**Impacted versions:** 8.0

**Steps to reproduce:**
To reproduce it is necessary the fifo configuration in the assignation of quants in moves.

- Create a sale order with two lines of the same product, one of that line with a route that generate moves between warehouse.

<img width="1231" alt="skitch 65" src="https://cloud.githubusercontent.com/assets/11341058/24102907/d575a638-0d53-11e7-922e-a3f034d43e94.png">

The route used has three pull rules:

1. From Stock Warehouse_1 to Virtual Locations/Inter Company Transit
2. From Virtual Locations/Inter Company Transit to Stock Warehouse_2
3. From Stock Warehouse_2 to Customers

<img width="1224" alt="skitch 66" src="https://cloud.githubusercontent.com/assets/11341058/24103147/b7c2bfbc-0d54-11e7-955c-87247a10e0bd.png">

- Confirm the sale order. It must be created three pickings:

<img width="1226" alt="skitch 67" src="https://cloud.githubusercontent.com/assets/11341058/24103498/d90c9b38-0d55-11e7-97ff-f986df8cdd9b.png">

- Transfer first two pickings.

<img width="1230" alt="skitch 70" src="https://cloud.githubusercontent.com/assets/11341058/24104496/b7b0be8a-0d58-11e7-89a2-4331fceec1d8.png">

- Before transfer third picking, review that one move has reserved the quant correctly because was reserved from the previous pickings.

<img width="1215" alt="skitch 68" src="https://cloud.githubusercontent.com/assets/11341058/24103908/23952cc8-0d57-11e7-9346-bd48d7edb54a.png">

**Current behavior:**

When check availability of this third picking, the quant already reserved is moved to the other move.

<img width="1264" alt="skitch 69" src="https://cloud.githubusercontent.com/assets/11341058/24104056/8be11616-0d57-11e7-8763-a90507315b19.png">
 
**Expected behavior:**

When check availability of this third picking, the moves already reserved must not be altered.


addons/stock/stock.py
to_solve_quant_ids = self.search(cr, uid, [('propagated_from_id', '=', quant_neg.id)], context=context)
            if not to_solve_quant_ids:
                continue
            solving_qty = qty
            solved_quant_ids = []
            for to_solve_quant in self.browse(cr, uid, to_solve_quant_ids, context=context):
                if float_compare(solving_qty, 0, precision_rounding=product_uom_rounding) <= 0:
                    continue
                solved_quant_ids.append(to_solve_quant.id)
                self._quant_split(cr, uid, to_solve_quant, min(solving_qty, to_solve_quant.qty), context=context)
                solving_qty -= min(solving_qty, to_solve_quant.qty)
            remaining_solving_quant = self._quant_split(cr, uid, solving_quant, qty, context=context)
            remaining_neg_quant = self._quant_split(cr, uid, quant_neg, -qty, context=context)
            
            if remaining_neg_quant:
                remaining_to_solve_quant_ids = self.search(cr, uid, [('propagated_from_id', '=', quant_neg.id), ('id', 'not in', solved_quant_ids)], context=context)
                if remaining_to_solve_quant_ids:
                    self.write(cr, SUPERUSER_ID, remaining_to_solve_quant_ids, {'propagated_from_id': remaining_neg_quant.id}, context=context)
            if solving_quant.propagated_from_id and solved_quant_ids:
                self.write(cr, SUPERUSER_ID, solved_quant_ids, {'propagated_from_id': solving_quant.propagated_from_id.id}, context=context)
            
            self.unlink(cr, SUPERUSER_ID, [quant_neg.id], context=context)
            if solved_quant_ids:
                
                self._price_update(cr, uid, solved_quant_ids, solving_quant.cost, context=context)
                
                self._quants_merge(cr, uid, solved_quant_ids, solving_quant, context=context)
            self.unlink(cr, SUPERUSER_ID, [solving_quant.id], context=context)
            solving_quant = remaining_solving_quant
    def _price_update(self, cr, uid, ids, newprice, context=None):