fix: assign fallback avatar on registration

server/app/api/logic/LoginLogic.php

@@ -50,7 +50,7 @@ class LoginLogic extends BaseLogic
             $userSn = User::createUserSn();
             $passwordSalt = Config::get('project.unique_identification');
             $password = create_password($params['password'], $passwordSalt);
-            $avatar = ConfigService::get('default_image', 'user_avatar');
+            $avatar = self::getDefaultUserAvatar();
             $inviteCode = User::createInviteCode();
 
             $inviterId = 0;
@@ -128,7 +128,7 @@ class LoginLogic extends BaseLogic
                     // is_bind_mobile: sms_upload匹配=1，缓存码匹配但sms_upload不匹配=0，都不匹配=0
                     $isPhoneReal = $smsMatched ? 1 : 0;
                     $userSn = User::createUserSn();
-                    $avatar = ConfigService::get('default_image', 'user_avatar');
+                    $avatar = self::getDefaultUserAvatar();
                     $inviteCode = User::createInviteCode();
                     $inviterId = 0;
                     if (!empty($params['inviter_code'])) {
@@ -216,6 +216,15 @@ class LoginLogic extends BaseLogic
         return UserTokenService::expireToken($userInfo['token']);
     }
 
+    /**
+     * 获取注册用户默认头像，后台配置为空时回退到项目内置头像。
+     */
+    private static function getDefaultUserAvatar(): string
+    {
+        $defaultAvatar = (string) Config::get('project.default_image.user_avatar', '');
+        return (string) ConfigService::get('default_image', 'user_avatar', $defaultAvatar) ?: $defaultAvatar;
+    }
+
 
     /**
      * @notes 获取微信请求code的链接