fix(comments): Correctly treat end of message as end of code block/inline

Signed-off-by: Joas Schilling <coding@schilljs.com>

lib/private/Comments/Comment.php

@@ -198,7 +198,7 @@ class Comment implements IComment {
 		$message = $this->getMessage();
 		if ($supportMarkdown) {
 			// Strip fenced code blocks and inline code so mentions inside them are ignored
-			$message = preg_replace('/^```.*?^```|^~~~.*?^~~~/sm', '', $message);
+			$message = preg_replace('/^```.*?(^```|\z)|^~~~.*?(^~~~|\z)/sm', '', $message);
 			$message = preg_replace('/`[^`\n]*`/', '', $message);
 		}
 

tests/lib/Comments/CommentTest.php

@@ -240,6 +240,18 @@ class CommentTest extends TestCase {
 				null,
 				false,
 			],
+			[
+				'Mention @alice and `also @bob as end of text only applies to code blocks',
+				[['type' => 'user', 'id' => 'alice'], ['type' => 'user', 'id' => 'bob']],
+			],
+			[
+				"Mention @alice but not in unclosed fenced code block\n```\n@bob\n@charlie",
+				[['type' => 'user', 'id' => 'alice']],
+			],
+			[
+				"Mention @alice but not in unclosed tilde code block\n~~~\n@bob",
+				[['type' => 'user', 'id' => 'alice']],
+			],
 		];
 	}