From 2458078987ba94facaa230dc06b7d86a4323a8cf Mon Sep 17 00:00:00 2001
From: Kp <kp@valhallalegends.com>
Date: Sun, 15 Mar 2015 18:52:52 +0000
Subject: [PATCH] Skip digi_sync_sounds loop if !Viewer

If a sound is used, it may dereference Viewer.  If Viewer is null, this
will crash.  In 630f11945e40c856aed0d5ee61b62eb084e6dca9,
digi_sync_sounds changed to assume Viewer is valid.  This crashes during
early startup when not using the SDL_mixer backend, even though no
sounds are in use.

Reported-by: derhass <https://github.com/dxx-rebirth/dxx-rebirth/issues/45>
Fixes: 630f11945e40c856aed0d5ee61b62eb084e6dca9 ("Cache Viewer in digiobj")
---
 similar/main/digiobj.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/similar/main/digiobj.cpp b/similar/main/digiobj.cpp
index 65d8d8733..563474f64 100644
--- a/similar/main/digiobj.cpp
+++ b/similar/main/digiobj.cpp
@@ -530,6 +530,8 @@ void digi_sync_sounds()
 	}
 
 	SoundQ_process();
+	if (!Viewer)
+		return;
 	const vcobjptr_t viewer{Viewer};
 	range_for (auto &s, SoundObjects)
 	{