Adding upstream version 9.0.3.

Signed-off-by: Daniel Baumann <daniel@debian.org>

1 files changed, 393 insertions, 0 deletions

diff --git a/modules/markup/renderer.go b/modules/markup/renderer.go
new file mode 100644
index 0000000..2137302
--- /dev/null
+++ b/modules/markup/renderer.go
@@ -0,0 +1,393 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markup
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/yuin/goldmark/ast"
+)
+
+type RenderMetaMode string
+
+const (
+	RenderMetaAsDetails RenderMetaMode = "details" // default
+	RenderMetaAsNone    RenderMetaMode = "none"
+	RenderMetaAsTable   RenderMetaMode = "table"
+)
+
+type ProcessorHelper struct {
+	IsUsernameMentionable func(ctx context.Context, username string) bool
+	GetRepoFileBlob       func(ctx context.Context, ownerName, repoName, commitSha, filePath string, language *string) (*git.Blob, error)
+
+	ElementDir string // the direction of the elements, eg: "ltr", "rtl", "auto", default to no direction attribute
+}
+
+var DefaultProcessorHelper ProcessorHelper
+
+// Init initialize regexps for markdown parsing
+func Init(ph *ProcessorHelper) {
+	if ph != nil {
+		DefaultProcessorHelper = *ph
+	}
+
+	NewSanitizer()
+	if len(setting.Markdown.CustomURLSchemes) > 0 {
+		CustomLinkURLSchemes(setting.Markdown.CustomURLSchemes)
+	}
+
+	// since setting maybe changed extensions, this will reload all renderer extensions mapping
+	extRenderers = make(map[string]Renderer)
+	for _, renderer := range renderers {
+		for _, ext := range renderer.Extensions() {
+			extRenderers[strings.ToLower(ext)] = renderer
+		}
+	}
+}
+
+// Header holds the data about a header.
+type Header struct {
+	Level int
+	Text  string
+	ID    string
+}
+
+// RenderContext represents a render context
+type RenderContext struct {
+	Ctx              context.Context
+	RelativePath     string // relative path from tree root of the branch
+	Type             string
+	IsWiki           bool
+	Links            Links
+	Metas            map[string]string
+	DefaultLink      string
+	GitRepo          *git.Repository
+	ShaExistCache    map[string]bool
+	cancelFn         func()
+	SidebarTocNode   ast.Node
+	InStandalonePage bool // used by external render. the router "/org/repo/render/..." will output the rendered content in a standalone page
+}
+
+type Links struct {
+	AbsolutePrefix bool
+	Base           string
+	BranchPath     string
+	TreePath       string
+}
+
+func (l *Links) Prefix() string {
+	if l.AbsolutePrefix {
+		return setting.AppURL
+	}
+	return setting.AppSubURL
+}
+
+func (l *Links) HasBranchInfo() bool {
+	return l.BranchPath != ""
+}
+
+func (l *Links) SrcLink() string {
+	return util.URLJoin(l.Base, "src", l.BranchPath, l.TreePath)
+}
+
+func (l *Links) MediaLink() string {
+	return util.URLJoin(l.Base, "media", l.BranchPath, l.TreePath)
+}
+
+func (l *Links) RawLink() string {
+	return util.URLJoin(l.Base, "raw", l.BranchPath, l.TreePath)
+}
+
+func (l *Links) WikiLink() string {
+	return util.URLJoin(l.Base, "wiki")
+}
+
+func (l *Links) WikiRawLink() string {
+	return util.URLJoin(l.Base, "wiki/raw")
+}
+
+func (l *Links) ResolveMediaLink(isWiki bool) string {
+	if isWiki {
+		return l.WikiRawLink()
+	} else if l.HasBranchInfo() {
+		return l.MediaLink()
+	}
+	return l.Base
+}
+
+// Cancel runs any cleanup functions that have been registered for this Ctx
+func (ctx *RenderContext) Cancel() {
+	if ctx == nil {
+		return
+	}
+	ctx.ShaExistCache = map[string]bool{}
+	if ctx.cancelFn == nil {
+		return
+	}
+	ctx.cancelFn()
+}
+
+// AddCancel adds the provided fn as a Cleanup for this Ctx
+func (ctx *RenderContext) AddCancel(fn func()) {
+	if ctx == nil {
+		return
+	}
+	oldCancelFn := ctx.cancelFn
+	if oldCancelFn == nil {
+		ctx.cancelFn = fn
+		return
+	}
+	ctx.cancelFn = func() {
+		defer oldCancelFn()
+		fn()
+	}
+}
+
+// Renderer defines an interface for rendering markup file to HTML
+type Renderer interface {
+	Name() string // markup format name
+	Extensions() []string
+	SanitizerRules() []setting.MarkupSanitizerRule
+	Render(ctx *RenderContext, input io.Reader, output io.Writer) error
+}
+
+// PostProcessRenderer defines an interface for renderers who need post process
+type PostProcessRenderer interface {
+	NeedPostProcess() bool
+}
+
+// PostProcessRenderer defines an interface for external renderers
+type ExternalRenderer interface {
+	// SanitizerDisabled disabled sanitize if return true
+	SanitizerDisabled() bool
+
+	// DisplayInIFrame represents whether render the content with an iframe
+	DisplayInIFrame() bool
+}
+
+// RendererContentDetector detects if the content can be rendered
+// by specified renderer
+type RendererContentDetector interface {
+	CanRender(filename string, input io.Reader) bool
+}
+
+var (
+	extRenderers = make(map[string]Renderer)
+	renderers    = make(map[string]Renderer)
+)
+
+// RegisterRenderer registers a new markup file renderer
+func RegisterRenderer(renderer Renderer) {
+	renderers[renderer.Name()] = renderer
+	for _, ext := range renderer.Extensions() {
+		extRenderers[strings.ToLower(ext)] = renderer
+	}
+}
+
+// GetRendererByFileName get renderer by filename
+func GetRendererByFileName(filename string) Renderer {
+	extension := strings.ToLower(filepath.Ext(filename))
+	return extRenderers[extension]
+}
+
+// GetRendererByType returns a renderer according type
+func GetRendererByType(tp string) Renderer {
+	return renderers[tp]
+}
+
+// DetectRendererType detects the markup type of the content
+func DetectRendererType(filename string, input io.Reader) string {
+	buf, err := io.ReadAll(input)
+	if err != nil {
+		return ""
+	}
+	for _, renderer := range renderers {
+		if detector, ok := renderer.(RendererContentDetector); ok && detector.CanRender(filename, bytes.NewReader(buf)) {
+			return renderer.Name()
+		}
+	}
+	return ""
+}
+
+// Render renders markup file to HTML with all specific handling stuff.
+func Render(ctx *RenderContext, input io.Reader, output io.Writer) error {
+	if ctx.Type != "" {
+		return renderByType(ctx, input, output)
+	} else if ctx.RelativePath != "" {
+		return renderFile(ctx, input, output)
+	}
+	return errors.New("Render options both filename and type missing")
+}
+
+// RenderString renders Markup string to HTML with all specific handling stuff and return string
+func RenderString(ctx *RenderContext, content string) (string, error) {
+	var buf strings.Builder
+	if err := Render(ctx, strings.NewReader(content), &buf); err != nil {
+		return "", err
+	}
+	return buf.String(), nil
+}
+
+type nopCloser struct {
+	io.Writer
+}
+
+func (nopCloser) Close() error { return nil }
+
+func renderIFrame(ctx *RenderContext, output io.Writer) error {
+	// set height="0" ahead, otherwise the scrollHeight would be max(150, realHeight)
+	// at the moment, only "allow-scripts" is allowed for sandbox mode.
+	// "allow-same-origin" should never be used, it leads to XSS attack, and it makes the JS in iframe can access parent window's config and CSRF token
+	// TODO: when using dark theme, if the rendered content doesn't have proper style, the default text color is black, which is not easy to read
+	_, err := io.WriteString(output, fmt.Sprintf(`
+<iframe src="%s/%s/%s/render/%s/%s"
+name="giteaExternalRender"
+onload="this.height=giteaExternalRender.document.documentElement.scrollHeight"
+width="100%%" height="0" scrolling="no" frameborder="0" style="overflow: hidden"
+sandbox="allow-scripts"
+></iframe>`,
+		setting.AppSubURL,
+		url.PathEscape(ctx.Metas["user"]),
+		url.PathEscape(ctx.Metas["repo"]),
+		ctx.Metas["BranchNameSubURL"],
+		url.PathEscape(ctx.RelativePath),
+	))
+	return err
+}
+
+func render(ctx *RenderContext, renderer Renderer, input io.Reader, output io.Writer) error {
+	var wg sync.WaitGroup
+	var err error
+	pr, pw := io.Pipe()
+	defer func() {
+		_ = pr.Close()
+		_ = pw.Close()
+	}()
+
+	var pr2 io.ReadCloser
+	var pw2 io.WriteCloser
+
+	var sanitizerDisabled bool
+	if r, ok := renderer.(ExternalRenderer); ok {
+		sanitizerDisabled = r.SanitizerDisabled()
+	}
+
+	if !sanitizerDisabled {
+		pr2, pw2 = io.Pipe()
+		defer func() {
+			_ = pr2.Close()
+			_ = pw2.Close()
+		}()
+
+		wg.Add(1)
+		go func() {
+			err = SanitizeReader(pr2, renderer.Name(), output)
+			_ = pr2.Close()
+			wg.Done()
+		}()
+	} else {
+		pw2 = nopCloser{output}
+	}
+
+	wg.Add(1)
+	go func() {
+		if r, ok := renderer.(PostProcessRenderer); ok && r.NeedPostProcess() {
+			err = PostProcess(ctx, pr, pw2)
+		} else {
+			_, err = io.Copy(pw2, pr)
+		}
+		_ = pr.Close()
+		_ = pw2.Close()
+		wg.Done()
+	}()
+
+	if err1 := renderer.Render(ctx, input, pw); err1 != nil {
+		return err1
+	}
+	_ = pw.Close()
+
+	wg.Wait()
+	return err
+}
+
+// ErrUnsupportedRenderType represents
+type ErrUnsupportedRenderType struct {
+	Type string
+}
+
+func (err ErrUnsupportedRenderType) Error() string {
+	return fmt.Sprintf("Unsupported render type: %s", err.Type)
+}
+
+func renderByType(ctx *RenderContext, input io.Reader, output io.Writer) error {
+	if renderer, ok := renderers[ctx.Type]; ok {
+		return render(ctx, renderer, input, output)
+	}
+	return ErrUnsupportedRenderType{ctx.Type}
+}
+
+// ErrUnsupportedRenderExtension represents the error when extension doesn't supported to render
+type ErrUnsupportedRenderExtension struct {
+	Extension string
+}
+
+func IsErrUnsupportedRenderExtension(err error) bool {
+	_, ok := err.(ErrUnsupportedRenderExtension)
+	return ok
+}
+
+func (err ErrUnsupportedRenderExtension) Error() string {
+	return fmt.Sprintf("Unsupported render extension: %s", err.Extension)
+}
+
+func renderFile(ctx *RenderContext, input io.Reader, output io.Writer) error {
+	extension := strings.ToLower(filepath.Ext(ctx.RelativePath))
+	if renderer, ok := extRenderers[extension]; ok {
+		if r, ok := renderer.(ExternalRenderer); ok && r.DisplayInIFrame() {
+			if !ctx.InStandalonePage {
+				// for an external render, it could only output its content in a standalone page
+				// otherwise, a <iframe> should be outputted to embed the external rendered page
+				return renderIFrame(ctx, output)
+			}
+		}
+		return render(ctx, renderer, input, output)
+	}
+	return ErrUnsupportedRenderExtension{extension}
+}
+
+// Type returns if markup format via the filename
+func Type(filename string) string {
+	if parser := GetRendererByFileName(filename); parser != nil {
+		return parser.Name()
+	}
+	return ""
+}
+
+// IsMarkupFile reports whether file is a markup type file
+func IsMarkupFile(name, markup string) bool {
+	if parser := GetRendererByFileName(name); parser != nil {
+		return parser.Name() == markup
+	}
+	return false
+}
+
+func PreviewableExtensions() []string {
+	extensions := make([]string, 0, len(extRenderers))
+	for extension := range extRenderers {
+		extensions = append(extensions, extension)
+	}
+	return extensions
+}