From 5db1f95b293385a5219482524615fefa03f05e62 Mon Sep 17 00:00:00 2001
From: nukeykt <alexeytf2@icloud.com>
Date: Sun, 26 Jan 2020 22:26:08 +0900
Subject: [PATCH] Prevent OOB issues in old pushmove

---
 source/build/src/clip.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/source/build/src/clip.cpp b/source/build/src/clip.cpp
index 34e224e19..45ae15fe4 100644
--- a/source/build/src/clip.cpp
+++ b/source/build/src/clip.cpp
@@ -1562,6 +1562,8 @@ int pushmove(vec3_t *const vect, int16_t *const sectnum,
 
         if (clear)
         {
+            if (enginecompatibility_mode != ENGINECOMPATIBILITY_NONE && *sectnum < 0)
+                return 0;
             clipsectorlist[0] = *sectnum;
             clipsectnum = 1;