Infinite Armor Duplication Bug

[TrainStation123]

Game version:
0.C g74036ec

Operating system:
Windows 7 x64

Tiles or curses:
Tiles

Mods active:
(Full List, top to bottom)
-Dark Days Ahead
-Filthy Clothing
-Disable NPC Needs
-Simplified Nutrition
-Bionics Systems Mod
-Makeshift Items Mod
-Icecoon's Arsenal
-More Survival Tools
-Mutant NPCs
-NPC traits
-More Buildings
-Extended Realistic Guns
-Classes and Scenarios Mod
-StatsThroughSkills

Expected behavior

Sort Armor on a friendly NPC to set up clothing/armor.

Actual behavior

Using the Equip armor from inventory (e), causes an error message (no crash). Continuing from error, the NPC is wearing the item, however it is not removed from the player inventory. This is easily exploited to make infinite armor/rags/weapons/etc.

DEBUG : Tried to remove a item in inventory (name: Example)

Function : item inventory::remove_item(const item*)
FILE : src/inventory.ccp
LINE : 525

Steps to reproduce the behavior

• Talk to NPC
• Sort Armor
• Equip armor from inventory (e)
• Give any armor/wearable item to NPC

[ZhilkinSerg]

There is also typo in error message - should be "Tried to remove an item in inventory".

[TrainStation123]

Less of a typo and more of a direct copy.

[ZhilkinSerg]

It was not your typo. Typo is in that message. Article "an" should be used.

[TrainStation123]

Ah, wasn't quite sure what you meant at first.

[CoroNaut]

All because correct grammar is more important the actual bug :D

[ZhilkinSerg]

Spellcheck ftw!

[WhiteRavenPL]

I think the problem is linked to the NOTE here:

Cataclysm-DDA/src/armor_layers.cpp

Lines 516 to 530 in 0ef460d

	} else if( action == "EQUIP_ARMOR" ) {
	// filter inventory for all items that are armor/clothing
	// NOTE: This is from player's inventory, even for NPCs!
	// @todo: Allow making NPCs equip their own stuff
	item_location loc = game_menus::inv::wear( g->u );
	// only equip if something valid selected!
	if( loc ) {
	// wear the item
	if( wear( g->u.i_at( loc.obtain( g->u ) ) ) ) {
	// reorder `worn` vector to place new item at cursor
	auto iter = worn.end();
	item new_equip = *( --iter );
	// remove the item
	worn.erase( iter );

This code is called from within a Character object representing an NPC, but items are taken from g->u which is the player. So the player picks an item from her inventory and then the code tries removing it from the NPCs inventory leading to an error.

Changing the code to use this:

            item_location loc = game_menus::inv::wear( *this );

            // only equip if something valid selected!
            if( loc ) {
                // wear the item
                if( wear( this->i_at( loc.obtain( *this ) ) ) ) {

seems to solve the problem, but then UI messages become inconsistent and keep referencing "you" instead of the NPCs name.