From 9ae4e3650c39875bcd1579f421239605e53a31cf Mon Sep 17 00:00:00 2001
From: Menshin <menshin@users.noreply.github.com>
Date: Sat, 13 Sep 2014 00:38:39 +0200
Subject: [PATCH 1/2] * prevented empty stacks from being generated on tiles,
 when merging stacks on floor after crafting them (e.g metal => floor). Fixes
 #4775 * various clean-up of unnecessary checks related to stacks

---
 code/game/objects/items/stacks/stack.dm       | 26 ++++++++++++++-----
 .../objects/items/stacks/tiles/plasteel.dm    |  5 ++--
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/code/game/objects/items/stacks/stack.dm b/code/game/objects/items/stacks/stack.dm
index 80fc7c2ec0b..b968b86039a 100644
--- a/code/game/objects/items/stacks/stack.dm
+++ b/code/game/objects/items/stacks/stack.dm
@@ -135,23 +135,32 @@
 			usr << "<span class='notice'>Building [R.title] ...</span>"
 			if (!do_after(usr, R.time))
 				return
-		if (src.get_amount() < R.req_amount*multiplier)
-			return
+			if (src.get_amount() < R.req_amount*multiplier)
+				return
+
 		var/atom/O = new R.result_type( usr.loc )
 		O.dir = usr.dir
+		use(R.req_amount * multiplier)
+
+		//is it a stack ?
 		if (R.max_res_amount > 1)
 			var/obj/item/stack/new_item = O
 			new_item.amount = R.res_amount*multiplier
-			new_item.add_to_stacks(usr)
-		use(R.req_amount * multiplier)
+			new_item.add_to_stacks(usr) //try to merge with existing stacks on current tile
+
+			if(new_item.amount <= 0)//if the stack is empty, i.e it has been merged with an existing stack and has been garbage collected
+				return
+
 		if (istype(O,/obj/item))
 			usr.put_in_hands(O)
 		O.add_fingerprint(usr)
+
 		//BubbleWrap - so newly formed boxes are empty
 		if ( istype(O, /obj/item/weapon/storage) )
 			for (var/obj/item/I in O)
 				qdel(I)
 		//BubbleWrap END
+
 	if (src && usr.machine==src) //do not reopen closed window
 		spawn( 0 )
 			src.interact(usr)
@@ -167,6 +176,7 @@
 	if (amount <= 0)
 		if(usr)
 			usr.unEquip(src, 1)
+		src.loc = null
 		qdel(src)
 	return 1
 
@@ -188,7 +198,7 @@
 			continue
 		oldsrc.attackby(item, usr)
 		usr << "You add new [item.singular_name] to the stack. It now contains [item.amount] [item.singular_name]\s."
-		if(!oldsrc)
+		if(oldsrc.amount <= 0)
 			break
 
 /obj/item/stack/attack_hand(mob/user as mob)
@@ -206,7 +216,7 @@
 	return
 
 /obj/item/stack/attackby(obj/item/W as obj, mob/user as mob)
-	..()
+
 	if (istype(W, src.type))
 		var/obj/item/stack/S = W
 		if (S.is_cyborg)
@@ -231,7 +241,9 @@
 			src.use(to_transfer)
 			if (src && usr.machine==src)
 				spawn(0) src.interact(usr)
-	else return ..()
+
+	else
+		..()
 
 /obj/item/stack/proc/copy_evidences(obj/item/stack/from as obj)
 	src.blood_DNA = from.blood_DNA
diff --git a/code/game/objects/items/stacks/tiles/plasteel.dm b/code/game/objects/items/stacks/tiles/plasteel.dm
index a76a3e35da4..5e922c9a6c5 100644
--- a/code/game/objects/items/stacks/tiles/plasteel.dm
+++ b/code/game/objects/items/stacks/tiles/plasteel.dm
@@ -25,7 +25,7 @@
 	return
 
 /obj/item/stack/tile/plasteel/attackby(obj/item/W as obj, mob/user as mob)
-	..()
+
 	if (istype(W, /obj/item/weapon/weldingtool))
 		var/obj/item/weapon/weldingtool/WT = W
 
@@ -45,7 +45,8 @@
 			if (!R && replace)
 				user.put_in_hands(new_item)
 		return
-	..()
+	else
+		..()
 
 /*
 /obj/item/stack/tile/plasteel/attack_self(mob/user as mob)

From abda57bc2612ef0fc35ba8096582e9612630c563 Mon Sep 17 00:00:00 2001
From: Menshin <menshin@users.noreply.github.com>
Date: Sun, 14 Sep 2014 11:51:02 +0200
Subject: [PATCH 2/2] Location nulling moved to Destroy() proc

---
 code/game/objects/items/stacks/stack.dm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/game/objects/items/stacks/stack.dm b/code/game/objects/items/stacks/stack.dm
index b968b86039a..9921a1ea472 100644
--- a/code/game/objects/items/stacks/stack.dm
+++ b/code/game/objects/items/stacks/stack.dm
@@ -29,6 +29,7 @@
 		return // Not supposed to be destroyed
 	if (usr && usr.machine==src)
 		usr << browse(null, "window=stack")
+	src.loc = null
 	..()
 
 /obj/item/stack/examine()
@@ -176,7 +177,6 @@
 	if (amount <= 0)
 		if(usr)
 			usr.unEquip(src, 1)
-		src.loc = null
 		qdel(src)
 	return 1