directly pass the slot number to OpenItemWindow where possible

This prevents problems with "ItemButton" changing in between due to
window focus changes.

gemrb/GUIScripts/InventoryCommon.py

@@ -358,13 +358,18 @@ def DisplayItem (itemresref, type):
 	ItemInfoWindow.ShowModal(MODAL_SHADOW_GRAY)
 	return
 
-def OpenItemInfoWindow ():
+def OpenItemInfoWindow (slot = None):
 	pc = GemRB.GameGetSelectedPCSingle ()
-	if GUICommon.GameIsPST():
-		slot, slot_item = GUIINV.ItemHash[GemRB.GetVar ('ItemButton')]
+
+	if slot == None:
+		if GUICommon.GameIsPST():
+			slot, slot_item = GUIINV.ItemHash[GemRB.GetVar ('ItemButton')]
+		else:
+			slot = GemRB.GetVar ("ItemButton")
+			slot_item = GemRB.GetSlotItem (pc, slot)
 	else:
-		slot = GemRB.GetVar ("ItemButton")
 		slot_item = GemRB.GetSlotItem (pc, slot)
+
 	item = GemRB.GetItem (slot_item["ItemResRef"])
 
 	if TryAutoIdentification(pc, item, slot, slot_item, True):
@@ -790,7 +795,7 @@ def IdentifyUseSpell ():
 		ItemInfoWindow.Unload ()
 	GemRB.ChangeItemFlag (pc, slot, IE_INV_ITEM_IDENTIFIED, OP_OR)
 	GemRB.PlaySound(DEF_IDENTIFY)
-	OpenItemInfoWindow()
+	OpenItemInfoWindow(slot)
 	return
 
 def IdentifyUseScroll ():
@@ -807,7 +812,7 @@ def IdentifyUseScroll ():
 	if GemRB.HasSpecialItem (pc, 1, 1):
 		GemRB.ChangeItemFlag (pc, slot, IE_INV_ITEM_IDENTIFIED, OP_OR)
 	GemRB.PlaySound(DEF_IDENTIFY)
-	OpenItemInfoWindow()
+	OpenItemInfoWindow(slot)
 	return
 
 def CloseIdentifyItemWindow ():