[FIX] base_partner_merge: this wizard does not depend on mail anymore

We then extract the logging of the merge in a separate submethod, and
log in chatters only when available.

addons/mail/wizard/__init__.py

@@ -5,3 +5,4 @@ from . import invite
 from . import mail_compose_message
 from . import email_template_preview
 from . import base_module_uninstall
+from . import base_partner_merge

addons/mail/wizard/base_partner_merge.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+# Part of Odoo. See LICENSE file for full copyright and licensing details.
+from odoo import api, models, _
+
+
+class MergePartnerAutomatic(models.TransientModel):
+
+    _inherit = 'base.partner.merge.automatic.wizard'
+
+    @api.multi
+    def _log_merge_operation(self, src_partners, dst_partner):
+        super(MergePartnerAutomatic, self)._log_merge_operation(src_partners, dst_partner)
+        dst_partner.message_post(body='%s %s' % (_("Merged with the following partners:"), ", ".join('%s <%s> (ID %s)' % (p.name, p.email or 'n/a', p.id) for p in src_partners)))

odoo/addons/base/wizard/base_partner_merge.py

@@ -290,12 +290,15 @@ class MergePartnerAutomatic(models.TransientModel):
         self._update_reference_fields(src_partners, dst_partner)
         self._update_values(src_partners, dst_partner)
 
-        _logger.info('(uid = %s) merged the partners %r with %s', self._uid, src_partners.ids, dst_partner.id)
-        dst_partner.message_post(body='%s %s' % (_("Merged with the following partners:"), ", ".join('%s <%s> (ID %s)' % (p.name, p.email or 'n/a', p.id) for p in src_partners)))
+        self._log_merge_operation(src_partners, dst_partner)
 
         # delete source partner, since they are merged
         src_partners.unlink()
 
+    @api.multi
+    def _log_merge_operation(self, src_partners, dst_partner):
+        _logger.info('(uid = %s) merged the partners %r with %s', self._uid, src_partners.ids, dst_partner.id)
+
     # ----------------------------------------
     # Helpers
     # ----------------------------------------