From 56919ae45f300e1eebe231fa105547130360db98 Mon Sep 17 00:00:00 2001
From: ehofman <ehofman>
Date: Mon, 4 Jan 2010 14:53:26 +0000
Subject: [PATCH] MacOS returns an unsopported AL error when a file is not
 found, work around this.

---
 simgear/sound/soundmgr_openal.cxx | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/simgear/sound/soundmgr_openal.cxx b/simgear/sound/soundmgr_openal.cxx
index 47b43748..a9db312e 100644
--- a/simgear/sound/soundmgr_openal.cxx
+++ b/simgear/sound/soundmgr_openal.cxx
@@ -573,7 +573,18 @@ bool SGSoundMgr::load(string &samplepath, void **dbuf, int *fmt,
     ALenum error =  alGetError();
     if ( error != AL_NO_ERROR ) {
         string msg = "Failed to load wav file: ";
-        msg.append(alGetString(error));
+        const ALchar *errorString = alGetString(error);
+        if (errorString) {
+            msg.append(errorString);
+        } else {
+            // alGetString returns NULL when an unexpected or OS specific error
+            // occurs: e.g. -43 on Mac when file is not found.
+            // In this case, alGetString() sets 'Invalid Enum' error, so
+            // showing with the original error number is helpful.
+            stringstream ss;
+            ss << alGetString(alGetError()) << "(" << error << ")";
+            msg.append(ss.str());
+        }
         throw sg_io_exception(msg.c_str(), sg_location(samplepath));
         return false;
     }
-- 
2.39.5