[FIX] event_registration_partner_unique: avoid constraint on merge

If a user merge two contacts we should not raise the duplicates
constraint for that contact attendee.

TT45921

event_registration_partner_unique/__init__.py

@@ -1,3 +1,4 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 
 from . import models
+from . import wizards

event_registration_partner_unique/models/event.py

@@ -18,6 +18,8 @@ class EventEvent(models.Model):
     @api.constrains("forbid_duplicates", "registration_ids")
     def _check_forbid_duplicates(self):
         """Ensure no duplicated attendee are found in the event."""
+        if self.env.context.get("skip_registration_partner_unique"):
+            return
         return self.filtered(
             "forbid_duplicates"
         ).registration_ids._check_forbid_duplicates()

event_registration_partner_unique/wizards/__init__.py

@@ -0,0 +1 @@
+from . import base_partner_merge

event_registration_partner_unique/wizards/base_partner_merge.py

@@ -0,0 +1,14 @@
+# Copyright 2023 Tecnativa - David Vidal
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+from odoo import models
+
+
+class BasePartnerMergeAutomaticWizard(models.TransientModel):
+    _inherit = "base.partner.merge.automatic.wizard"
+
+    def action_merge(self):
+        """Inject context for avoiding the duplicated partner constraint"""
+        return super(
+            BasePartnerMergeAutomaticWizard,
+            self.with_context(skip_registration_partner_unique=True),
+        ).action_merge()