[gnome-packagekit] Fix a segfault when there is a distribution upgrade available

[Richard Hughes <rhughes src gnome org>]

commit a547582193fcee431786a73c3967411b98fd9bde
Author: Richard Hughes <richard hughsie com>
Date:   Fri Oct 5 22:38:35 2012 +0100

    Fix a segfault when there is a distribution upgrade available
    
    Resolves: https://bugzilla.gnome.org/show_bug.cgi?id=685579

 src/gpk-update-viewer.c |   18 ++++++++++--------
 1 files changed, 10 insertions(+), 8 deletions(-)
---
diff --git a/src/gpk-update-viewer.c b/src/gpk-update-viewer.c
index 04ba4ee..142bf5b 100644
--- a/src/gpk-update-viewer.c
+++ b/src/gpk-update-viewer.c
@@ -1459,14 +1459,16 @@ gpk_update_viewer_reconsider_info (void)
 	gtk_button_set_label (GTK_BUTTON (widget), title);
 
 	/* no updates */
-	len = update_array->len;
-	if (len == 0) {
-		gpk_update_viewer_modal_error_with_timeout (
-				/* TRANSLATORS: title: nothing to do */
-				_("All software is up to date"),
-				/* TRANSLATORS: tell the user the problem */
-				_("There are no software updates available for your computer at this time."));
-		goto out;
+	if (update_array != NULL) {
+		len = update_array->len;
+		if (len == 0) {
+			gpk_update_viewer_modal_error_with_timeout (
+					/* TRANSLATORS: title: nothing to do */
+					_("All software is up to date"),
+					/* TRANSLATORS: tell the user the problem */
+					_("There are no software updates available for your computer at this time."));
+			goto out;
+		}
 	}
 
 	/* use correct status pane */