From b37787a4140d2b993e35ae1d0b019d0af04c2fd1 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 7 Oct 2017 19:14:18 -0400
Subject: [PATCH] Ensures lifetime-linked track flushing without relying on
 virtual calls within a destructor.

---
 Storage/Disk/Disk.hpp  | 4 +---
 Storage/Disk/Drive.cpp | 5 +++++
 Storage/Disk/Drive.hpp | 1 +
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/Storage/Disk/Disk.hpp b/Storage/Disk/Disk.hpp
index 95e5bc4a9..c929bff3a 100644
--- a/Storage/Disk/Disk.hpp
+++ b/Storage/Disk/Disk.hpp
@@ -23,9 +23,7 @@ namespace Disk {
 
 class Disk {
 	public:
-		virtual ~Disk() {
-			flush_tracks();
-		}
+		virtual ~Disk() {}
 
 		/*!
 			@returns the number of discrete positions that this disk uses to model its complete surface area.
diff --git a/Storage/Disk/Drive.cpp b/Storage/Disk/Drive.cpp
index 14866185f..e94df592a 100644
--- a/Storage/Disk/Drive.cpp
+++ b/Storage/Disk/Drive.cpp
@@ -21,7 +21,12 @@ Drive::Drive(unsigned int input_clock_rate, int revolutions_per_minute, int numb
 	available_heads_(number_of_heads) {
 }
 
+Drive::~Drive() {
+	if(disk_) disk_->flush_tracks();
+}
+
 void Drive::set_disk(const std::shared_ptr<Disk> &disk) {
+	if(disk_) disk_->flush_tracks();
 	disk_ = disk;
 	has_disk_ = !!disk_;
 
diff --git a/Storage/Disk/Drive.hpp b/Storage/Disk/Drive.hpp
index 266ad7d54..7f321068c 100644
--- a/Storage/Disk/Drive.hpp
+++ b/Storage/Disk/Drive.hpp
@@ -24,6 +24,7 @@ namespace Disk {
 class Drive: public Sleeper, public TimedEventLoop {
 	public:
 		Drive(unsigned int input_clock_rate, int revolutions_per_minute, int number_of_heads);
+		~Drive();
 
 		/*!
 			Replaces whatever is in the drive with @c disk.