Markdown task list improvements (#13952)

* Markdown task list improvements

- Remove `.ui` class and wrappers to prevent fomantic from messing with it.
- Change rendered HTML to match GitHub.
- Add custom styling for the checkboxes.

* fix unittest

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

4 files changed, 10 insertions, 10 deletions

diff --git a/modules/markup/markdown/goldmark.go b/modules/markup/markdown/goldmark.go
index 9447424644..f9fd6eb976 100644
--- a/modules/markup/markdown/goldmark.go
+++ b/modules/markup/markdown/goldmark.go
@@ -357,9 +357,9 @@ func (r *HTMLRenderer) renderTaskCheckBoxListItem(w util.BufWriter, source []byt
 		}
 		var err error
 		if n.IsChecked {
-			_, err = w.WriteString(`<span class="ui checked checkbox"><input type="checkbox" checked="" readonly="readonly"` + end + `<label>`)
+			_, err = w.WriteString(`<input type="checkbox" disabled="" checked=""` + end)
 		} else {
-			_, err = w.WriteString(`<span class="ui checkbox"><input type="checkbox" readonly="readonly"` + end + `<label>`)
+			_, err = w.WriteString(`<input type="checkbox" disabled=""` + end)
 		}
 		if err != nil {
 			return ast.WalkStop, err
@@ -371,7 +371,7 @@ func (r *HTMLRenderer) renderTaskCheckBoxListItem(w util.BufWriter, source []byt
 			}
 		}
 	} else {
-		_, _ = w.WriteString("</label></span></li>\n")
+		_, _ = w.WriteString("</li>\n")
 	}
 	return ast.WalkContinue, nil
 }
diff --git a/modules/markup/markdown/markdown_test.go b/modules/markup/markdown/markdown_test.go
index 7f27a43a7d..89005fc25d 100644
--- a/modules/markup/markdown/markdown_test.go
+++ b/modules/markup/markdown/markdown_test.go
@@ -142,9 +142,9 @@ func testAnswers(baseURLContent, baseURLImages string) []string {
 <p>(from <a href="https://www.markdownguide.org/extended-syntax/" rel="nofollow">https://www.markdownguide.org/extended-syntax/</a>)</p>
 <h3 id="user-content-checkboxes">Checkboxes</h3>
 <ul>
-<li class="task-list-item"><span class="ui checkbox"><input type="checkbox" readonly="readonly"/><label>unchecked</label></span></li>
-<li class="task-list-item"><span class="ui checked checkbox"><input type="checkbox" checked="" readonly="readonly"/><label>checked</label></span></li>
-<li class="task-list-item"><span class="ui checkbox"><input type="checkbox" readonly="readonly"/><label>still unchecked</label></span></li>
+<li class="task-list-item"><input type="checkbox" disabled=""/>unchecked</li>
+<li class="task-list-item"><input type="checkbox" disabled="" checked=""/>checked</li>
+<li class="task-list-item"><input type="checkbox" disabled=""/>still unchecked</li>
 </ul>
 <h3 id="user-content-definition-list">Definition list</h3>
 <dl>
diff --git a/modules/markup/sanitizer.go b/modules/markup/sanitizer.go
index ba73650bdf..9214a75fb3 100644
--- a/modules/markup/sanitizer.go
+++ b/modules/markup/sanitizer.go
@@ -43,7 +43,7 @@ func ReplaceSanitizer() {
 
 	// Checkboxes
 	sanitizer.policy.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
-	sanitizer.policy.AllowAttrs("checked", "disabled", "readonly").OnElements("input")
+	sanitizer.policy.AllowAttrs("checked", "disabled").OnElements("input")
 
 	// Custom URL-Schemes
 	sanitizer.policy.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
@@ -66,8 +66,8 @@ func ReplaceSanitizer() {
 	// Allow classes for emojis
 	sanitizer.policy.AllowAttrs("class").Matching(regexp.MustCompile(`emoji`)).OnElements("img")
 
-	// Allow icons, checkboxes, emojis, and chroma syntax on span
-	sanitizer.policy.AllowAttrs("class").Matching(regexp.MustCompile(`^((icon(\s+[\p{L}\p{N}_-]+)+)|(ui checkbox)|(ui checked checkbox)|(emoji))$|^([a-z][a-z0-9]{0,2})$`)).OnElements("span")
+	// Allow icons, emojis, and chroma syntax on span
+	sanitizer.policy.AllowAttrs("class").Matching(regexp.MustCompile(`^((icon(\s+[\p{L}\p{N}_-]+)+)|(emoji))$|^([a-z][a-z0-9]{0,2})$`)).OnElements("span")
 
 	// Allow generally safe attributes
 	generalSafeAttrs := []string{"abbr", "accept", "accept-charset",
diff --git a/modules/markup/sanitizer_test.go b/modules/markup/sanitizer_test.go
index 3e8dcecd50..63b70166d8 100644
--- a/modules/markup/sanitizer_test.go
+++ b/modules/markup/sanitizer_test.go
@@ -40,7 +40,7 @@ func Test_Sanitizer(t *testing.T) {
 		`<kbd>Ctrl + C</kbd>`, `<kbd>Ctrl + C</kbd>`,
 		`<i class="dropdown icon">NAUGHTY</i>`, `<i>NAUGHTY</i>`,
 		`<i class="icon dropdown"></i>`, `<i class="icon dropdown"></i>`,
-		`<span class="ui checkbox"><input type="checkbox" readonly="readonly"/><label>unchecked</label></span>`, `<span class="ui checkbox"><input type="checkbox" readonly="readonly"/><label>unchecked</label></span>`,
+		`<input type="checkbox" disabled=""/>unchecked`, `<input type="checkbox" disabled=""/>unchecked`,
 		`<span class="emoji dropdown">NAUGHTY</span>`, `<span>NAUGHTY</span>`,
 		`<span class="emoji">contents</span>`, `<span class="emoji">contents</span>`,
 	}