From 7c4bf742e82d812ecc5b0c3280db86d2689eb093 Mon Sep 17 00:00:00 2001 From: Debarshi Ray Date: Sun, 1 Mar 2015 13:28:21 +0100 Subject: [PATCH] eventcontroller, widget: Don't crash if destroyed before the other There are two scenarios. A widget sub-class owns a GtkEventController and passes itself to it, or a controller owned by something else is passed a widget. In the second case, if the widget is destroyed before the controller, we will have a crash when destructing the controller because we will be accessing invalid memory. Adding a weak reference on the widget addresses that problem. This leads to a crash in the first case. When the widget is getting destroyed, it will drop the reference to its own controller. The controller will skip touching the widget because the weak reference would have turned it to NULL. However, when the widget sub-class chains up to GtkWidget it will try to free all the controllers in its list. Unfortunately, all these controllers have already been destroyed. So we need to guard against this too. https://bugzilla.gnome.org/show_bug.cgi?id=745225 --- gtk/gtkeventcontroller.c | 1 + gtk/gtkwidget.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/gtk/gtkeventcontroller.c b/gtk/gtkeventcontroller.c index 4a77040bdd..c20c84e0d3 100644 --- a/gtk/gtkeventcontroller.c +++ b/gtk/gtkeventcontroller.c @@ -75,6 +75,7 @@ gtk_event_controller_set_property (GObject *object, { case PROP_WIDGET: priv->widget = g_value_get_object (value); + g_object_add_weak_pointer (G_OBJECT (priv->widget), (gpointer *) &priv->widget); break; case PROP_PROPAGATION_PHASE: gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (object), diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c index 11307c6032..7f132df0c0 100644 --- a/gtk/gtkwidget.c +++ b/gtk/gtkwidget.c @@ -17221,6 +17221,8 @@ _gtk_widget_add_controller (GtkWidget *widget, g_signal_connect (widget, "grab-notify", G_CALLBACK (event_controller_grab_notify), data); + g_object_add_weak_pointer (G_OBJECT (data->controller), (gpointer *) &data->controller); + if (GTK_IS_GESTURE (controller)) { data->sequence_state_changed_id = -- 2.30.2