[evolution] Bug 770496 - Accessing NULL GDBusProxy on shutdown

[Milan Crha <mcrha src gnome org>]

commit 2d4605d74b3dcf95342297f9c9587b7262de8a37
Author: Hans Petter Jansson <hpj cl no>
Date:   Wed Aug 31 10:55:40 2016 +0200

    Bug 770496 - Accessing NULL GDBusProxy on shutdown

 mail/e-mail-display.c |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)
---
diff --git a/mail/e-mail-display.c b/mail/e-mail-display.c
index 5fee3b8..5fc90f7 100644
--- a/mail/e-mail-display.c
+++ b/mail/e-mail-display.c
@@ -1330,16 +1330,20 @@ mail_display_dispose (GObject *object)
                priv->scheduled_reload = 0;
        }
 
-       if (priv->settings != NULL)
+       if (priv->settings != NULL) {
                g_signal_handlers_disconnect_matched (
                        priv->settings, G_SIGNAL_MATCH_DATA,
                        0, 0, NULL, NULL, object);
+       }
 
        if (priv->web_extension_headers_collapsed_signal_id > 0) {
-               g_dbus_connection_signal_unsubscribe (
-                       g_dbus_proxy_get_connection (
-                               e_web_view_get_web_extension_proxy (E_WEB_VIEW (object))),
-                       priv->web_extension_headers_collapsed_signal_id);
+               GDBusProxy *web_extension = e_web_view_get_web_extension_proxy (E_WEB_VIEW (object));
+
+               if (web_extension != NULL) {
+                       g_dbus_connection_signal_unsubscribe (
+                               g_dbus_proxy_get_connection (web_extension),
+                               priv->web_extension_headers_collapsed_signal_id);
+               }
                priv->web_extension_headers_collapsed_signal_id = 0;
        }