fix media description render for orgmode (go-gitea#26895)

- In org mode you can specify an description for media via the following
syntax `[[description][media link]]`. The description is then used as
title or alt.
- This patch fixes the rendering of the description by seperating the
description and non-description cases and using `org.String()`.
- Added unit tests.
- Inspired by
https://github.com/niklasfasching/go-org/blob/6eb20dbda93cb88c3503f7508dc78cbbc639378f/org/html_writer.go#L406-L427
- Resolves https://codeberg.org/Codeberg/Community/issues/848

(cherry picked from commit 8b8aab83113b34bade61964e2097ed497abc39e9)

Co-authored-by: Gusted <[email protected]>

Author: earl-warren

modules/markup/orgmode/orgmode.go

@@ -153,18 +153,31 @@ func (r *Writer) WriteRegularLink(l org.RegularLink) {
 		link = []byte(util.URLJoin(r.URLPrefix, lnk))
 	}
 
-	description := string(link)
-	if l.Description != nil {
-		description = r.WriteNodesAsString(l.Description...)
-	}
+	// Inspired by https://github.com/niklasfasching/go-org/blob/6eb20dbda93cb88c3503f7508dc78cbbc639378f/org/html_writer.go#L406-L427
 	switch l.Kind() {
 	case "image":
-		imageSrc := getMediaURL(link)
-		fmt.Fprintf(r, `<img src="%s" alt="%s" title="%s" />`, imageSrc, description, description)
+		if l.Description == nil {
+			imageSrc := getMediaURL(link)
+			fmt.Fprintf(r, `<img src="%s" alt="%s" title="%s" />`, imageSrc, link, link)
+		} else {
+			description := strings.TrimPrefix(org.String(l.Description...), "file:")
+			imageSrc := getMediaURL([]byte(description))
+			fmt.Fprintf(r, `<a href="%s"><img src="%s" alt="%s" /></a>`, link, imageSrc, imageSrc)
+		}
 	case "video":
-		videoSrc := getMediaURL(link)
-		fmt.Fprintf(r, `<video src="%s" title="%s">%s</video>`, videoSrc, description, description)
+		if l.Description == nil {
+			imageSrc := getMediaURL(link)
+			fmt.Fprintf(r, `<video src="%s" title="%s">%s</video>`, imageSrc, link, link)
+		} else {
+			description := strings.TrimPrefix(org.String(l.Description...), "file:")
+			videoSrc := getMediaURL([]byte(description))
+			fmt.Fprintf(r, `<a href="%s"><video src="%s" title="%s"></video></a>`, link, videoSrc, videoSrc)
+		}
 	default:
+		description := string(link)
+		if l.Description != nil {
+			description = r.WriteNodesAsString(l.Description...)
+		}
 		fmt.Fprintf(r, `<a href="%s" title="%s">%s</a>`, link, description, description)
 	}
 }

modules/markup/orgmode/orgmode_test.go

@@ -42,7 +42,7 @@ func TestRender_StandardLinks(t *testing.T) {
 		"<p><a href=\""+lnk+"\" title=\"WikiPage\">WikiPage</a></p>")
 }
 
-func TestRender_Images(t *testing.T) {
+func TestRender_Media(t *testing.T) {
 	setting.AppURL = AppURL
 	setting.AppSubURL = AppSubURL
 
@@ -60,6 +60,18 @@ func TestRender_Images(t *testing.T) {
 
 	test("[[file:"+url+"]]",
 		"<p><img src=\""+result+"\" alt=\""+result+"\" title=\""+result+"\" /></p>")
+
+	// With description.
+	test("[[https://example.com][https://example.com/example.svg]]",
+		`<p><a href="https://example.com"><img src="https://example.com/example.svg" alt="https://example.com/example.svg" /></a></p>`)
+	test("[[https://example.com][https://example.com/example.mp4]]",
+		`<p><a href="https://example.com"><video src="https://example.com/example.mp4" title="https://example.com/example.mp4"></video></a></p>`)
+
+	// Without description.
+	test("[[https://example.com/example.svg]]",
+		`<p><img src="https://example.com/example.svg" alt="https://example.com/example.svg" title="https://example.com/example.svg" /></p>`)
+	test("[[https://example.com/example.mp4]]",
+		`<p><video src="https://example.com/example.mp4" title="https://example.com/example.mp4">https://example.com/example.mp4</video></p>`)
 }
 
 func TestRender_Source(t *testing.T) {