From 9f809839759abadab8c0e6f1cff8acd44cf8ea19 Mon Sep 17 00:00:00 2001
From: Garux <garux@mail.ru>
Date: Fri, 22 Feb 2019 23:55:20 +0300
Subject: [PATCH] prevent buffer underflow in Vector4ClipPolygon

---
 libs/math/frustum.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libs/math/frustum.h b/libs/math/frustum.h
index 08990aec..eb635d5e 100644
--- a/libs/math/frustum.h
+++ b/libs/math/frustum.h
@@ -96,6 +96,8 @@ typedef Vector4* iterator;
 typedef const Vector4* const_iterator;
 
 static std::size_t apply( const_iterator first, const_iterator last, iterator out ){
+	if( first == last ) /* prevent buffer underflow in compare( *i ); isn't actually required, for technical correctness only */
+		return 0;
 	const_iterator next = first, i = last - 1;
 	iterator tmp( out );
 	bool b0 = ClipPlane::compare( *i );