From 758327f4b3c560ef8cf678d1040c4133f7c96f58 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Fri, 5 Mar 2010 03:11:10 +0000
Subject: [PATCH] - Fixed: snd_musicvolume needs to check GSnd for NULL, since
 somebody might have set an   atexit for it, which gets executed after the
 sound system shuts down. - Fixed: FPlayList::Backup() failed to wrap around
 below entry 0 because Position is   unsigned now.

SVN r2188 (trunk)
---
 src/s_playlist.cpp    | 2 +-
 src/sound/i_music.cpp | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/s_playlist.cpp b/src/s_playlist.cpp
index 1ab294dc1..e92a5ceea 100644
--- a/src/s_playlist.cpp
+++ b/src/s_playlist.cpp
@@ -198,7 +198,7 @@ int FPlayList::Advance ()
 
 int FPlayList::Backup ()
 {
-	if (--Position < 0)
+	if (Position-- == 0)
 	{
 		Position = Songs.Size() - 1;
 	}
diff --git a/src/sound/i_music.cpp b/src/sound/i_music.cpp
index 83c75410d..38e820c8b 100644
--- a/src/sound/i_music.cpp
+++ b/src/sound/i_music.cpp
@@ -112,7 +112,10 @@ CUSTOM_CVAR (Float, snd_musicvolume, 0.5f, CVAR_ARCHIVE|CVAR_GLOBALCONFIG)
 	else
 	{
 		// Set general music volume.
-		GSnd->SetMusicVolume(clamp<float>(self * relative_volume, 0, 1));
+		if (GSnd != NULL)
+		{
+			GSnd->SetMusicVolume(clamp<float>(self * relative_volume, 0, 1));
+		}
 		// For music not implemented through the digital sound system,
 		// let them know about the change.
 		if (currSong != NULL)