Step to reproduce: - Create an expense for an expense product which has a cost Current behaviour: - Expense's unit price is modifiable which shouldn't be the case according to the help message of hr.expense.unit_amount Behaviour after PR: - Expense unit price is only modifiable is there is no unit_amount (unit_amount = 0) opw-2781040 closes odoo/odoo#90014 X-original-commit: 44b6d60de301651e52df4c41e32e38d23b0a154e Signed-off-by: Kevin Baptiste <kba@odoo.com>