GSList  const *items = selection->itemList();

int selObj = g_slist_length (const_cast<GSList*>(items)); 

the const_cast was required because:

guint       g_slist_length                  (GSList *list);

If I comment out the g_slist_length command, there is no runtime error. And Inkscape run's perfect. 
In this scenario, what can I do to get the length of the GSList ?

Arshdeep Singh
Third Year, Computer Engineering
Delhi Technological University
Ph: +91-9654115614
https://sites.google.com/site/adsingh1729/home