Fix period in remote usernames (#1533)

Author: melroy89

src/Service/MentionManager.php

@@ -78,34 +78,56 @@ function ($val) {
         );
     }
 
-    public function extract(?string $val, $type = self::ALL): ?array
+    /**
+     * Try to extract mentions from the body (eg. @[email protected]).
+     *
+     * @param val Body input string
+     * @param type Type of mentions to extract (ALL, LOCAL only or REMOTE only)
+     *
+     * @return string[]
+     */
+    public function extract(?string $body, $type = self::ALL): ?array
     {
-        if (!$val) {
+        if (!$body) {
             return null;
         }
 
         $result = match ($type) {
-            self::ALL => array_merge($this->byApPrefix($val), $this->byPrefix($val)),
-            self::LOCAL => $this->byPrefix($val),
-            self::REMOTE => $this->byApPrefix($val),
+            self::ALL => array_merge($this->byApPrefix($body), $this->byPrefix($body)),
+            self::LOCAL => $this->byPrefix($body),
+            self::REMOTE => $this->byApPrefix($body),
         };
 
         $result = array_map(fn ($val) => trim($val), $result);
 
         return \count($result) ? array_unique($result) : null;
     }
 
+    /**
+     * Remote activitypub prefix, like @[email protected].
+     *
+     * @param value Input string
+     *
+     * @return string[]
+     */
     private function byApPrefix(string $value): array
     {
         preg_match_all(
-            '/(?<!\/)\B@(\w{1,30})(@)(([\pL\pN\pS\pM\-\_]++\.)+[\pL\pN\pM]++|[a-z0-9\-\_]++)/u',
+            '/(?<!\/)\B@([a-zA-Z0-9._-]+@?)(@)(([\pL\pN\pS\pM\-\_]++\.)+[\pL\pN\pM]++|[a-z0-9\-\_]++)/u',
             $value,
             $matches
         );
 
         return \count($matches[0]) ? array_unique(array_values($matches[0])) : [];
     }
 
+    /**
+     * Local username prefix, like @username.
+     *
+     * @param value Input string
+     *
+     * @return string[]
+     */
     private function byPrefix(string $value): array
     {
         preg_match_all('/(?<!\/)\B@([a-zA-Z0-9_-]{1,30}@?)/u', $value, $matches);