PayPal webhook 不发邮件

webht/third_party/paypal/controllers/index.php

@@ -963,7 +963,10 @@ class Index extends CI_Controller {
 
             //添加邮件发送记录
             $webhook_memo = json_decode($item->pn_memo);
-            $is_webhook = substr($webhook_memo->id, 0, 2)==="WH" ? true : false;
+            $is_webhook = false;
+            if (isset($webhook_memo->id) && substr($webhook_memo->id, 0, 2)==="WH") {
+                $is_webhook = true;
+            }
             if ($item->pn_send !== 'send' && false===$is_webhook) {
                 //给外联发送通知邮件
                 $fromName = !empty($item->pn_payer) ? $item->pn_payer : '';