fixed: make sure we validate CAddonMgr::GetDefaults return value

git-svn-id: https://xbmc.svn.sourceforge.net/svnroot/xbmc/trunk@28613 568bbfeb-2a22-0410-94d2-cc84cf5bfa90

Author: elupus

xbmc/GUIDialogContentSettings.cpp

@@ -250,8 +250,7 @@ void CGUIDialogContentSettings::FillContentTypes(const CONTENT_TYPE &content)
 
   AddonPtr addon;
   CStdString defaultID;
-  CAddonMgr::Get()->GetDefault(ADDON_SCRAPER, addon, content);
-  if (addon)
+  if (CAddonMgr::Get()->GetDefault(ADDON_SCRAPER, addon, content))
     defaultID = addon->ID();
 
   for (IVECADDONS it = addons.begin(); it != addons.end(); it++)

xbmc/GUIWindowVisualisation.cpp

@@ -176,7 +176,9 @@ bool CGUIWindowVisualisation::OnMessage(CGUIMessage& message)
       }
 
       AddonPtr viz;
-      CAddonMgr::Get()->GetDefault(ADDON_VIZ, viz);
+      if (!CAddonMgr::Get()->GetDefault(ADDON_VIZ, viz))
+        return false;
+
       m_addon = boost::dynamic_pointer_cast<CVisualisation>(viz);
       if (!m_addon)
         return false;