[FIX] payment: Fix reference computation to avoid duplicates

- The method to compute the reference of a payment.transaction and avoid
  duplicate was missing some edge cases (for example if there was a '-'
  in the reference).

- The creation of transactions in the route /website_payment/pay was not
  checking for duplicate payment.transaction.

addons/payment/controllers/portal.py

@@ -109,6 +109,8 @@ class WebsitePayment(http.Controller):
         if order_id:
             values['sale_order_ids'] = [(6, 0, [order_id])]
 
+        reference_values = order_id and {'sale_order_ids': [(4, order_id)]} or {}
+        values['reference'] = request.env['payment.transaction']._compute_reference(values=reference_values, prefix=reference)
         tx = request.env['payment.transaction'].sudo().with_context(lang=None).create(values)
 
         render_values = {

addons/payment/models/payment_acquirer.py

@@ -792,11 +792,10 @@ class PaymentTransaction(models.Model):
         # Fetch the last reference
         # E.g. If the last reference is SO42-5, this query will return '-5'
         self._cr.execute('''
-                SELECT CAST(SUBSTRING(reference FROM '-\d+') AS INTEGER) AS suffix
+                SELECT CAST(SUBSTRING(reference FROM '-\d+$') AS INTEGER) AS suffix
                 FROM payment_transaction WHERE reference LIKE %s ORDER BY suffix
-            ''', [prefix + '%'])
+            ''', [prefix + '-%'])
         query_res = self._cr.fetchone()
-
         if query_res:
             # Increment the last reference by one
             suffix = '%s' % (-query_res[0] + 1)