[FIX] stock: unreserve move only if reserved quants

An issue occurs in the following use case:
- Enable "Bring goods to output location before shipping (Pick + Ship)"
- Create a SO with 2 lines. 2 Deliveries are created, Pack and Ship.
- Go to "Procurement Exceptions", and cancel one of the 2 lines
- Go to the OUTgoing shipping, "Force Availability", and "Validate"

An error occurs: "Cannot unreserve a done move". The system tries to
unreserve a move which is actually cancelled.

Actually, it should not be necessary to unreserve this move, since no
quants were actually reserved in a first place. The fix ensures that, in
this situation, we don't try to unreserve a move with no quant reserved.
This should be safe to do it in all cases, but better be safe by adding
the condition `if 'no_state_change' in context` to impact only this
specific use case.

opw-685650

addons/stock/stock.py

@@ -1554,12 +1554,18 @@ class stock_picking(models.Model):
 
     def rereserve_quants(self, cr, uid, picking, move_ids=[], context=None):
         """ Unreserve quants then try to reassign quants."""
+        if context is None:
+            context = {}
         stock_move_obj = self.pool.get('stock.move')
         if not move_ids:
             self.do_unreserve(cr, uid, [picking.id], context=context)
             self.action_assign(cr, uid, [picking.id], context=context)
         else:
-            stock_move_obj.do_unreserve(cr, uid, move_ids, context=context)
+            if 'no_state_change' in context:
+                move = stock_move_obj.browse(cr, uid, move_ids, context=context)
+                stock_move_obj.do_unreserve(cr, uid, [m.id for m in move if m.reserved_quant_ids], context=context)
+            else:
+                stock_move_obj.do_unreserve(cr, uid, move_ids, context=context)
             stock_move_obj.action_assign(cr, uid, move_ids, no_prepare=True, context=context)
 
     def do_new_transfer(self, cr, uid, ids, context=None):