https://github.com/odoo/odoo/blob/b192431aeecc59b48898ce9c6f276b82d65cbfa6/addons/stock/models/stock_move.py#L1026

rounding_method ='UP'
I think it **need be changed to:**
rounding_method ='HALF-UP'

I get this message then I Verify new Delivery(stock.picking):

> The initial demand has been updated.
> My Product
> Quantity : 5.951 -> 5.949999999999999 

and
> The initial demand has been updated.
> My Product
> Quantity : 5.951 -> 5.951 


How I did it(you can also repeat this error): Create new Product > add Qty on hand > Create SO > Add Product with quantity 5.5 > Verify > open Delivery > add Delivered qty 5.95 > Verify > Get trouble: odoo change my qty to 5.951
![default](https://user-images.githubusercontent.com/34191760/39213952-9b246470-481b-11e8-8e06-a074b1044536.png)

You can try execute in python:
5.95 - 5.5 = 0.4500000000000002

Look at the code:
```
            extra_move_quantity = float_round(
                self.quantity_done - self.product_uom_qty,
                precision_rounding=self.product_uom.rounding,
                rounding_method ='UP')
```
if you setup parameters like this:
```
            0.451 = float_round(
                5.95 - 5.5,
                precision_rounding=self.product_uom.rounding,
                rounding_method ='UP')
```
Then you get 0.451.  This is wrong!
Try:
```
            0.45 = float_round(
                5.95 - 5.5,
                precision_rounding=self.product_uom.rounding,
                rounding_method ='HALF-UP')
```
0.45 = 5.95 - 5.5
""" According to this field, the button that calls `action_show_details` will be displayed
        to work on a move from its picking form view, or not.
        """
        for move in self:
            if not move.product_id:
                move.show_details_visible = False
                continue
            multi_locations_enabled = False
            if self.user_has_groups('stock.group_stock_multi_locations'):
                multi_locations_enabled = move.location_id.child_ids or move.location_dest_id.child_ids
            has_package = move.move_line_ids.mapped('package_id') | move.move_line_ids.mapped('result_package_id')
            consignment_enabled = self.user_has_groups('stock.group_tracking_owner')
            if move.picking_id.picking_type_id.show_operations is False\
                    and (move.state != 'draft' or (not self._context.get('planned_picking') and move.state == 'draft'))\
                    and (multi_locations_enabled or move.has_tracking != 'none' or len(move.move_line_ids) > 1 or has_package or consignment_enabled):
                move.show_details_visible = True
            else:
                move.show_details_visible = False
    def _compute_show_reserved_availability(self):
        """ This field is only of use in an attrs in the picking view, in order to hide the
        "available" column if the move is coming from a supplier.
        """
        for move in self:
            move.show_reserved_availability = not move.location_id.usage == 'supplier'
    @api.depends('state', 'picking_id')
    def _compute_is_initial_demand_editable(self):