Render email addresses as such if followed by punctuation (go-gitea#27987)

Added the following characters to the regular expression for the email:

- ,
- ;
- ?
- !

Also added a test case.

- Fixes go-gitea#27616 

# Before

![image](https://github.com/go-gitea/gitea/assets/20454870/c57eac26-f281-43ef-a51d-9c9a81b63efa)

# After

![image](https://github.com/go-gitea/gitea/assets/20454870/fc7d5c08-4350-4af0-a7f0-d1444d2d75af)

Signed-off-by: Yarden Shoham <[email protected]>

Author: yardenshoham

modules/markup/html.go

@@ -66,7 +66,7 @@ var (
 	// well as the HTML5 spec:
 	//   http://spec.commonmark.org/0.28/#email-address
 	//   https://html.spec.whatwg.org/multipage/input.html#e-mail-state-(type%3Demail)
-	emailRegex = regexp.MustCompile("(?:\\s|^|\\(|\\[)([a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9]{2,}(?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+)(?:\\s|$|\\)|\\]|\\.(\\s|$))")
+	emailRegex = regexp.MustCompile("(?:\\s|^|\\(|\\[)([a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9]{2,}(?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)+)(?:\\s|$|\\)|\\]|;|,|\\?|!|\\.(\\s|$))")
 
 	// blackfriday extensions create IDs like fn:user-content-footnote
 	blackfridayExtRegex = regexp.MustCompile(`[^:]*:user-content-`)

modules/markup/html_test.go

@@ -264,6 +264,18 @@ func TestRender_email(t *testing.T) {
 		"send email to [email protected].",
 		`<p>send email to <a href="mailto:[email protected]" rel="nofollow">[email protected]</a>.</p>`)
 
+	test(
+		`[email protected],
+	[email protected].
+	[email protected];
+	[email protected]?
+	[email protected]!`,
+		`<p><a href="mailto:[email protected]" rel="nofollow">[email protected]</a>,<br/>
+<a href="mailto:[email protected]" rel="nofollow">[email protected]</a>.<br/>
+<a href="mailto:[email protected]" rel="nofollow">[email protected]</a>;<br/>
+<a href="mailto:[email protected]" rel="nofollow">[email protected]</a>?<br/>
+<a href="mailto:[email protected]" rel="nofollow">[email protected]</a>!</p>`)
+
 	// Test that should *not* be turned into email links
 	test(
 		"\"[email protected]\"",