Fix posibly forged layer and different layer during equip trigger (#1391)

[mtwango]

• add check for real and sent layer in PacketItemEquipReq (with debug info)
• swap real layer during ItemEquip withing EquipTest / ItemEquipTest trigger

[cbnolok]

Would you mind to explain the issues (maybe just the second one) in a dedicated changelog entry?

[mtwango]

Added changelog entry.

I'll try to elaborate here:

When player dclicks object (Packet 0x06) the workflow for equipping items works roughly this way:

PacketDoubleClick::onReceive ->
CClient::Event_DoubleClick ->
CClient::Cmd_Use_Item ->
CChar::ItemEquip

And the object id is found by uid.ObjFind() (uid is sent by client).

During equipping via dragging to paperdoll or dress macro (Packet 0x13), its like this:

PacketItemEquipReq::onReceive ->
CChar::ItemEquip

In PacketItemEquipReq::onReceive we are finding object id by checking it in LAYER_DRAGGING source->LayerFind(LAYER_DRAGGING) and comparing it to id sent by client. The dragged object has modified layer, since it is currently 'equipped' there. But the EquipTest trigger had this modified layer instead of real / defined one (where it is going to be).

The actual layer during equipping is changed in LayerAdd(pItem, layer);, but it was after the EquipTest trigger.,

I'm pretty sure, this is very specific behaviour and it could have been worked around by numerous ways (ie using findlayer / findid), but it should unify the equiping behaviour.