In PO if product quantity = 3 and change quantity = 1 then received 1 quantity and 2 quantity is cancel. My question is if quantity = 3 and change quantity = 0 then received 0 and 3 quantity is cancel. In case, if quantity change become 0 then PO create backorder. I don't want if change quantity = 0 and create backorder.

I've already change code in arround addons stock/stock.py:

@api.cr_uid_ids_context
def do_transfer(self, cr, uid, picking_ids, context=None):
    """
        If no pack operation, we do simple action_done of the picking
        Otherwise, do the pack operations
    """
    if not context:
        context = {}
    stock_move_obj = self.pool.get('stock.move')
    for picking in self.browse(cr, uid, picking_ids, context=context):
        if not picking.pack_operation_ids:
            self.action_done(cr, uid, [picking.id], context=context)
            continue
        else:
            need_rereserve, all_op_processed = self.picking_recompute_remaining_quantities(cr, uid, picking, context=context)
            #create extra moves in the picking (unexpected product moves coming from pack operations)
            todo_move_ids = []
            if not all_op_processed:
                todo_move_ids += self._create_extra_moves(cr, uid, picking, context=context)

            #split move lines if needed
            toassign_move_ids = []
            for move in picking.move_lines:
                remaining_qty = move.remaining_qty
                if move.state in ('done', 'cancel'):
                    #ignore stock moves cancelled or already done
                    continue
                elif move.state == 'draft':
                    toassign_move_ids.append(move.id)
                if float_compare(remaining_qty, 0,  precision_rounding = move.product_id.uom_id.rounding) == 0:
                    if move.state in ('draft', 'assigned', 'confirmed'):
                        todo_move_ids.append(move.id)
                elif float_compare(remaining_qty,0, precision_rounding = move.product_id.uom_id.rounding) > 0 and \
                            float_compare(remaining_qty, move.product_qty, precision_rounding = move.product_id.uom_id.rounding) < 0:
                    new_move = stock_move_obj.split(cr, uid, move, remaining_qty, context=context)
                    todo_move_ids.append(move.id)
                    #Assign move as it was assigned before
                    toassign_move_ids.append(new_move)
            if need_rereserve or not all_op_processed: 
                if not picking.location_id.usage in ("supplier", "production", "inventory"):
                    self.rereserve_quants(cr, uid, picking, move_ids=todo_move_ids, context=context)
                self.do_recompute_remaining_quantities(cr, uid, [picking.id], context=context)
            if todo_move_ids and not context.get('do_only_split'):
                self.pool.get('stock.move').action_done_only(cr, uid, todo_move_ids, context=context)
            elif context.get('do_only_split'):
                context = dict(context, split=todo_move_ids)
        self._create_backorder(cr, uid, picking, context=context)
        if toassign_move_ids:
            stock_move_obj.action_assign(cr, uid, toassign_move_ids, context=context)
    return True