Before this commit: Duplicating the contact that is linked to an attendee of a course also creates a copy of an attendee as well. After this commit: It does not create duplicate attendee in course. Task-3253983 closes odoo/odoo#126244 X-original-commit: 4af091bd62243db243555d46b97cc7af49ceeeb1 Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com> Signed-off-by: Mayur Raj Sinh Rathod (mrsr) <mrsr@odoo.com>