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 


self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, self.supplier_location, allow_negative=True), -100.0)
        self.assertEqual(self.env['stock.quant']._get_available_quantity(self.product1, self.stock_location), 100.0)
        self.assertEqual(len(self.env['stock.quant']._gather(self.product1, self.supplier_location)), 1.0)
        self.assertEqual(len(self.env['stock.quant']._gather(self.product1, self.stock_location)), 1.0)
    def test_in_2(self):
        """ Receive 5 tracked products from a supplier. The create move line should have 5
        reserved. If i assign the 5 items to lot1, the reservation should not change. Once
        i validate, the reception correctly increase a single quant in stock.
        """
        
        move1 = self.env['stock.move'].create({
            'name': 'test_in_1',
            'location_id': self.supplier_location.id,
            'location_dest_id': self.stock_location.id,
            'product_id': self.product3.id,
            'product_uom': self.uom_unit.id,
            'product_uom_qty': 5.0,
            'picking_type_id': self.env.ref('stock.picking_type_in').id,
        })
        self.assertEqual(move1.state, 'draft')
        
        move1._action_confirm()
        self.assertEqual(move1.state, 'confirmed')
        
        move1._action_assign()
        self.assertEqual(move1.state, 'assigned')
        self.assertEqual(len(move1.move_line_ids), 1)
        move_line = move1.move_line_ids[0]
        self.assertEqual(move_line.product_qty, 5)
        move_line.lot_name = 'lot1'