Impacted versions:
11.0

I don't know if it is an issue, but I think is strange.

`product_qty` is in unit of `product` : https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L240
`reserved_availability` is in unit of `stock.move` : https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L295

`move.product_qty - move.reserved_availability` seems to have no sens, no ?

https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L915
https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L917
https://github.com/odoo/odoo/blob/11.0/addons/stock/models/stock_move.py#L924

thank for your answer

@jco-odoo 
@alnslang 


'location_id': self.stock_location.id,
            'location_dest_id': self.customer_location.id,
            'product_id': self.product1.id,
            'product_uom': self.uom_unit.id,
            'product_uom_qty': 1.0,
        })
        move1._action_confirm()
        move1._action_assign()
        self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, shelf1_location), 0.0)
        self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, shelf2_location), 0.0)
        self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, self.stock_location), 0.0)
        move1.move_line_ids.location_id = shelf2_location.id
        self.assertEqual(move1.reserved_availability, 0.0)
        self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, self.stock_location), 1.0)
        self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, shelf1_location), 1.0)
        self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, shelf2_location), 0.0)
    def test_edit_reserved_move_line_7(self):
        """ Send 5 tracked products to a client, but these products do not have any lot set in our
        inventory yet: we only set them at delivery time. The created move line should have 5 items
        without any lot set, if we edit to set them to lot1, the reservation should not change.
        Validating the stock move should should not create a negative quant for this lot in stock
        location.
        # """
        lot1 = self.env['stock.production.lot'].create({
            'name': 'lot1',
            'product_id': self.product3.id,
        })
        
        self.env['stock.quant']._update_available_quantity(self.product3, self.stock_location, 5)