From 4db32dd1342ba8a3461652c8964f1e356c133696 Mon Sep 17 00:00:00 2001
From: Don Gagne <DonLakeFlyer@users.noreply.github.com>
Date: Sun, 18 Oct 2020 11:12:23 -0700
Subject: [PATCH] Prevent stale readBytes signalling to call into deleted
 objects (#9116)

---
 src/comm/BluetoothLink.cc | 2 ++
 src/comm/SerialLink.cc    | 2 ++
 src/comm/TCPLink.cc       | 2 ++
 src/comm/UDPLink.cc       | 2 ++
 4 files changed, 8 insertions(+)

diff --git a/src/comm/BluetoothLink.cc b/src/comm/BluetoothLink.cc
index 0babaeeb9..ede027ed6 100644
--- a/src/comm/BluetoothLink.cc
+++ b/src/comm/BluetoothLink.cc
@@ -86,6 +86,8 @@ void BluetoothLink::disconnect(void)
     }
 #endif
     if(_targetSocket) {
+        // This prevents stale signals from calling the link after it has been deleted
+        QObject::connect(_targetSocket, &QBluetoothSocket::readyRead, this, &BluetoothLink::readBytes);
         _targetSocket->deleteLater();
         _targetSocket = nullptr;
         emit disconnected();
diff --git a/src/comm/SerialLink.cc b/src/comm/SerialLink.cc
index 4216a67c4..3ed29fd9f 100644
--- a/src/comm/SerialLink.cc
+++ b/src/comm/SerialLink.cc
@@ -79,6 +79,8 @@ void SerialLink::_writeBytes(const QByteArray data)
 void SerialLink::disconnect(void)
 {
     if (_port) {
+        // This prevents stale signals from calling the link after it has been deleted
+        QObject::disconnect(_port, &QIODevice::readyRead, this, &SerialLink::_readBytes);
         _port->close();
         _port->deleteLater();
         _port = nullptr;
diff --git a/src/comm/TCPLink.cc b/src/comm/TCPLink.cc
index 5e4cc3658..12cd5c049 100644
--- a/src/comm/TCPLink.cc
+++ b/src/comm/TCPLink.cc
@@ -106,6 +106,8 @@ void TCPLink::disconnect(void)
     quit();
     wait();
     if (_socket) {
+        // This prevents stale signal from calling the link after it has been deleted
+        QObject::connect(_socket, &QTcpSocket::readyRead, this, &TCPLink::readBytes);
         _socketIsConnected = false;
         _socket->disconnectFromHost(); // Disconnect tcp
         _socket->waitForDisconnected();        
diff --git a/src/comm/UDPLink.cc b/src/comm/UDPLink.cc
index cb16f61bd..4c14e916e 100644
--- a/src/comm/UDPLink.cc
+++ b/src/comm/UDPLink.cc
@@ -222,6 +222,8 @@ void UDPLink::disconnect(void)
     quit();
     wait();
     if (_socket) {
+        // This prevents stale signal from calling the link after it has been deleted
+        QObject::disconnect(_socket, &QUdpSocket::readyRead, this, &UDPLink::readBytes);
         // Make sure delete happen on correct thread
         _socket->deleteLater();
         _socket = nullptr;
-- 
2.22.0