[IMP] mail: trigger garbage collection of attachments from model ir.autovacuum

addons/mail/data/mail_data.xml

@@ -28,19 +28,6 @@
             <field name="priority">1000</field>
         </record>
 
-        <record id="ir_cron_mail_garbage_collect_attachments" model="ir.cron">
-            <field name="name">Garbage Collect Mail Attachments</field>
-            <field eval="True" name="active" />
-            <field name="user_id" ref="base.user_root" />
-            <field name="interval_number">1</field>
-            <field name="interval_type">weeks</field>
-            <field name="numbercall">-1</field>
-            <field eval="False" name="doall" />
-            <field name="model">mail.thread</field>
-            <field name="function">_garbage_collect_attachments</field>
-            <field name="args">()</field>
-        </record>
-
         <!-- Admin should not receivve emails at creation -->
         <record id="base.partner_root" model="res.partner">
             <field name="notify_email">none</field>

addons/mail/models/__init__.py

@@ -15,4 +15,5 @@ import res_users
 import res_config
 import update
 import ir_actions
+import ir_autovacuum
 import html2text

addons/mail/models/ir_autovacuum.py

@@ -0,0 +1,11 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+
+from openerp import models
+
+class AutoVacuum(models.TransientModel):
+    _inherit = 'ir.autovacuum'
+
+    def power_on(self, cr, uid, *args, **kwargs):
+        self.pool['mail.thread']._garbage_collect_attachments(cr, uid)
+        return super(AutoVacuum, self).power_on(cr, uid, *args, **kwargs)