[evince] shell: Disconnect signal handler to prevent invalid read

[Germán Poo-Caamaño <gpoo src gnome org>]

commit c56e68964fe97dc187f28bd66ba925a3e3b412d8
Author: Marek Kasik <mkasik redhat com>
Date:   Thu Apr 28 17:00:22 2022 +0200

    shell: Disconnect signal handler to prevent invalid read
    
    Disconnect handler of "finished" signal of EvJobAnnots in EvSidebarAnnotations'
    dispose method.
    This prevents the callback to access the EvSidebarAnnotations object after
    it has been disposed if the job takes a long time.
    
    Fixes #1784

 shell/ev-sidebar-annotations.c | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/shell/ev-sidebar-annotations.c b/shell/ev-sidebar-annotations.c
index bc43dc2cd..21595e49e 100644
--- a/shell/ev-sidebar-annotations.c
+++ b/shell/ev-sidebar-annotations.c
@@ -70,6 +70,8 @@ static gboolean ev_sidebar_annotations_popup_menu_show (EvSidebarAnnotations *si
                                                        const GdkRectangle   *rect,
                                                        EvMapping            *annot_mapping,
                                                        const GdkEvent       *event);
+static void job_finished_callback (EvJobAnnots          *job,
+                                  EvSidebarAnnotations *sidebar_annots);
 static guint signals[N_SIGNALS];
 
 G_DEFINE_TYPE_EXTENDED (EvSidebarAnnotations,
@@ -88,6 +90,13 @@ ev_sidebar_annotations_dispose (GObject *object)
        EvSidebarAnnotations *sidebar_annots = EV_SIDEBAR_ANNOTATIONS (object);
        EvSidebarAnnotationsPrivate *priv = sidebar_annots->priv;
 
+       if (priv->job != NULL) {
+               g_signal_handlers_disconnect_by_func (priv->job,
+                                                     job_finished_callback,
+                                                     sidebar_annots);
+               g_clear_object (&priv->job);
+       }
+
        if (priv->document) {
                g_object_unref (priv->document);
                priv->document = NULL;