From e6854d61aad5ffdc9ec6a4f65a3d3e91ce6c38d2 Mon Sep 17 00:00:00 2001
From: Kano <89972582+kano-dot@users.noreply.github.com>
Date: Sun, 25 Jan 2026 21:04:01 +0300
Subject: [PATCH] Fixes lattice duplicate check (#21740)

---
 code/game/objects/structures/lattice.dm           | 9 +--------
 html/changelogs/kano-dot-schrodingers-lattice.yml | 6 ++++++
 2 files changed, 7 insertions(+), 8 deletions(-)
 create mode 100644 html/changelogs/kano-dot-schrodingers-lattice.yml

diff --git a/code/game/objects/structures/lattice.dm b/code/game/objects/structures/lattice.dm
index 3a2b1f782bd..a10f12f0978 100644
--- a/code/game/objects/structures/lattice.dm
+++ b/code/game/objects/structures/lattice.dm
@@ -59,7 +59,7 @@
 
 /obj/structure/lattice/proc/check_for_duplicates()
 	for(var/obj/structure/lattice/found_lattice in get_turf(src))
-		if(found_lattice == src || istype(found_lattice, /obj/structure/lattice/ceiling))
+		if(found_lattice == src || found_lattice.type != src.type) // if the instance we're comparing is us or a different type, then it's not a duplicate
 			continue
 		return TRUE
 	return FALSE
@@ -99,13 +99,6 @@
 	. = ..()
 	AddComponent(/datum/component/large_transparency, 0, 0, 0, 0)
 
-/obj/structure/lattice/ceiling/check_for_duplicates()
-	for(var/obj/structure/lattice/ceiling/found_lattice in get_turf(src))
-		if(found_lattice == src)
-			continue
-		return TRUE
-	return FALSE
-
 /obj/structure/lattice/catwalk
 	name = "catwalk"
 	desc = "A catwalk for easier EVA maneuvering."
diff --git a/html/changelogs/kano-dot-schrodingers-lattice.yml b/html/changelogs/kano-dot-schrodingers-lattice.yml
new file mode 100644
index 00000000000..293554ea2c1
--- /dev/null
+++ b/html/changelogs/kano-dot-schrodingers-lattice.yml
@@ -0,0 +1,6 @@
+author: Kano
+
+delete-after: True
+
+changes:
+  - bugfix: "Fixed an issue pertinent to lattice duplicate check, which was causing issues in away_site_testing checks."