[UTIL][Formatting] Mention title is not always defined

src/Util/Formatting.php

@@ -450,7 +450,7 @@ abstract class Formatting
  foreach ($points as $position => $mention) {
  $linkText = self::linkifyMentionArray($mention);
 
- $text = substr_replace($text, $linkText, $position-1, $mention['length']+1);
+ $text = substr_replace($text, $linkText, $position - 1, $mention['length'] + 1);
  }
 
  return [$text, $mentions];
@@ -471,7 +471,7 @@ abstract class Formatting
  }
 
  $output = HTML::html(['span' => ['attrs' => ['class' => 'h-card'],
- '@' . HTML::html(['a' => ['attrs' => $attrs, $mention['title']]], options: ['indent' => false]),
+ '@' . HTML::html(['a' => ['attrs' => $attrs, $mention['title'] ?? $mention['text']]], options: ['indent' => false]),
  ]], options: ['indent' => false, 'raw' => true]);
 
  Event::handle('EndLinkifyMention', [$mention, &$output]);