Fix "INVITE with Replaces header" deadlock

This occurs on reception of an INVITE with a Replaces header, due to the
following path:

- recvd_invite() acquires a read lock on lines_mtx
- recvd_initial_invite() is called
- A write lock over lines_mtx is acquired

1 files changed, 1 insertions, 1 deletions

diff --git a/src/phone.cpp b/src/phone.cpp
index 8de3834..a609bef 100644
--- a/src/phone.cpp
+++ b/src/phone.cpp
@@ -905,7 +905,7 @@ void t_phone::post_process_response(t_response *r, t_tuid tuid, t_tid tid) {
 }
 
 void t_phone::recvd_invite(t_request *r, t_tid tid) {
-	t_rwmutex_reader x(lines_mtx);
+	t_rwmutex_future_writer x(lines_mtx);
 
 	// Check if this INVITE is a retransmission.
 	// Once the TU sent a 2XX repsonse on an INVITE it has to deal