Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 333499)
+++ channels/chan_sip.c	(working copy)
@@ -6091,7 +6091,7 @@
 
 	if (!p) {
 		ast_debug(1, "Asked to hangup channel that was not connected\n");
-		return 0;
+		return -1;
 	}
 	if (ast_test_flag(ast, AST_FLAG_ANSWERED_ELSEWHERE) || ast->hangupcause == AST_CAUSE_ANSWERED_ELSEWHERE) {
 		ast_debug(1, "This call was answered elsewhere");
Index: main/channel.c
===================================================================
--- main/channel.c	(revision 333499)
+++ main/channel.c	(working copy)
@@ -6480,6 +6480,9 @@
 	/* Start by disconnecting the original's physical side */
 	if (clonechan->tech->hangup && clonechan->tech->hangup(clonechan)) {
 		ast_log(LOG_WARNING, "Hangup failed!  Strange things may happen!\n");
+		ast_channel_unlock(clonechan);
+		ast_hangup(clonechan);
+		clonechan = NULL;
 		res = -1;
 		goto done;
 	}
Index: main/features.c
===================================================================
--- main/features.c	(revision 333499)
+++ main/features.c	(working copy)
@@ -6925,7 +6925,7 @@
 
 int ast_can_pickup(struct ast_channel *chan)
 {
-	if (!chan->pbx && !chan->masq && !ast_test_flag(chan, AST_FLAG_ZOMBIE)
+	if (chan->tech_pvt && !chan->pbx && !chan->masq && !ast_test_flag(chan, AST_FLAG_ZOMBIE)
 		&& (chan->_state == AST_STATE_RINGING
 			|| chan->_state == AST_STATE_RING
 			/*