[IMP] mail: don't send attachment if the link is in the email

If the user send an email with a '/web/content' or /web/image' link in
the body, the attachment are not send by email to not to increase the
size of the email unnecessarily.

addons/mail/models/mail_mail.py

@@ -6,6 +6,7 @@ import datetime
 import logging
 import psycopg2
 import threading
+import re
 
 from collections import defaultdict
 from email.utils import formataddr
@@ -252,6 +253,7 @@ class MailMail(models.Model):
     @api.multi
     def _send(self, auto_commit=False, raise_exception=False, smtp_session=None):
         IrMailServer = self.env['ir.mail_server']
+        IrAttachment = self.env['ir.attachment']
         for mail_id in self.ids:
             success_pids = []
             failure_type = 'NONE'
@@ -263,11 +265,18 @@ class MailMail(models.Model):
                     if mail.state != 'exception' and mail.auto_delete:
                         mail.sudo().unlink()
                     continue
+
+                # remove attachments if user send the link with the access_token
+                body = mail.body_html or ''
+                attachments = mail.attachment_ids
+                for link in re.findall(r'/web/(?:content|image)/([0-9]+)', body):
+                    attachments = attachments - IrAttachment.browse(int(link))
+
                 # load attachment binary data with a separate read(), as prefetching all
                 # `datas` (binary field) could bloat the browse cache, triggerring
                 # soft/hard mem limits with temporary data.
                 attachments = [(a['datas_fname'], base64.b64decode(a['datas']), a['mimetype'])
-                               for a in mail.attachment_ids.sudo().read(['datas_fname', 'datas', 'mimetype'])]
+                               for a in attachments.sudo().read(['datas_fname', 'datas', 'mimetype'])]
 
                 # specific behavior to customize the send email for notified partners
                 email_list = []