Cope more gracefully when we can't access the sound device.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4070 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/openal/Sound.java

@@ -176,6 +176,11 @@ public class Sound
     protected boolean play (
         boolean allowDefer, final boolean loop, final StartObserver obs)
     {
+        // if we were unable to get our buffer, fail immediately
+        if (_buffer == null) {
+            return false;
+        }
+
         // if we're not ready to go...
         if (!_buffer.isPlayable()) {
             if (allowDefer) {

src/java/com/threerings/openal/SoundGroup.java

@@ -62,7 +62,10 @@ public class SoundGroup
      */
     public void dispose ()
     {
-        AL10.alDeleteSources(_sourceIds);
+        if (_sourceIds != null) {
+            AL10.alDeleteSources(_sourceIds);
+            _sourceIds = null;
+        }
     }
 
     protected SoundGroup (
@@ -84,6 +87,7 @@ public class SoundGroup
         if (errno != AL10.AL_NO_ERROR) {
             Log.warning("Failed to create sources [cprov=" + provider +
                         ", sources=" + sources + ", errno=" + errno + "].");
+            _sourceIds = null;
             // we'll have no sources which means all requests to play
             // sounds will silently fail as if all sources were in use