[gnome-software] trivial: Fix a crash when installing local packages

[Richard Hughes <rhughes src gnome org>]

commit 7a40aa7f599e7bfc647313fe64e684d0d218309e
Author: Richard Hughes <richard hughsie com>
Date:   Wed Jan 29 11:04:11 2014 +0000

    trivial: Fix a crash when installing local packages

 src/gs-folders.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/gs-folders.c b/src/gs-folders.c
index e91328e..4aedf6f 100644
--- a/src/gs-folders.c
+++ b/src/gs-folders.c
@@ -491,6 +491,9 @@ gs_folders_get_app_folder (GsFolders *folders, const gchar *app, GPtrArray *cate
 {
        GsFolder *folder;
 
+       if (app == NULL)
+               return NULL;
+
        folder = get_app_folder (folders, app, categories);
 
        return folder ? folder->id : NULL;