From 97859fd60872324609e32316c54bcc451d22d484 Mon Sep 17 00:00:00 2001
From: Xaser Acheron <xaser@angryscience.net>
Date: Tue, 11 Jan 2022 10:55:34 -0600
Subject: [PATCH] fix MBF21 GetSoundArg off-by-one: sound indices are 1-indexed
 in args because Killough

---
 src/gamedata/d_dehacked.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/gamedata/d_dehacked.cpp b/src/gamedata/d_dehacked.cpp
index f12a0fcdf..fa744e63b 100644
--- a/src/gamedata/d_dehacked.cpp
+++ b/src/gamedata/d_dehacked.cpp
@@ -184,7 +184,7 @@ struct MBFParamState
 	int GetSoundArg(int i, int def = 0)
 	{
 		int num = argsused & (1 << i) ? (int)args[i] : def;
-		if (num > 0 && num < int(SoundMap.Size())) return SoundMap[num];
+		if (num > 0 && num <= int(SoundMap.Size())) return SoundMap[num-1];
 		return 0;
 	}