From 9ad273d83454851d5ab112905db721d50554dcb6 Mon Sep 17 00:00:00 2001
From: Matthias Koefferlein <matthias@klayout.de>
Date: Mon, 20 Apr 2026 22:19:56 +0200
Subject: [PATCH] Fixing a segfault on 'xkill' - solution was to register an
 exit handler that cleanly shuts down

---
 src/lay/lay/layApplication.cc         | 10 ++++++++++
 src/lay/lay/layApplication.h          | 10 +++++++++-
 src/lay/lay/layMainWindow.cc          |  1 -
 src/lay/lay/layMainWindow.h           |  1 -
 src/laybasic/laybasic/layDispatcher.h |  3 ++-
 5 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/src/lay/lay/layApplication.cc b/src/lay/lay/layApplication.cc
index 63b6450cf..259a272b0 100644
--- a/src/lay/lay/layApplication.cc
+++ b/src/lay/lay/layApplication.cc
@@ -1658,6 +1658,12 @@ GuiApplication::event (QEvent *event)
   return QApplication::event(event);
 }
 
+static void atexit_handler ()
+{
+  if (lay::ApplicationBase::instance ()) {
+    lay::ApplicationBase::instance ()->shutdown ();
+  }
+}
 
 int
 GuiApplication::exec ()
@@ -1693,6 +1699,10 @@ GuiApplication::exec ()
 
   }
 
+  //  register an exit handler to shutdown cleanly in case of an explicit exit
+  //  inside the code
+  ::atexit (&atexit_handler);
+
   return QApplication::exec ();
 }
 
diff --git a/src/lay/lay/layApplication.h b/src/lay/lay/layApplication.h
index e268df204..2a1322dfe 100644
--- a/src/lay/lay/layApplication.h
+++ b/src/lay/lay/layApplication.h
@@ -105,6 +105,15 @@ public:
    */
   void exit (int result);
 
+  /**
+   *  @brief Shut down the application
+   *
+   *  Calling this function will close the main window and
+   *  prepare for exit. Unlike "exit", it dows not actually exit
+   *  the process.
+   */
+  virtual void shutdown ();
+
   /**
    *  @brief Return the program's version
    */
@@ -330,7 +339,6 @@ public:
 
 protected:
   virtual void setup () = 0;
-  virtual void shutdown ();
   virtual void prepare_recording (const std::string &gtf_record, bool gtf_record_incremental);
   virtual void start_recording ();
   virtual lay::Dispatcher *dispatcher () const = 0;
diff --git a/src/lay/lay/layMainWindow.cc b/src/lay/lay/layMainWindow.cc
index 13c76abcf..f63026e95 100644
--- a/src/lay/lay/layMainWindow.cc
+++ b/src/lay/lay/layMainWindow.cc
@@ -165,7 +165,6 @@ show_dock_widget (QDockWidget *dock_widget, bool visible)
 
 MainWindow::MainWindow (QApplication *app, const char *name, bool undo_enabled)
     : QMainWindow (0),
-      tl::Object (),
       lay::DispatcherDelegate (),
       m_dispatcher (this),
       m_text_progress (this, 10 /*verbosity threshold*/),
diff --git a/src/lay/lay/layMainWindow.h b/src/lay/lay/layMainWindow.h
index e1fc24972..a22ac7bc9 100644
--- a/src/lay/lay/layMainWindow.h
+++ b/src/lay/lay/layMainWindow.h
@@ -94,7 +94,6 @@ class ProgressWidget;
  */
 class LAY_PUBLIC MainWindow
   : public QMainWindow,
-    public tl::Object,
     public gsi::ObjectBase,
     public lay::DispatcherDelegate
 {
diff --git a/src/laybasic/laybasic/layDispatcher.h b/src/laybasic/laybasic/layDispatcher.h
index f42b60585..df26686d8 100644
--- a/src/laybasic/laybasic/layDispatcher.h
+++ b/src/laybasic/laybasic/layDispatcher.h
@@ -49,6 +49,7 @@ class ConfigureAction;
  *  @brief A delegate by which the dispatcher can submit notification events
  */
 class LAYBASIC_PUBLIC DispatcherDelegate
+  : public tl::Object
 {
 public:
   /**
@@ -271,7 +272,7 @@ private:
 #if defined(HAVE_QT)
   QWidget *mp_menu_parent_widget;
 #endif
-  DispatcherDelegate *mp_delegate;
+  tl::weak_ptr<DispatcherDelegate> mp_delegate;
 };
 
 }