删除好友聊天记录，修改上一条为最后一条信息

app/enterprise/controller/Im.php

@@ -444,6 +444,12 @@ class Im extends BaseController
         $map = ['id' => $id];
         $message = Message::where($map)->find();
         if ($message) {
+            // 如果是最后一条消息，需要将上一条设置为最后一条
+            if($message['is_last']){
+                $where = " msg_id < {$message['msg_id']} and chat_identify = '{$message['chat_identify']}'"
+                    . " and (find_in_set('{$this->uid}', del_user) = 0 or del_user is null)";
+                Message::where($where)->order('msg_id desc')->limit(1)->update(['is_last'=>1]);
+            }
             if ($message['is_group'] == 1) {
                 if ($message['del_user']) {
                     $message->del_user .= ',' . $this->userInfo['user_id'];

app/enterprise/model/User.php

@@ -250,7 +250,8 @@ class User extends BaseModel
                   if ($val['del_user']) {
                      $delUser = explode(',', $val['del_user']);
                      if (in_array($user_id, $delUser)) {
-                        $content = "";
+                        //$content = "";
+                         continue;
                      }
                   }
                   $list_chart[$k]['type'] = $val['type'];