From eb6755e1ca400249d54582a7a763b3114e143e23 Mon Sep 17 00:00:00 2001
From: "Eduardo Lima (Etrunko)" <etrunko@redhat.com>
Date: Wed, 25 Jan 2017 17:41:20 -0200
Subject: [PATCH 16/26] iso-dialog: Avoid crash when closing dialog early

We must take into account that users can close the dialog at anytime,
even during an operation of fetch or set ISO has not been finished. This
will cause the callbacks for those operations to be invoked with an
invalid object, crashing the application.

To fix this issue we need to pass a GCancellable to the asynchronous
operations, so they can be cancelled if the dialog happens to get closed
before they complete.

NOTE: This patch triggers a deadlock in libgovirt when the dialog is
closed before the operation completes. Bug reported in
https://bugzilla.gnome.org/show_bug.cgi?id=777808. We will need to bump
libgovirt dependency whenever it has a new release.

Signed-off-by: Eduardo Lima (Etrunko) <etrunko@redhat.com>
---
 src/remote-viewer-iso-list-dialog.c | 42 ++++++++++++++++++++++++++++++-------
 1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/src/remote-viewer-iso-list-dialog.c b/src/remote-viewer-iso-list-dialog.c
index 2ab5435..745768a 100644
--- a/src/remote-viewer-iso-list-dialog.c
+++ b/src/remote-viewer-iso-list-dialog.c
@@ -42,6 +42,7 @@ struct _RemoteViewerISOListDialogPrivate
     GtkWidget *stack;
     GtkWidget *tree_view;
     OvirtForeignMenu *foreign_menu;
+    GCancellable *cancellable;
 };
 
 enum RemoteViewerISOListDialogModel
@@ -66,6 +67,8 @@ remote_viewer_iso_list_dialog_dispose(GObject *object)
     RemoteViewerISOListDialog *self = REMOTE_VIEWER_ISO_LIST_DIALOG(object);
     RemoteViewerISOListDialogPrivate *priv = self->priv;
 
+    g_clear_object(&priv->cancellable);
+
     if (priv->foreign_menu) {
         g_signal_handlers_disconnect_by_data(priv->foreign_menu, object);
         g_clear_object(&priv->foreign_menu);
@@ -157,17 +160,24 @@ fetch_iso_names_cb(OvirtForeignMenu *foreign_menu,
         const gchar *msg = error ? error->message : _("Failed to fetch CD names");
         gchar *markup = g_strdup_printf("<b>%s</b>", msg);
 
+        g_debug("Error fetching ISO names: %s", msg);
+        if (g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+            goto end;
+
         gtk_label_set_markup(GTK_LABEL(priv->status), markup);
         gtk_spinner_stop(GTK_SPINNER(priv->spinner));
         remote_viewer_iso_list_dialog_show_error(self, msg);
         gtk_dialog_set_response_sensitive(GTK_DIALOG(self), GTK_RESPONSE_NONE, TRUE);
         g_free(markup);
-        g_clear_error(&error);
-        return;
+        goto end;
     }
 
+    g_clear_object(&priv->cancellable);
     g_list_foreach(iso_list, (GFunc) remote_viewer_iso_list_dialog_foreach, self);
     remote_viewer_iso_list_dialog_show_files(self);
+
+end:
+    g_clear_error(&error);
 }
 
 
@@ -177,7 +187,10 @@ remote_viewer_iso_list_dialog_refresh_iso_list(RemoteViewerISOListDialog *self)
     RemoteViewerISOListDialogPrivate *priv = self->priv;
 
     gtk_list_store_clear(priv->list_store);
-    ovirt_foreign_menu_fetch_iso_names_async(priv->foreign_menu, NULL,
+
+    priv->cancellable = g_cancellable_new();
+    ovirt_foreign_menu_fetch_iso_names_async(priv->foreign_menu,
+                                             priv->cancellable,
                                              (GAsyncReadyCallback) fetch_iso_names_cb,
                                              self);
 }
@@ -190,8 +203,10 @@ remote_viewer_iso_list_dialog_response(GtkDialog *dialog,
     RemoteViewerISOListDialog *self = REMOTE_VIEWER_ISO_LIST_DIALOG(dialog);
     RemoteViewerISOListDialogPrivate *priv = self->priv;
 
-    if (response_id != GTK_RESPONSE_NONE)
+    if (response_id != GTK_RESPONSE_NONE) {
+        g_cancellable_cancel(priv->cancellable);
         return;
+    }
 
     gtk_spinner_start(GTK_SPINNER(priv->spinner));
     gtk_label_set_markup(GTK_LABEL(priv->status), _("<b>Loading...</b>"));
@@ -223,7 +238,9 @@ remote_viewer_iso_list_dialog_toggled(GtkCellRendererToggle *cell_renderer G_GNU
     gtk_dialog_set_response_sensitive(GTK_DIALOG(self), GTK_RESPONSE_NONE, FALSE);
     gtk_widget_set_sensitive(priv->tree_view, FALSE);
 
-    ovirt_foreign_menu_set_current_iso_name_async(priv->foreign_menu, active ? NULL : name, NULL,
+    priv->cancellable = g_cancellable_new();
+    ovirt_foreign_menu_set_current_iso_name_async(priv->foreign_menu, active ? NULL : name,
+                                                  priv->cancellable,
                                                   (GAsyncReadyCallback)ovirt_foreign_menu_iso_name_changed,
                                                   self);
     gtk_tree_path_free(tree_path);
@@ -308,12 +325,18 @@ ovirt_foreign_menu_iso_name_changed(OvirtForeignMenu *foreign_menu,
      * change the ISO back to the original, avoiding a possible inconsistency.
      */
     if (!ovirt_foreign_menu_set_current_iso_name_finish(foreign_menu, result, &error)) {
-        remote_viewer_iso_list_dialog_show_error(self, error ? error->message : _("Failed to change CD"));
-        g_clear_error(&error);
+        const gchar *msg = error ? error->message : _("Failed to change CD");
+        g_debug("Error changing ISO: %s", msg);
+
+        if (g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+            goto end;
+
+        remote_viewer_iso_list_dialog_show_error(self, msg);
     }
 
+    g_clear_object(&priv->cancellable);
     if (!gtk_tree_model_get_iter_first(model, &iter))
-        return;
+        goto end;
 
     current_iso = ovirt_foreign_menu_get_current_iso_name(foreign_menu);
 
@@ -340,6 +363,9 @@ ovirt_foreign_menu_iso_name_changed(OvirtForeignMenu *foreign_menu,
     gtk_dialog_set_response_sensitive(GTK_DIALOG(self), GTK_RESPONSE_NONE, TRUE);
     gtk_widget_set_sensitive(priv->tree_view, TRUE);
     g_free(current_iso);
+
+end:
+    g_clear_error(&error);
 }
 
 GtkWidget *
-- 
2.12.0