Fix niche interaction with nested inventory deleting items (#1203)

* fix inventory bug

* tick unit test

* fix

* HECK

* i hate this game

* hud garbo

* ghh

Author: Kapu1178

code/_onclick/hud/hud.dm

@@ -193,6 +193,7 @@ GLOBAL_LIST_INIT(available_ui_styles, list(
 /mob/proc/create_mob_hud()
 	if(!client || hud_used)
 		return
+
 	set_hud_used(new hud_type(src))
 	update_sight()
 	SEND_SIGNAL(src, COMSIG_MOB_HUD_CREATED)

code/modules/mob/inventory.dm

@@ -305,17 +305,7 @@
 		. |= dropItemToGround(I)
 
 /mob/proc/putItemFromInventoryInHandIfPossible(obj/item/I, hand_index, force_removal = FALSE, use_unequip_delay = FALSE)
-	if(!can_put_in_hand(I, hand_index))
-		return FALSE
-	if(!temporarilyRemoveItemFromInventory(I, force_removal, use_unequip_delay = use_unequip_delay))
-		return FALSE
-
-	I.remove_item_from_storage(src)
-
-	if(!pickup_item(I, hand_index, ignore_anim = TRUE))
-		qdel(I)
-		CRASH("Assertion failure: putItemFromInventoryInHandIfPossible") //should never be possible
-	return TRUE
+	return pickup_item(I, hand_index, ignore_anim = TRUE)
 
 /// Switches the items inside of two hand indexes.
 /mob/proc/swapHeldIndexes(index_A, index_B)
@@ -414,6 +404,9 @@
 	if(!I) //If there's nothing to drop, the drop is automatically succesfull. If(unEquip) should generally be used to check for TRAIT_NODROP.
 		return TRUE
 
+	if(I.equipped_to != src) // It isn't even equipped to us.
+		return TRUE
+
 	if(!force && !canUnequipItem(I, newloc, no_move, invdrop, silent))
 		return FALSE
 

code/modules/unit_tests/combat/__include.dm

@@ -6,5 +6,6 @@
 #include "combat_door_click.dm"
 #include "combat_emp_flashlight.dm"
 #include "combat_flash.dm"
+#include "combat_nested_inventory.dm"
 #include "combat_pistol_whip.dm"
 #include "combat_stamina.dm"

code/modules/unit_tests/combat/combat_nested_inventory.dm

@@ -0,0 +1,19 @@
+/datum/unit_test/nested_inventory
+	name = "COMBAT/INTERACTION: Clikc-Dragging Nested Inventory Shall Not Delete Items"
+
+/datum/unit_test/nested_inventory/Run()
+	var/mob/living/carbon/human/consistent/user = ALLOCATE_BOTTOM_LEFT()
+	var/obj/item/storage/backpack/backpack = ALLOCATE_BOTTOM_LEFT()
+	var/obj/item/storage/box/survival/box = ALLOCATE_BOTTOM_LEFT()
+
+	box.forceMove(backpack)
+	user.equip_to_slot_if_possible(backpack, ITEM_SLOT_BACK)
+
+	TEST_ASSERT(user.get_item_by_slot(ITEM_SLOT_BACK) == backpack, "Mob did not equip the backpack.")
+
+	var/obj/item/nested_item = box.contents[1]
+	user.putItemFromInventoryInHandIfPossible(nested_item, user.active_hand_index)
+
+	TEST_ASSERT(!user.is_holding(nested_item), "Mob equipped the item.")
+	TEST_ASSERT(!QDELETED(nested_item), "Item was qdeleted.")
+	TEST_ASSERT(nested_item.loc == box, "Item ended up outside the box, inside [nested_item.loc || "NULLSPACE"].")