[gtksourceview] hoverassistant: dont toggle visibility after disposal

[Christian Hergert <chergert src gnome org>]

commit fc72fa35ccfacbc7b2ab22103e4e90f05e777a41
Author: Christian Hergert <chergert redhat com>
Date:   Wed Aug 31 12:37:37 2022 -0700

    hoverassistant: dont toggle visibility after disposal
    
    Avoid a race condition if we are force disposed while the action is
    processed. Doesn't happen in practice, but I'd prefer to be explicit here.

 gtksourceview/gtksourcehoverassistant.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/gtksourceview/gtksourcehoverassistant.c b/gtksourceview/gtksourcehoverassistant.c
index 7de6cb81..1abe01bc 100644
--- a/gtksourceview/gtksourcehoverassistant.c
+++ b/gtksourceview/gtksourcehoverassistant.c
@@ -52,6 +52,8 @@ struct _GtkSourceHoverAssistant
        gulong root_leave_handler;
 
        GSource *dismiss_source;
+
+       guint disposed : 1;
 };
 
 G_DEFINE_TYPE (GtkSourceHoverAssistant, gtk_source_hover_assistant, GTK_SOURCE_TYPE_ASSISTANT)
@@ -289,6 +291,8 @@ gtk_source_hover_assistant_dispose (GObject *object)
 {
        GtkSourceHoverAssistant *self = (GtkSourceHoverAssistant *)object;
 
+       self->disposed = TRUE;
+
        self->display = NULL;
 
        g_clear_pointer (&self->dismiss_source, g_source_destroy);
@@ -360,8 +364,11 @@ gtk_source_hover_assistant_populate_cb (GObject      *object,
 
        if (_gtk_source_hover_context_populate_finish (context, result, &error))
        {
-               gtk_widget_set_visible (GTK_WIDGET (self),
-                                       !_gtk_source_hover_display_is_empty (self->display));
+               if (!self->disposed)
+               {
+                       gtk_widget_set_visible (GTK_WIDGET (self),
+                                               !_gtk_source_hover_display_is_empty (self->display));
+               }
        }
 
        g_clear_object (&self);