From e4de85c4f5dc83b9448cb8fcf399301f87a216f9 Mon Sep 17 00:00:00 2001
From: Joshua Colp <jcolp@digium.com>
Date: Sat, 13 Jan 2007 06:00:24 +0000
Subject: [PATCH] Only write a frame out to the channel if one exists. There
 are cases where one may not and would therefore cause the channel driver to
 segfault. (issue #8434 reported by slimey)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@50727 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 main/channel.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/main/channel.c b/main/channel.c
index e895d27831..1dd1e0c74e 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -2650,8 +2650,10 @@ int ast_write(struct ast_channel *chan, struct ast_frame *fr)
 			/* and now put it through the regular translator */
 			f = (chan->writetrans) ? ast_translate(chan->writetrans, f, 0) : f;
 		}
-		
-		res = chan->tech->write(chan, f);
+		if (f)
+			res = chan->tech->write(chan, f);
+		else
+			res = 0;
 		break;
 	case AST_FRAME_NULL:
 	case AST_FRAME_IAX: