GetWeaponType and IsAmmo are not working when being called on reference

[ir4ne]

It's stated in xOBSE documentation that IsAmmo and GetWeaponType can be called on reference. But it seems they only work if weapon reference is passed as an argument.

Steps to reproduce:

1. Register OnHitWith event handler
   SetEventHandler "OnHitWith" MyOnHitWithHandler
2. Write the following in your handler script file:

scn MyOnHitWithHandler

Ref target
Ref weapon

Int weaponType
Int isWeaponAmmo

	
begin Function { target, weapon }

	PrintC "OnHit target %n, weapon %n" target weapon

	let weaponType := weapon.GetWeaponType 
	let isWeaponAmmo := weapon.IsAmmo

	PrintC "weapon %n isAmmo = %g, type = %g" weapon isWeaponAmmo weaponType

end

3. Run the game and hit someone
4. Open your logs, you'll see something like this:

[OnHit target Commoner, weapon Silver Shortsword
Error in script b24cd8c4
Attempting to call a function on a NULL reference or base object: GetWeaponType
    File: IIC_AGFM.esp Offset: 0x0062 Command: GetWeaponType
  Let @0062 script B24CD8C4
Error in script b24cd8c4
Attempting to call a function on a NULL reference or base object: IsAmmo
    File: IIC_AGFM.esp Offset: 0x0079 Command: IsAmmo
  Let @0079 script B24CD8C4
weapon Silver Shortsword isAmmo = 0, type = 0

[llde]

Reflecting a but: this may even not be a bug. In this context weapon is the weapon used to attack, this means that it's in the inventory. Items in inventory doesn't have a reference attached (items that already exist in the word and if I recall correctly are persistent, save their original reference in ExtraData)
So the variable passed to the item is not a reference is a base form, and the error message make perfectly sense.

Maybe I can enhance the event to pass a InventoryReference.