From 45ed69c9f017532a3c29b41e496f71e6f24a8a49 Mon Sep 17 00:00:00 2001
From: Allen Webster <editor@4coder.net>
Date: Sat, 24 Sep 2016 16:58:05 -0400
Subject: [PATCH] Fixed nasty crashing bug in the 4.0.11 branch

---
 4cpp_lexer.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/4cpp_lexer.h b/4cpp_lexer.h
index 1ce4134d..1a96bbe1 100644
--- a/4cpp_lexer.h
+++ b/4cpp_lexer.h
@@ -799,7 +799,7 @@ cpp_lex_nonalloc_null_end_no_limit(Cpp_Lex_Data *S_ptr, char *chunk, int32_t siz
             break;
         }
         
-        if (chunk[S.pos-1] == 0){
+        if (S.pos > S.chunk_pos && chunk[S.pos-1] == 0){
             --S.pos;
         }