--- a/src/fiber_thread.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/fiber_thread.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -32,7 +32,7 @@
 	{
 		this->m_sem = ThreadSemaphore::New();
 		/* Create a thread and start stFiberProc */
-		this->m_thread = ThreadObject::New(&stFiberProc, this);
+		this->m_thread = ThreadObject::New(&stFiberProc, this, NULL);
 	}
 
 	/**

--- a/src/genworld.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/genworld.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -288,7 +288,7 @@
 	SetupColorsAndInitialWindow();
 
 	if (_network_dedicated ||
-	    (_gw.thread = ThreadObject::New(&_GenerateWorld, NULL)) == NULL) {
+	    (_gw.thread = ThreadObject::New(&_GenerateWorld, NULL, &ThreadObject::TerminateCleanup)) == NULL) {
 		DEBUG(misc, 1, "Cannot create genworld thread, reverting to single-threaded mode");
 		_gw.threaded = false;
 		_GenerateWorld(NULL);

--- a/src/saveload.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/saveload.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -1695,7 +1695,7 @@
 
 			SaveFileStart();
 			if (_network_server ||
-						(_save_thread = ThreadObject::New(&SaveFileToDiskThread, NULL)) == NULL) {
+						(_save_thread = ThreadObject::New(&SaveFileToDiskThread, NULL, &ThreadObject::TerminateCleanup)) == NULL) {
 				if (!_network_server) DEBUG(sl, 1, "Cannot create savegame thread, reverting to single-threaded mode...");
 
 				SaveOrLoadResult result = SaveFileToDisk(false);

--- a/src/thread.h	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/thread.h	Sun Jun 08 12:06:27 2008 +0000
@@ -6,6 +6,7 @@
 #define THREAD_H
 
 typedef void (*OTTDThreadFunc)(void *);
+typedef void (*OTTDThreadTerminateFunc)(class ThreadObject *self);
 
 /**
  * A Thread Object which works on all our supported OSes.
@@ -56,9 +57,10 @@
 	 *  with optinal params.
 	 * @param proc The procedure to call inside the thread.
 	 * @param param The params to give with 'proc'.
+	 * @param terminate_func The function (or NULL) to call when the thread terminates.
 	 * @return True if the thread was started correctly.
 	 */
-	static ThreadObject *New(OTTDThreadFunc proc, void *param);
+	static ThreadObject *New(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func);
 
 	/**
 	 * Convert the current thread to a new ThreadObject.
@@ -71,6 +73,12 @@
 	 * @return The thread ID of the current active thread.
 	 */
 	static uint CurrentId();
+
+	/**
+	 * A OTTDThreadTerminateFunc, which cleans up the thread itself
+	 *  at termination of the thread (so it becomes self-managed).
+	 */
+	static void TerminateCleanup(ThreadObject *self) { delete self; }
 };
 
 /**

--- a/src/thread_morphos.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/thread_morphos.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -57,6 +57,7 @@
 class ThreadObject_MorphOS : public ThreadObject {
 private:
 	APTR m_thr;                  ///< System thread identifier.
+	OTTDThreadTerminateFunc m_terminate_func; ///< Function to call on thread termination.
 	struct MsgPort *m_replyport;
 	struct OTTDThreadStartupMessage m_msg;
 
@@ -64,7 +65,9 @@
 	/**
 	 * Create a sub process and start it, calling proc(param).
 	 */
-	ThreadObject_MorphOS(OTTDThreadFunc proc, void *param) : m_thr(0)
+	ThreadObject_MorphOS(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func) :
+		m_thr(0),
+		m_terminate_func(terminate_func)
 	{
 		struct Task *parent;
 
@@ -111,7 +114,9 @@
 	/**
 	 * Create a thread and attach current thread to it.
 	 */
-	ThreadObject_MorphOS() : m_thr(0)
+	ThreadObject_MorphOS() :
+		m_thr(0),
+		m_terminate_func(NULL)
 	{
 		m_thr = FindTask(NULL);
 	}
@@ -210,12 +215,14 @@
 
 		/*  Quit the child, exec.library will reply the startup msg internally. */
 		KPutStr("[Child] Done.\n");
+
+		if (this->terminate_func != NULL) this->terminate_func(this);
 	}
 };
 
-/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param)
+/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func)
 {
-	return new ThreadObject_MorphOS(proc, param);
+	return new ThreadObject_MorphOS(proc, param, terminate_func);
 }
 
 /* static */ ThreadObject *ThreadObject::AttachCurrent()

--- a/src/thread_none.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/thread_none.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -6,7 +6,7 @@
 #include "thread.h"
 #include "fiber.hpp"
 
-/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param)
+/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func)
 {
 	return NULL;
 }

--- a/src/thread_os2.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/thread_os2.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -59,7 +59,7 @@
 
 #endif
 
-/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param)
+/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func)
 {
 	return NULL;
 }

--- a/src/thread_pthread.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/thread_pthread.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -22,16 +22,18 @@
 	bool      m_attached;        ///< True if the ThreadObject was attached to an existing thread.
 	sem_t     m_sem_start;       ///< Here the new thread waits before it starts.
 	sem_t     m_sem_stop;        ///< Here the other thread can wait for this thread to end.
+	OTTDThreadTerminateFunc m_terminate_func; ///< Function to call on thread termination.
 
 public:
 	/**
 	 * Create a pthread and start it, calling proc(param).
 	 */
-	ThreadObject_pthread(OTTDThreadFunc proc, void *param) :
+	ThreadObject_pthread(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func) :
 		m_thr(0),
 		m_proc(proc),
 		m_param(param),
-		m_attached(false)
+		m_attached(false),
+		m_terminate_func(terminate_func)
 	{
 		sem_init(&m_sem_start, 0, 0);
 		sem_init(&m_sem_stop, 0, 0);
@@ -47,7 +49,8 @@
 		m_thr(0),
 		m_proc(NULL),
 		m_param(0),
-		m_attached(true)
+		m_attached(true),
+		m_terminate_func(NULL)
 	{
 		sem_init(&m_sem_start, 0, 0);
 		sem_init(&m_sem_stop, 0, 0);
@@ -102,8 +105,6 @@
 
 		pthread_join(m_thr, NULL);
 		m_thr = 0;
-
-		delete this;
 	}
 
 	/* virtual */ bool IsCurrent()
@@ -136,26 +137,22 @@
 		/* The new thread stops here so the calling thread can complete pthread_create() call */
 		sem_wait(&m_sem_start);
 
-		/* Did this thread die naturally/via exit, or did it join? */
-		bool exit = false;
-
 		/* Call the proc of the creator to continue this thread */
 		try {
 			m_proc(m_param);
 		} catch (...) {
-			exit = true;
 		}
 
 		/* Notify threads waiting for our completion */
 		sem_post(&m_sem_stop);
 
-		if (exit) delete this;
+		if (this->m_terminate_func != NULL) this->m_terminate_func(this);
 	}
 };
 
-/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param)
+/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func)
 {
-	return new ThreadObject_pthread(proc, param);
+	return new ThreadObject_pthread(proc, param, terminate_func);
 }
 
 /* static */ ThreadObject *ThreadObject::AttachCurrent()

--- a/src/thread_win32.cpp	Sun Jun 08 10:51:36 2008 +0000
+++ b/src/thread_win32.cpp	Sun Jun 08 12:06:27 2008 +0000
@@ -20,17 +20,19 @@
 	OTTDThreadFunc m_proc;
 	void     *m_param;
 	bool     m_attached;
+	OTTDThreadTerminateFunc m_terminate_func;
 
 public:
 	/**
 	 * Create a win32 thread and start it, calling proc(param).
 	 */
-	ThreadObject_Win32(OTTDThreadFunc proc, void *param) :
+	ThreadObject_Win32(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func) :
 		m_id_thr(0),
 		m_h_thr(NULL),
 		m_proc(proc),
 		m_param(param),
-		m_attached(false)
+		m_attached(false),
+		m_terminate_func(terminate_func)
 	{
 		m_h_thr = (HANDLE)_beginthreadex(NULL, 0, &stThreadProc, this, CREATE_SUSPENDED, &m_id_thr);
 		if (m_h_thr == NULL) return;
@@ -45,7 +47,8 @@
 		m_h_thr(NULL),
 		m_proc(NULL),
 		m_param(NULL),
-		m_attached(false)
+		m_attached(false),
+		m_terminate_func(NULL)
 	{
 		BOOL ret = DuplicateHandle(GetCurrentProcess(), GetCurrentThread(), GetCurrentProcess(), &m_h_thr, 0, FALSE, DUPLICATE_SAME_ACCESS);
 		if (!ret) return;
@@ -130,12 +133,14 @@
 			m_proc(m_param);
 		} catch (...) {
 		}
+
+		if (this->m_terminate_func != NULL) this->m_terminate_func(this);
 	}
 };
 
-/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param)
+/* static */ ThreadObject *ThreadObject::New(OTTDThreadFunc proc, void *param, OTTDThreadTerminateFunc terminate_func)
 {
-	return new ThreadObject_Win32(proc, param);
+	return new ThreadObject_Win32(proc, param, terminate_func);
 }
 
 /* static */ ThreadObject* ThreadObject::AttachCurrent()