From a7ff9478a7d45a0734c91f2980223ebba2524ce7 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@users.noreply.github.com>
Date: Wed, 22 Apr 2015 20:28:09 -0500
Subject: [PATCH] Fixed: S_PrecacheLevel() could create orphan channels

- S_PrecacheLevel() must also mark currently playing sounds as
  used. If we don't, the sound could be unloaded and the underlying
  channel stopped without triggering a channel callback. That would leave
  the code in s_sound.cpp thinking the sound is still playing even though
  it isn't.
- Added an invalid channel check to FMODSoundRenderer::StopChannel() so
  that orphan channels passed to it will be returned at least when
  S_StopAllChannels() is called.
---
 src/s_sound.cpp         | 13 ++++++-------
 src/sound/fmodsound.cpp |  7 +++++--
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/s_sound.cpp b/src/s_sound.cpp
index 5b3d5457b..7b543c4e4 100644
--- a/src/s_sound.cpp
+++ b/src/s_sound.cpp
@@ -383,7 +383,7 @@ void S_Start ()
 	{
 		// kill all playing sounds at start of level (trust me - a good idea)
 		S_StopAllChannels();
-		
+
 		// Check for local sound definitions. Only reload if they differ
 		// from the previous ones.
 		FString LocalSndInfo;
@@ -487,6 +487,11 @@ void S_PrecacheLevel ()
 		{
 			level.info->PrecacheSounds[i].MarkUsed();
 		}
+		// Don't unload sounds that are playing right now.
+		for (FSoundChan *chan = Channels; chan != NULL; chan = chan->NextChan)
+		{
+			chan->SoundID.MarkUsed();
+		}
 
 		for (i = 1; i < S_sfx.Size(); ++i)
 		{
@@ -2083,12 +2088,6 @@ void S_ChannelEnded(FISoundChannel *ichan)
 				evicted = (pos < len);
 			}
 		}
-		/*
-		else
-		{
-			evicted = false;
-		}
-		*/
 		if (!evicted)
 		{
 			S_ReturnChannel(schan);
diff --git a/src/sound/fmodsound.cpp b/src/sound/fmodsound.cpp
index 1739556b4..269720c48 100644
--- a/src/sound/fmodsound.cpp
+++ b/src/sound/fmodsound.cpp
@@ -2050,7 +2050,7 @@ FISoundChannel *FMODSoundRenderer::CommonChannelSetup(FMOD::Channel *chan, FISou
 
 //==========================================================================
 //
-// FMODSoundRenderer :: StopSound
+// FMODSoundRenderer :: StopChannel
 //
 //==========================================================================
 
@@ -2058,7 +2058,10 @@ void FMODSoundRenderer::StopChannel(FISoundChannel *chan)
 {
 	if (chan != NULL && chan->SysChannel != NULL)
 	{
-		((FMOD::Channel *)chan->SysChannel)->stop();
+		if (((FMOD::Channel *)chan->SysChannel)->stop() == FMOD_ERR_INVALID_HANDLE)
+		{ // The channel handle was invalid; pretend it ended.
+			S_ChannelEnded(chan);
+		}
 	}
 }