Do not allow commiting to protected branch from online editor (#1502)

* Do not allow commiting to protected branch from online editor

* Add editor integration tests for adding new file and not allowing to add new file to protected branch

integrations/html_helper.go

@@ -0,0 +1,110 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package integrations
+
+import (
+	"bytes"
+
+	"golang.org/x/net/html"
+)
+
+type HtmlDoc struct {
+	doc  *html.Node
+	body *html.Node
+}
+
+func NewHtmlParser(content []byte) (*HtmlDoc, error) {
+	doc, err := html.Parse(bytes.NewReader(content))
+	if err != nil {
+		return nil, err
+	}
+
+	return &HtmlDoc{doc: doc}, nil
+}
+
+func (doc *HtmlDoc) GetBody() *html.Node {
+	if doc.body == nil {
+		var b *html.Node
+		var f func(*html.Node)
+		f = func(n *html.Node) {
+			if n.Type == html.ElementNode && n.Data == "body" {
+				b = n
+				return
+			}
+			for c := n.FirstChild; c != nil; c = c.NextSibling {
+				f(c)
+			}
+		}
+		f(doc.doc)
+		if b != nil {
+			doc.body = b
+		} else {
+			doc.body = doc.doc
+		}
+	}
+	return doc.body
+}
+
+func (doc *HtmlDoc) GetAttribute(n *html.Node, key string) (string, bool) {
+	for _, attr := range n.Attr {
+		if attr.Key == key {
+			return attr.Val, true
+		}
+	}
+	return "", false
+}
+
+func (doc *HtmlDoc) checkAttr(n *html.Node, attr, val string) bool {
+	if n.Type == html.ElementNode {
+		s, ok := doc.GetAttribute(n, attr)
+		if ok && s == val {
+			return true
+		}
+	}
+	return false
+}
+
+func (doc *HtmlDoc) traverse(n *html.Node, attr, val string) *html.Node {
+	if doc.checkAttr(n, attr, val) {
+		return n
+	}
+
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		result := doc.traverse(c, attr, val)
+		if result != nil {
+			return result
+		}
+	}
+
+	return nil
+}
+
+func (doc *HtmlDoc) GetElementById(id string) *html.Node {
+	return doc.traverse(doc.GetBody(), "id", id)
+}
+
+func (doc *HtmlDoc) GetInputValueById(id string) string {
+	inp := doc.GetElementById(id)
+	if inp == nil {
+		return ""
+	}
+
+	val, _ := doc.GetAttribute(inp, "value")
+	return val
+}
+
+func (doc *HtmlDoc) GetElementByName(name string) *html.Node {
+	return doc.traverse(doc.GetBody(), "name", name)
+}
+
+func (doc *HtmlDoc) GetInputValueByName(name string) string {
+	inp := doc.GetElementByName(name)
+	if inp == nil {
+		return ""
+	}
+
+	val, _ := doc.GetAttribute(inp, "value")
+	return val
+}