Refactor markup code (#31399)

1. use clearer names
2. remove deadcode
3. avoid name shadowing
4. eliminate some lint warnings

(cherry picked from commit 5a7376c0605415e63cb5b3b8f89ead01e567229b)

Conflicts:
	modules/markup/html.go
	simple code divergence, trivial logic

.deadcode-out

@@ -210,7 +210,6 @@ code.gitea.io/gitea/modules/json
 	StdJSON.Indent
 
 code.gitea.io/gitea/modules/markup
-	IsSameDomain
 	GetRendererByType
 	RenderString
 	IsMarkupFile

modules/markup/html.go

@@ -143,20 +143,6 @@ func CustomLinkURLSchemes(schemes []string) {
 	common.LinkRegex, _ = xurls.StrictMatchingScheme(strings.Join(withAuth, "|"))
 }
 
-// IsSameDomain checks if given url string has the same hostname as current Gitea instance
-func IsSameDomain(s string) bool {
-	if strings.HasPrefix(s, "/") {
-		return true
-	}
-	if uapp, err := url.Parse(setting.AppURL); err == nil {
-		if u, err := url.Parse(s); err == nil {
-			return u.Host == uapp.Host
-		}
-		return false
-	}
-	return false
-}
-
 type postProcessError struct {
 	context string
 	err     error
@@ -393,7 +379,7 @@ func visitNode(ctx *RenderContext, procs []processor, node *html.Node) {
 	// We ignore code and pre.
 	switch node.Type {
 	case html.TextNode:
-		textNode(ctx, procs, node)
+		processTextNodes(ctx, procs, node)
 	case html.ElementNode:
 		if node.Data == "img" {
 			for i, attr := range node.Attr {
@@ -436,15 +422,16 @@ func visitNode(ctx *RenderContext, procs []processor, node *html.Node) {
 		for n := node.FirstChild; n != nil; n = n.NextSibling {
 			visitNode(ctx, procs, n)
 		}
+	default:
 	}
 	// ignore everything else
 }
 
-// textNode runs the passed node through various processors, in order to handle
+// processTextNodes runs the passed node through various processors, in order to handle
 // all kinds of special links handled by the post-processing.
-func textNode(ctx *RenderContext, procs []processor, node *html.Node) {
+func processTextNodes(ctx *RenderContext, procs []processor, node *html.Node) {
-	for _, processor := range procs {
+	for _, p := range procs {
-		processor(ctx, node)
+		p(ctx, node)
 	}
 }
 

modules/markup/html_test.go

@@ -135,17 +135,6 @@ func TestRender_CrossReferences(t *testing.T) {
 		`<p><a href="`+urlWithQuery+`" rel="nofollow"><code>`+sha[:10]+`/README.md (L1-L5)</code></a></p>`)
 }
 
-func TestMisc_IsSameDomain(t *testing.T) {
-	setting.AppURL = markup.TestAppURL
-
-	sha := "b6dd6210eaebc915fd5be5579c58cce4da2e2579"
-	commit := util.URLJoin(markup.TestRepoURL, "commit", sha)
-
-	assert.True(t, markup.IsSameDomain(commit))
-	assert.False(t, markup.IsSameDomain("http://google.com/ncr"))
-	assert.False(t, markup.IsSameDomain("favicon.ico"))
-}
-
 func TestRender_links(t *testing.T) {
 	setting.AppURL = markup.TestAppURL