Fix code that indexes datum-typed variables

code/_helpers/logging.dm

@@ -201,12 +201,13 @@ var/global/log_end= world.system_type == UNIX ? ascii2text(13) : ""
 	if(isnull(d))
 		return "*null*"
 	if(islist(d))
-		var/list/L = list()
-		for(var/e in d)
+		var/list/out = list()
+		var/list/dlist = d
+		for(var/entry in dlist)
 			// Indexing on numbers just gives us the same number again in the best case and causes an index out of bounds runtime in the worst
-			var/v = isnum(e) ? null : d[e]
-			L += "[log_info_line(e)][" - [log_info_line(v)]"]"
-		return "\[[jointext(L, ", ")]\]" // We format the string ourselves, rather than use json_encode(), because it becomes difficult to read recursively escaped "
+			var/value = isnum(entry) ? null : dlist[entry]
+			out += "[log_info_line(entry)][" - [log_info_line(value)]"]"
+		return "\[[jointext(out, ", ")]\]" // We format the string ourselves, rather than use json_encode(), because it becomes difficult to read recursively escaped "
 	if(!istype(d))
 		return json_encode(d)
 	return d.get_log_info_line()

code/controllers/subsystems/overlays.dm

@@ -113,12 +113,13 @@ SUBSYSTEM_DEF(overlays)
 /atom/proc/build_appearance_list(atom/new_overlays)
 	var/static/image/appearance_bro = new
 	if(islist(new_overlays))
-		if(null in new_overlays)
-			new_overlays -= new /list(length(new_overlays)) // Clears nulls from the list prior to appearancifying.
-		for(var/i in 1 to length(new_overlays))
-			var/image/cached_overlay = new_overlays[i]
-			APPEARANCEIFY(cached_overlay, new_overlays[i])
-		return new_overlays
+		var/list/new_overlays_list = new_overlays
+		if(null in new_overlays_list)
+			new_overlays_list -= new /list(length(new_overlays_list)) // Clears nulls from the list prior to appearancifying.
+		for(var/i in 1 to length(new_overlays_list))
+			var/image/cached_overlay = new_overlays_list[i]
+			APPEARANCEIFY(cached_overlay, new_overlays_list[i])
+		return new_overlays_list
 	else
 		APPEARANCEIFY(new_overlays, .)
 

code/modules/character_info/character_info_interface.dm

@@ -38,10 +38,11 @@
 		return
 
 	if(islist(comments))
-		if(length(comments) == 1)
-			comments = comments[1]
+		var/list/comment_list = comments
+		if(length(comment_list) == 1)
+			comments = comment_list[1]
 		else
-			comments = input(usr, "Multiple matches. Which character do you wish to show?", "View Character Comments") as null|anything in comments
+			comments = input(usr, "Multiple matches. Which character do you wish to show?", "View Character Comments") as null|anything in comment_list
 	if(istype(comments))
 		comments.display_to(usr)
 	else

code/modules/integrated_electronics/core/helpers.dm

@@ -24,9 +24,10 @@
 
 /obj/item/integrated_circuit/proc/set_pin_data(pin_type, pin_number, datum/new_data)
 	if(islist(new_data))
+		var/datum/new_list = new_data
 		for(var/i in 1 to length(new_data))
-			if (istype(new_data) && !isweakref(new_data))
-				new_data[i] = weakref(new_data[i])
+			if (istype(new_list[i], /datum) && !isweakref(new_list[i]))
+				new_data[i] = weakref(new_list[i])
 	if (istype(new_data) && !isweakref(new_data))
 		new_data = weakref(new_data)
 	var/datum/integrated_io/pin = get_pin_ref(pin_type, pin_number)
@@ -62,10 +63,13 @@
 
 /datum/integrated_io/proc/get_data()
 	if(islist(data))
-		for(var/i in 1 to length(data))
-			if(isweakref(data[i]))
-				var/weakref/dw = data[i]
-				data[i] = dw.resolve()
+		var/list/data_list = data
+		data_list = data_list.Copy()
+		for(var/i in 1 to length(data_list))
+			if(isweakref(data_list[i]))
+				var/weakref/dw = data_list[i]
+				data_list[i] = dw.resolve()
+		return data_list
 	if(isweakref(data))
 		return data.resolve()
 	return data

code/modules/mob/mob_helpers.dm

@@ -534,9 +534,9 @@ var/global/list/intents = list(I_HELP,I_DISARM,I_GRAB,I_HURT)
 	return !client && !teleop && (last_ckey || !ai)
 
 /mob/proc/try_teleport(var/area/thearea)
-	if(!istype(thearea))
-		if(istype(thearea, /list))
-			thearea = thearea[1]
+	if(istype(thearea, /list))
+		var/list/area_list = thearea
+		thearea = area_list[1]
 	var/list/L = list()
 	for(var/turf/T in get_area_turfs(thearea))
 		if(!T.density)

code/modules/modular_computers/hardware/nano_printer.dm

@@ -61,13 +61,14 @@
 			if(stored_paper >= max_paper) //check if the printer is full yet
 				to_chat(user, "The printer has been filled to full capacity.")
 				break
-		if(B.pages.len == 0) //if all its papers have been put into the printer, delete bundle
-			qdel(W)
-		else if(B.pages.len == 1) //if only one item left, extract item and delete the one-item bundle
-			user.drop_from_inventory(B)
-			user.put_in_hands(B[1])
-			qdel(B)
-		else //if at least two items remain, just update the bundle icon
-			B.update_icon()
+		switch(length(B.pages))
+			if(0) //if all its papers have been put into the printer, delete bundle
+				qdel(B)
+			if(1) //if only one item left, extract item and delete the one-item bundle
+				user.drop_from_inventory(B)
+				user.put_in_hands(B.pages[1])
+				qdel(B)
+			else //if at least two items remain, just update the bundle icon
+				B.update_icon()
 		to_chat(user, "You add [num_of_pages_added] papers from \the [W] into \the [src].")
 	return

code/modules/spells/general/contract_spells.dm

@@ -27,7 +27,8 @@
 		return null
 
 	if(istype(target,/list))
-		target = target[1]
+		var/list/target_list = target
+		target = target_list[1]
 	return target