialArray struct {
@@ -90,6 +94,8 @@ type ApplyOptions struct {
 	// EnsurePathExistsOnAdd instructs json-patch to recursively create the missing parts of path on "add" operation.
 	// Default to false.
 	EnsurePathExistsOnAdd bool
+
+	EscapeHTML bool
 }
 
 // NewApplyOptions creates a default set of options for calls to ApplyWithOptions.
@@ -99,6 +105,7 @@ func NewApplyOptions() *ApplyOptions {
 		AccumulatedCopySizeLimit: AccumulatedCopySizeLimit,
 		AllowMissingPathOnRemove: false,
 		EnsurePathExistsOnAdd:    false,
+		EscapeHTML:               true,
 	}
 }
 
@@ -134,16 +141,28 @@ 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
 	}
+	escaped := true
+
+	// n.opts should always be set, but in case we missed a case,
+	// guard.
+	if n.opts != nil {
+		escaped = n.opts.EscapeHTML
+	}
+
 	for i, k := range n.keys {
 		if i > 0 {
 			if err := buf.WriteByte(','); err != nil {
 				return err
 			}
 		}
-		key, err := json.Marshal(k)
+		key, err := json.MarshalEscaped(k, escaped)
 		if err != nil {
 			return err
 		}
@@ -153,7 +172,7 @@ func (n *partialDoc) TrustMarshalJSON(buf *bytes.Buffer) error {
 		if err := buf.WriteByte(':'); err != nil {
 			return err
 		}
-		value, err := json.Marshal(n.obj[k])
+		value, err := json.MarshalEscaped(n.obj[k], escaped)
 		if err != nil {
 			return err
 		}
@@ -194,11 +213,11 @@ func (n *partialArray) RedirectMarshalJSON() (interface{}, error) {
 	return n.nodes, nil
 }
 
-func deepCopy(src *lazyNode) (*lazyNode, int, error) {
+func deepCopy(src *lazyNode, options *ApplyOptions) (*lazyNode, int, error) {
 	if src == nil {
 		return nil, 0, nil
 	}
-	a, err := json.Marshal(src)
+	a, err := json.MarshalEscaped(src, options.EscapeHTML)
 	if err != nil {
 		return nil, 0, err
 	}
@@ -216,7 +235,7 @@ func (n *lazyNode) nextByte() byte {
 	return s[0]
 }
 
-func (n *lazyNode) intoDoc() (*partialDoc, error) {
+func (n *lazyNode) intoDoc(options *ApplyOptions) (*partialDoc, error) {
 	if n.which == eDoc {
 		return n.doc, nil
 	}
@@ -235,6 +254,7 @@ func (n *lazyNode) intoDoc() (*partialDoc, error) {
 		return nil, ErrInvalid
 	}
 
+	n.doc.opts = options
 	if err != nil {
 		return nil, err
 	}
@@ -545,7 +565,7 @@ func findObject(pd *container, path string, options *ApplyOptions) (container, s
 				return nil, ""
 			}
 		} else {
-			doc, err = next.intoDoc()
+			doc, err = next.intoDoc(options)
 
 			if err != nil {
 				return nil, ""
@@ -557,6 +577,10 @@ 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 +603,11 @@ 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 +616,10 @@ 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 {
@@ -750,6 +783,7 @@ func (p Patch) add(doc *container, op Operation, options *ApplyOptions) error {
 		} else {
 			pd = &partialDoc{
 				self: val,
+				opts: options,
 			}
 		}
 
@@ -855,7 +889,7 @@ func ensurePathExists(pd *container, path string, options *ApplyOptions) error {
 				newNode := newLazyNode(newRawMessage(rawJSONObject))
 
 				doc.add(part, newNode, options)
-				doc, err = newNode.intoDoc()
+				doc, err = newNode.intoDoc(options)
 				if err != nil {
 					return err
 				}
@@ -868,7 +902,7 @@ func ensurePathExists(pd *container, path string, options *ApplyOptions) error {
 					return err
 				}
 			} else {
-				doc, err = target.intoDoc()
+				doc, err = target.intoDoc(options)
 
 				if err != nil {
 					return err
@@ -954,6 +988,8 @@ func (p Patch) replace(doc *container, op Operation, options *ApplyOptions) erro
 				if !val.tryAry() {
 					return errors.Wrapf(err, "replace operation value must be object or array")
 				}
+			} else {
+				val.doc.opts = options
 			}
 		}
 
@@ -1115,7 +1151,7 @@ func (p Patch) copy(doc *container, op Operation, accumulatedCopySize *int64, op
 		return errors.Wrapf(ErrMissing, "copy operation does not apply: doc is missing destination path: %s", path)
 	}
 
-	valCopy, sz, err := deepCopy(val)
+	valCopy, sz, err := deepCopy(val, options)
 	if err != nil {
 		return errors.Wrapf(err, "error while performing deep copy")
 	}
@@ -1202,6 +1238,7 @@ func (p Patch) ApplyIndentWithOptions(doc []byte, indent string, options *ApplyO
 	} else {
 		pd = &partialDoc{
 			self: self,
+			opts: options,
 		}
 	}
 
@@ -1238,11 +1275,18 @@ func (p Patch) ApplyIndentWithOptions(doc []byte, indent string, options *ApplyO
 		}
 	}
 
-	if indent != "" {
-		return json.MarshalIndent(pd, "", indent)
+	data, err := json.MarshalEscaped(pd, options.EscapeHTML)
+	if err != nil {
+		return nil, err
+	}
+
+	if indent == "" {
+		return data, nil
 	}
 
-	return json.Marshal(pd)
+	var buf bytes.Buffer
+	json.Indent(&buf, data, "", indent)
+	return buf.Bytes(), nil
 }
 
 // From http://tools.ietf.org/html/rfc6901#section-4 :