[gnome-shell] [ShellAppSystem] Don't crash if the menu system is empty

[Colin Walters <walters src gnome org>]

commit 2ce746e7dd64fc36b0767bd0551d2a6b7349a669
Author: Colin Walters <walters verbum org>
Date:   Thu May 20 17:06:30 2010 -0400

    [ShellAppSystem] Don't crash if the menu system is empty
    
    This is a bit pathological, but if your menu tree is empty, we
    shouldn't crash.

 src/shell-app-system.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/src/shell-app-system.c b/src/shell-app-system.c
index ad8cef4..faa960e 100644
--- a/src/shell-app-system.c
+++ b/src/shell-app-system.c
@@ -309,9 +309,15 @@ reread_entries (ShellAppSystem     *self,
   g_slist_free (*cache);
   *cache = NULL;
 
-  *cache = gather_entries_recurse (self, *cache, unique, trunk);
-
-  gmenu_tree_item_unref (trunk);
+  if (!trunk)
+    {
+      *cache = NULL;
+    }
+  else
+    {
+      *cache = gather_entries_recurse (self, *cache, unique, trunk);
+      gmenu_tree_item_unref (trunk);
+    }
 }
 
 static void