File 0001-ac3dec-Show-usage-if-no-parameter-is-passed.patch of Package alsa-tools

From 848e26d10e5d11e33727c318bd2f9eb5cf93e67f Mon Sep 17 00:00:00 2001
From: Fabio Estevam <fabio.estevam@freescale.com>
Date: Tue, 13 Nov 2012 10:08:14 -0200
Subject: [PATCH 1/3] ac3dec: Show usage if no parameter is passed

When ac3dec is called without any argument the application hangs forever.

Instead of hanging, print the usage and exit.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 ac3dec/ac3dec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ac3dec/ac3dec.c b/ac3dec/ac3dec.c
index 00c4f1a..89d7ce8 100644
--- a/ac3dec/ac3dec.c
+++ b/ac3dec/ac3dec.c
@@ -130,6 +130,11 @@ int main(int argc,char *argv[])
 	out_config.spdif = SPDIF_NONE;
 	out_config.hdmi = 0;
 
+	if (isatty(fileno(stdin)) && (argc == 1)) {
+		help();
+		return 1;
+	}
+
 	morehelp = 0;
 	while (1) {
 		int c;
-- 
1.8.0.1