GTK+ selects the first item initially

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@48797 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/choice.cpp

@@ -118,8 +118,8 @@ bool wxChoice::Create( wxWindow *parent, wxWindowID id,
         m_strings = new wxSortedArrayString;
     }
 
-    // begin with no selection
-    m_selection_hack = wxNOT_FOUND;
+    // If we have items, GTK will choose the first item by default
+    m_selection_hack = n > 0 ? 0 : wxNOT_FOUND;
 
     GtkWidget *menu = gtk_menu_new();