From 983e8bc6a5714f0d317d2458f8346c6d6c01a98c Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <c.oelckers@zdoom.fake>
Date: Sat, 5 Mar 2016 22:39:53 +0100
Subject: [PATCH] - explicitly check NAME_Null in P_FindTerrain so that it
 cannot get rendered inoperable by mods which hijack this name. This name must
 be reserved so that there is some means to disable a sector's terrain.

---
 src/p_terrain.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/p_terrain.cpp b/src/p_terrain.cpp
index 37c2bda0e..3c6519393 100644
--- a/src/p_terrain.cpp
+++ b/src/p_terrain.cpp
@@ -702,6 +702,7 @@ int P_FindTerrain (FName name)
 {
 	unsigned int i;
 
+	if (name == NAME_Null) return -1;
 	for (i = 0; i < Terrains.Size (); i++)
 	{
 		if (Terrains[i].Name == name)