[gnome-panel] status-notifier: avoid a possible crash in register_host_cb

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 5f16dadc9ed1bdc313fa6847e23dc1bbe3e999e6
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Fri Dec 29 01:27:46 2017 +0200

    status-notifier: avoid a possible crash in register_host_cb
    
    sn_watcher_v0_gen_dup_registered_items() can return NULL if
    property is not set.

 modules/status-notifier/sn-host-v0.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/modules/status-notifier/sn-host-v0.c b/modules/status-notifier/sn-host-v0.c
index 1693e56..6c2d2fa 100644
--- a/modules/status-notifier/sn-host-v0.c
+++ b/modules/status-notifier/sn-host-v0.c
@@ -204,6 +204,8 @@ register_host_cb (GObject      *source_object,
                     G_CALLBACK (item_unregistered_cb), v0);
 
   items = sn_watcher_v0_gen_dup_registered_items (v0->watcher);
+  if (items == NULL)
+    return;
 
   for (i = 0; items[i] != NULL; i++)
     add_registered_item (v0, items[i]);