[gparted] Remove shadow border from partition information scrollable region (#690542)

[Mike Fleetwood <mfleetwo src gnome org>]

commit 960bb2c6cdfe70af11d49a47bc12237c7fcd70f6
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Tue Apr 22 11:40:34 2014 -0600

    Remove shadow border from partition information scrollable region (#690542)
    
    Bug 690542 - Partition Information Dialog Warning not readable

 src/Dialog_Partition_Info.cc |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
---
diff --git a/src/Dialog_Partition_Info.cc b/src/Dialog_Partition_Info.cc
index 4ab27f8..d9edc3b 100644
--- a/src/Dialog_Partition_Info.cc
+++ b/src/Dialog_Partition_Info.cc
@@ -18,6 +18,8 @@
 #include "../include/Dialog_Partition_Info.h"
 #include "../include/LVM2_PV_Info.h"
 
+#include <gtk/gtk.h>
+
 namespace GParted
 {
 
@@ -45,6 +47,14 @@ Dialog_Partition_Info::Dialog_Partition_Info( const Partition & partition )
        info_msg_vbox .set_border_width( 6 ) ;
        info_scrolled .set_policy( Gtk::POLICY_NEVER, Gtk::POLICY_AUTOMATIC ) ;
        info_scrolled .add( info_msg_vbox ) ;
+       //As Gtk::VBox widget info_msg_vbox doesn't have a native scrolling capability a
+       //  Gtk::Viewport is automatically created to contain it when it is added to the
+       //  Gtk::ScrolledWindow widget info_scrolled.  The Viewport widget is created with
+       //  shadow type GTK_SHADOW_IN by default.  Change to GTK_SHADOW_NONE.  Have to use
+       //  GTK+ C API as the Viewport widget isn't exposed via gtkmm C++ API.
+       //  
https://developer.gnome.org/gtkmm/2.24/classGtk_1_1ScrolledWindow.html#a17c588d56d93923841d38f0d5e2ec9d7
+       GtkWidget * scrollable_child = gtk_bin_get_child(GTK_BIN(info_scrolled.gobj()));
+       gtk_viewport_set_shadow_type(GTK_VIEWPORT(scrollable_child), GTK_SHADOW_NONE);
        this ->get_vbox() ->pack_start( info_scrolled ) ;
 
        //add label for detail and fill with relevant info