From 3f4ba9f3880dfbc2a2f86303dc085c09e35790b2 Mon Sep 17 00:00:00 2001
From: Roman Fomin <rfomin@gmail.com>
Date: Thu, 13 Apr 2023 06:36:08 +0700
Subject: [PATCH] check for negative value in ptr_lstrip() (#988)

* check for negative value in ptr_lstrip()

This fixes parsing of DEHACKED in D2ISOv2.wad with debug version of CRT. If the
value < 0 the behavior of `isspace()` is undefined according to the
documentation.

* disable vcpkg update
---
 src/d_deh.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/d_deh.c b/src/d_deh.c
index a34743e2..9bfa451f 100644
--- a/src/d_deh.c
+++ b/src/d_deh.c
@@ -3137,7 +3137,7 @@ void rstrip(char *s)  // strip trailing whitespace
 //
 char *ptr_lstrip(char *p)  // point past leading whitespace
 {
-  while (isspace(*p))
+  while (*p >= 0 && isspace(*p))
     p++;
   return p;
 }