第一步：利用评论表单email，写入邮箱信息到MySQL

在 engine/modules/addcomments.php 查找：

$weburl = $_POST['weburl'];
			if( $is_logged ) $db->query( "INSERT INTO " . PREFIX . "_comments (post_id, user_id, date, autor, email, text, ip, is_register, approve, parent,weburl) values ('{$post_id}', '{$member_id['user_id']}', '{$time}', '{$name}', '{$mail}', '{$comments}', '{$_IP}', '1', '{$where_approve}', '{$parent}', '{$weburl}')" );
			else $db->query( "INSERT INTO " . PREFIX . "_comments (post_id, date, autor, email, text, ip, is_register, approve, parent,weburl) values ('{$post_id}', '{$time}', '{$name}', '{$mail}', '{$comments}', '{$_IP}', '0', '{$where_approve}', '{$parent}', '{$weburl}')" );

上面这段代码是记录评论URL而修改的，如果你没有用 guest_url v1.0 插件，则应该查找：

if( $row['gast_email'] != "" ) {

				$tpl->set( '{author}', "<a href=\"mailto:".htmlspecialchars($row['gast_email'], ENT_QUOTES, $config['charset'])."\">" . $row['gast_name'] . "</a>" );

上面这段代码是游客URL而修改的，如果你没用 guest_url v1.0 插件（替换为上面的代码），否则应替换为（这里将weburl和mail合并，不然会冲突）：

第二步：guestfoto（写入到数据库的邮箱，详见第一步）替换foto（默认头像）以获取邮箱相关联的头像。

Gravatar官方

const md5 = require( 'md5' );
  
function getGravatarURL( email ) {
  // Trim leading and trailing whitespace from
  // an email address and force all characters
  // to lower case
  const address = String( email ).trim().toLowerCase();

  // Create an MD5 hash of the final string
  const hash = md5( address );

  // Grab the actual image URL
  return `https://www.gravatar.cn/avatar/${ hash }`;
}

function get_gravatar_url( $email ) {
  // Trim leading and trailing whitespace from
  // an email address and force all characters
  // to lower case
  $address = strtolower( trim( $email ) );

  // Create an MD5 hash of the final string
  $hash = md5( $address );

  // Grab the actual image URL
  return 'https://www.gravatar.cn/avatar/' . $hash;
}

if ( count(explode("@", $row['foto'])) == 2 ) {

			$tpl->set( '{foto}', 'https://cravatar.cn/avatar/' . md5(trim($row['foto'])) . '?s=' . intval($user_group[$row['user_group']]['max_foto']) );

		} else {

			if( $row['foto'] ) {

				if (strpos($row['foto'], "//") === 0) $avatar = "http:".$row['foto']; else $avatar = $row['foto'];

				$avatar = @parse_url ( $avatar );

				if($avatar['host']) {

					$tpl->set( '{foto}', $row['foto'] );

				} else $tpl->set( '{foto}', $config['http_home_url'] . "uploads/fotos/" . $row['foto'] );

			} else $tpl->set( '{foto}', "{THEME}/dleimages/noavatar.png" );

		}

Gravatar-v1.3 XML

Guest_url v1.0 双生 XML

Gravatar.cn XML