[gnome-software] GsShell: Improve back stack

[Matthias Clasen <matthiasc src gnome org>]

commit 17b093637b94662fefafde5f560c694d7068e836
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Aug 31 19:20:46 2013 -0400

    GsShell: Improve back stack
    
    Future-proof this a bit, by also supporting going back
    to an app page - this may be used in the future when we
    get 'related' links on the app details page.

 src/gs-shell.c |   18 ++++++++++++++++--
 1 files changed, 16 insertions(+), 2 deletions(-)
---
diff --git a/src/gs-shell.c b/src/gs-shell.c
index 6547f77..12cebc1 100644
--- a/src/gs-shell.c
+++ b/src/gs-shell.c
@@ -166,12 +166,26 @@ save_back_entry (GsShell *shell)
         entry = g_new0 (BackEntry, 1);
         entry->mode = priv->mode;
 
-        if (priv->mode == GS_SHELL_MODE_CATEGORY)
+        if (priv->mode == GS_SHELL_MODE_CATEGORY) {
                 entry->category = gs_shell_category_get_category (priv->shell_category);
+                g_object_ref (entry->category);
+        }
+        else if (priv->mode == GS_SHELL_MODE_DETAILS) {
+                entry->app = gs_shell_details_get_app (priv->shell_details);
+                g_object_ref (entry->app);
+        }
 
         priv->back_entry_stack = g_slist_prepend (priv->back_entry_stack, entry);
 }
 
+static void
+free_back_entry (BackEntry *entry)
+{
+        g_clear_object (&entry->category);
+        g_clear_object (&entry->app);
+        g_free (entry);
+}
+
 /**
  * gs_shell_back_button_cb:
  **/
@@ -187,7 +201,7 @@ gs_shell_back_button_cb (GtkWidget *widget, GsShell *shell)
 
        gs_shell_change_mode (shell, entry->mode, entry->app, entry->category);
 
-        g_free (entry);
+        free_back_entry (entry);
 }
 
 static void