Index: main/channel.c
===================================================================
--- main/channel.c	(revision 45159)
+++ main/channel.c	(working copy)
@@ -2611,7 +2611,10 @@
 		res = 0;
 		break;
 	default:
-		res = chan->tech->write(chan, f);
+		/* At this point, fr is the incoming frame and f is NULL.  Channels do
+		 * not expect to get NULL as a frame pointer and will segfault.  Hence,
+		 * we output the original frame passed in. */
+		res = chan->tech->write(chan, fr);
 		break;
 	}