From 9a2fd53f1da0cd36176a53362b6257c3129c3685 Mon Sep 17 00:00:00 2001
From: Kevin Caccamo <kevin@ciinet.org>
Date: Sun, 15 Jun 2025 17:23:48 -0400
Subject: [PATCH] Remove dereferences of comment + 1

If a line ends with a single slash, then you'll get an invalid read
---
 src/gamedata/keysections.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/gamedata/keysections.cpp b/src/gamedata/keysections.cpp
index bdb103a74..ebb1efd28 100644
--- a/src/gamedata/keysections.cpp
+++ b/src/gamedata/keysections.cpp
@@ -197,19 +197,22 @@ void D_LoadWadSettings ()
 			// Comments begin with //
 			char *stop = &command[linePos];
 			char *comment = &command[0];
+			char prevChar = 0;
 			bool inQuote = false;
 
 			while (comment < stop)
 			{
-				// if (*comment != '\\' && *(comment + 1) == '\"')
+				// if (prevChar != '\\' && *comment == '\"')
 				if (*comment == '\"')
 				{
 					inQuote = !inQuote;
 				}
-				else if (!inQuote && *comment == '/' && *(comment + 1) == '/')
+				else if (!inQuote && prevChar == '/' && *comment == '/')
 				{
+					comment--; // 'comment' is on the second slash
 					break;
 				}
+				prevChar = *comment;
 				comment++;
 			}
 			// 'comment' will either be the end of the string, or the starting