From 26532364bbd2e591f9dcc2a28b0eb22a88a90472 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Mon, 18 Apr 2016 21:55:50 +0200
Subject: [PATCH] fix possible crash at session close.

In the wake of 81faa3b420303eec2ca0e3. Disconnect Signal from process
callback, may notify an IO that just reached a zero shared ptr refcount
due to route-deletion (GUI thread) resulting in a double free.
---
 libs/ardour/io.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libs/ardour/io.cc b/libs/ardour/io.cc
index 3bbe34f825..87bac6b8f4 100644
--- a/libs/ardour/io.cc
+++ b/libs/ardour/io.cc
@@ -99,6 +99,9 @@ IO::~IO ()
 void
 IO::disconnect_check (boost::shared_ptr<Port> a, boost::shared_ptr<Port> b)
 {
+	if (_session.state_of_the_state () & Session::Deletion) {
+		return;
+	}
 	/* this could be called from within our own ::disconnect() method(s)
 	   or from somewhere that operates directly on a port. so, we don't
 	   know for sure if we can take this lock or not. if we fail,