Made LB_GETCURSEL return focus_item if no item has been selected.

diff --git a/controls/listbox.c b/controls/listbox.c
index a298ff9..736922a 100644
--- a/controls/listbox.c
+++ b/controls/listbox.c
@@ -2229,6 +2229,9 @@
     case LB_GETCURSEL16:
     case LB_GETCURSEL:
         retvalue = descr->selected_item;
+        if (retvalue == -1) retvalue = descr->focus_item;
+        /* otherwise, if the user tries to move the selection with the    */
+        /* arrow keys, we will give the application something to choke on */
         goto END;
 
     case LB_GETTOPINDEX16: