[FIX] account: multi-post in order

When we post multiple draft moves at the same time, the numbering should
be done by starting with the oldest one up to the newest.

closes odoo/odoo#41138

X-original-commit: 5b745eb61377e5b4532f2e370f9b1559a9b66c0a
Related: odoo/enterprise#6975
Signed-off-by: Quentin De Paoli (qdp) <qdp@openerp.com>

addons/account/wizard/account_validate_account_move.py

@@ -9,10 +9,7 @@ class ValidateAccountMove(models.TransientModel):
     def validate_move(self):
         context = dict(self._context or {})
         moves = self.env['account.move'].browse(context.get('active_ids'))
-        move_to_post = self.env['account.move']
-        for move in moves:
-            if move.state == 'draft':
-                move_to_post += move
+        move_to_post = moves.filtered(lambda m: m.state == 'draft').sorted(lambda m: (m.date, m.ref, m.id))
         if not move_to_post:
             raise UserError(_('There are no journal items in the draft state to post.'))
         move_to_post.post()