From 72e4729ad5aa390aa8aa5c57c53f0bd3faf666b8 Mon Sep 17 00:00:00 2001
From: Russell Bryant <russell@russellbryant.com>
Date: Mon, 10 Mar 2008 16:58:57 +0000
Subject: [PATCH] Fix a race condition where the generator can go away (closes
 issue #12175, reported by edantie, patched by me)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@107099 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 main/channel.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/main/channel.c b/main/channel.c
index 2cb3b7be38..d148cd97d5 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -1560,9 +1560,13 @@ static int generator_force(const void *data)
 	ast_channel_lock(chan);
 	tmp = chan->generatordata;
 	chan->generatordata = NULL;
-	generate = chan->generator->generate;
+	if (chan->generator)
+		generate = chan->generator->generate;
 	ast_channel_unlock(chan);
 
+	if (!tmp || !generate)
+		return 0;
+
 	res = generate(chan, tmp, 0, 160);
 
 	chan->generatordata = tmp;