[MIRROR] Assorted Fixes

code/modules/overmap/ships/computers/ship.dm

@@ -112,16 +112,19 @@ somewhere on that shuttle. Subtypes of these can be then used to perform ship ov
 		return 0
 
 /obj/machinery/computer/ship/Destroy()
-	linked.consoles -= src
+	if (linked)
+		linked.consoles -= src
 	. = ..()
 
 /obj/machinery/computer/ship/sensors/Destroy()
-	var/obj/machinery/shipsensors/sensor = sensor_ref.resolve()
-	LAZYREMOVE(sensor.linked_consoles, src)
-	sensor_ref = null
-	if(LAZYLEN(viewers))
+	if (sensor_ref)
+		var/obj/machinery/shipsensors/sensor = sensor_ref.resolve()
+		LAZYREMOVE(sensor.linked_consoles, src)
+		sensor_ref = null
+
+	if (LAZYLEN(viewers))
 		for(var/weakref/W in viewers)
 			var/M = W.resolve()
-			if(M)
+			if (M)
 				unlook(M)
 	. = ..()

code/modules/power/apc.dm

@@ -551,8 +551,8 @@
 			to_chat(user, SPAN_WARNING("The wire connection is in the way."))
 			return TRUE
 		var/obj/item/weldingtool/WT = W
-		if (WT.can_use(3, user))
-			return
+		if (!WT.can_use(3, user))
+			return TRUE
 		user.visible_message(SPAN_WARNING("\The [user] begins to weld \the [src]."), \
 							"You start welding the APC frame...", \
 							"You hear welding.")

maps/torch/structures/signs.dm

@@ -49,13 +49,13 @@
 /obj/structure/sign/memorial/use_tool(obj/item/tool, mob/user, list/click_params)
 	// Dog Tags - Add dog tag
 	if (istype(tool, /obj/item/clothing/accessory/badge/solgov/tags))
-		if (!user.unEquip(tool, src))
-			FEEDBACK_UNEQUIP_FAILURE(user, tool)
-			return TRUE
 		var/obj/item/clothing/accessory/badge/solgov/tags/dog_tags = tool
 		if (!(dog_tags.owner_branch in accepted_branches))
 			USE_FEEDBACK_FAILURE("\The [src] only accepts dog tags from the [english_list(accepted_branches, and_text = " or ")] branches.")
 			return TRUE
+		if (!user.unEquip(tool, src))
+			FEEDBACK_UNEQUIP_FAILURE(user, tool)
+			return TRUE
 		fallen += "[dog_tags.owner_rank] [dog_tags.owner_name] | [dog_tags.owner_branch]"
 		user.visible_message(
 			SPAN_NOTICE("\The [user] adds \a [tool] to \the [src]."),