Act more gracefully when failing to load a (VOC) sound (should help bug #889442)

svn-id: r12719

scumm/sound.cpp

@@ -830,6 +830,11 @@ void Sound::startSfxSound(File *file, int file_size, PlayingSoundHandle *handle,
 	} else {
 		input = makeVOCStream(_sfxFile);
 	}
+	
+	if (!input) {
+		warning("startSfxSound failed to load sound");
+		return 0;
+	}
 
 	if (_vm->_imuseDigital) {
 		//_vm->_imuseDigital->stopSound(kTalkSoundID);

sound/voc.cpp

@@ -156,6 +156,9 @@ AudioStream *makeVOCStream(byte *ptr) {
 	int size, rate, loops;
 	byte *data = readVOCFromMemory(ptr, size, rate, loops);
 
+	if (!data)
+		return 0;
+
 	return makeLinearInputStream(rate, SoundMixer::FLAG_AUTOFREE | SoundMixer::FLAG_UNSIGNED, data, size, 0, 0);
 }
 
@@ -163,6 +166,9 @@ AudioStream *makeVOCStream(File *file) {
 	int size, rate;
 	byte *data = loadVOCFile(file, size, rate);
 
+	if (!data)
+		return 0;
+
 	return makeLinearInputStream(rate, SoundMixer::FLAG_AUTOFREE | SoundMixer::FLAG_UNSIGNED, data, size, 0, 0);
 }