[glib] Fix default setting generation in g_desktop_app_info_set_as_last_used

[Josselin Mouette <jmouette src gnome org>]

commit a13f5ca4da05c3a7edaed9a70c508f63772897cb
Author: Josselin Mouette <joss debian org>
Date:   Sat Sep 10 08:26:12 2011 +0200

    Fix default setting generation in g_desktop_app_info_set_as_last_used
    
     * Do not ignore the system default
     * Do not exclude the last used being set from the default list
    
    This fixes the default applications dialog in control-center.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=658188

 gio/gdesktopappinfo.c |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)
---
diff --git a/gio/gdesktopappinfo.c b/gio/gdesktopappinfo.c
index 2df933f..d4a5615 100644
--- a/gio/gdesktopappinfo.c
+++ b/gio/gdesktopappinfo.c
@@ -1688,18 +1688,29 @@ update_mimeapps_list (const char  *desktop_id,
            */
           if (!explicit_default)
             {
-              system_list = get_all_desktop_entries_for_mime_type (content_type, (const char **) list, FALSE, NULL);
+              char *user_default;
+              /* The system default can be in the list, don't exclude it */
+              system_list = get_all_desktop_entries_for_mime_type (content_type, NULL, FALSE, &user_default);
 
-              if (system_list != NULL)
+              string = NULL;
+              if (user_default != NULL)
+                {
+                  /* There is an existing default set in a lower priority defaults file, re-use it */
+                  string = user_default;
+                }
+              else if (system_list != NULL)
                 {
                   string = system_list->data;
-
+                }
+              if (string)
+                {
                   g_key_file_set_string (key_file,
                                          DEFAULT_APPLICATIONS_GROUP,
                                          content_types[k],
                                          string);
                 }
 
+              g_free (user_default);
               g_list_free_full (system_list, g_free);
             }
         }