From 9ccc56e162554c292b25408246e3680b8f14eea7 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sat, 8 Dec 2018 21:18:54 +0100
Subject: [PATCH] Fix CheckOption crash on session-reload

The ToggleAction has a lifetime of the UI, independent of the
CheckOption widget. The CheckOption needs to unsubscribe from the
signal_toggled() signal when it is deleted.

Also a CheckOption without a Action makes no sense. require _action
to be give at instantiation time.
---
 gtk2_ardour/option_editor.cc | 22 +++++++++++++---------
 gtk2_ardour/option_editor.h  |  8 +++++---
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/gtk2_ardour/option_editor.cc b/gtk2_ardour/option_editor.cc
index 875e611452..3482f66980 100644
--- a/gtk2_ardour/option_editor.cc
+++ b/gtk2_ardour/option_editor.cc
@@ -213,18 +213,22 @@ CheckOption::CheckOption (string const & i, string const & n, Glib::RefPtr<Gtk::
 	_button->signal_toggled().connect (sigc::mem_fun (*this, &CheckOption::toggled));
 
 	Gtkmm2ext::Activatable::set_related_action (act);
-	if (_action) {
+	assert (_action);
 
-		action_sensitivity_changed ();
+	action_sensitivity_changed ();
 
-		Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);
-		if (tact) {
-			action_toggled ();
-			tact->signal_toggled().connect (sigc::mem_fun (*this, &CheckOption::action_toggled));
-		}
-
-		_action->connect_property_changed ("sensitive", sigc::mem_fun (*this, &CheckOption::action_sensitivity_changed));
+	Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);
+	if (tact) {
+		action_toggled ();
+		_callback_connection = tact->signal_toggled().connect (sigc::mem_fun (*this, &CheckOption::action_toggled));
 	}
+
+	_action->connect_property_changed ("sensitive", sigc::mem_fun (*this, &CheckOption::action_sensitivity_changed));
+}
+
+CheckOption::~CheckOption ()
+{
+	_callback_connection.disconnect ();
 }
 
 void
diff --git a/gtk2_ardour/option_editor.h b/gtk2_ardour/option_editor.h
index d6738889f3..749df8f90c 100644
--- a/gtk2_ardour/option_editor.h
+++ b/gtk2_ardour/option_editor.h
@@ -193,6 +193,7 @@ class CheckOption : public OptionEditorComponent , public Gtkmm2ext::Activatable
 {
 public:
 	CheckOption (std::string const &, std::string const &, Glib::RefPtr<Gtk::Action> act );
+	virtual ~CheckOption ();
 	void set_state_from_config () {}
 	void parameter_changed (std::string const &) {}
 	void add_to_page (OptionEditorPage*);
@@ -203,17 +204,18 @@ public:
 
 	Gtk::Widget& tip_widget() { return *_button; }
 
+protected:
 	void action_toggled ();
 	void action_sensitivity_changed () {}
 	void action_visibility_changed () {}
 
-protected:
 	virtual void toggled ();
 
-	sigc::slot<bool>       _get; ///< slot to get the configuration variable's value
-	sigc::slot<bool, bool> _set;  ///< slot to set the configuration variable's value
 	Gtk::CheckButton*      _button; ///< UI button
 	Gtk::Label*            _label; ///< label for button, so we can use markup
+
+private:
+	sigc::connection       _callback_connection;
 };
 
 /** Component which provides the UI to handle a boolean option using a GTK CheckButton */
-- 
2.30.2