From 52eaadc5024c3cd0468141932591099a4399897a Mon Sep 17 00:00:00 2001
From: amylizzle <amylizzle@users.noreply.github.com>
Date: Sat, 25 May 2024 16:55:23 +0100
Subject: [PATCH] can't duplicate in vis_contents

---
 OpenDreamRuntime/Objects/Types/DreamList.cs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/OpenDreamRuntime/Objects/Types/DreamList.cs b/OpenDreamRuntime/Objects/Types/DreamList.cs
index f5527a253e..65df849080 100644
--- a/OpenDreamRuntime/Objects/Types/DreamList.cs
+++ b/OpenDreamRuntime/Objects/Types/DreamList.cs
@@ -823,9 +823,13 @@ public override void SetValue(DreamValue key, DreamValue value, bool allowGrowth
     public override void AddValue(DreamValue value) {
         EntityUid entity;
         if (value.TryGetValueAsDreamObject<DreamObjectMovable>(out var movable)) {
+            if(_visContents.Contains(movable))
+                return; // vis_contents cannot contain duplicates
             _visContents.Add(movable);
             entity = movable.Entity;
         } else if (value.TryGetValueAsDreamObject<DreamObjectTurf>(out var turf)) {
+            if(_visContents.Contains(turf))
+                return; // vis_contents cannot contain duplicates
             _visContents.Add(turf);
             entity = EntityUid.Invalid; // TODO: Support turfs in vis_contents
         } else {