[FIX] mail: only generate one next activity when setting automated actions at record update

Create an automated action to create a new activity on update of a record
(e.g. a CRM lead).
At update, many fields recompute may be triggered, triggering as many write.
Thus it would generate many activities.
We simply do nothing if we are in a recompute.

Coauthored by rco

opw 1904156

closes odoo/odoo#28498

addons/mail/models/ir_actions.py

@@ -94,6 +94,17 @@ class ServerActions(models.Model):
             return False
 
         records = self.env[action.model_id.model].browse(self._context.get('active_ids', self._context.get('active_id')))
+
+        old_values = action._context.get('old_values')
+        if old_values:
+            field_names = list(old_values[records[0].id])
+            field = records._fields[field_names[0]]
+            # Pick an arbitrary field; if it is marked to be recomputed,
+            # it means we are in an extraneous write triggered by the recompute.
+            # In this case, we should not create a new activity.
+            if records._recompute_check(field):
+                return False
+
         vals = {
             'summary': action.activity_summary or '',
             'note': action.activity_note or '',