Greek Polytonic and GTK+ IM problems

[Simos Xenitellis <simos74 gmx net>]

I try to get GTK+ IM (native) to type Greek Polytonic and I have some
problems.

The way I do it is to add to 
http://cvs.gnome.org/viewcvs/gtk%2B/gtk/gtkimcontextsimple.c?view=markup
in the 
static const guint16 gtk_compose_seqs[] {}
the following:
  GDK_dead_horn,        GDK_Greek_alpha,        0,      0,      0,     
0x1f00,   GDK_dead_horn,        GDK_Greek_epsilon,      0,      0,     
0,      0x1f10,
  GDK_Multi_key,        GDK_greater,            GDK_Greek_alpha,       
0,      0,      0x1f00,
  GDK_Multi_key,        GDK_greater,            GDK_Greek_epsilon,     
0,      0,      0x1f10

(The above are an example to allow typing just two letters: á and  á).
I compile gtk+ 2.7.0 (cvs), install, test but I do not get the above
characters.

Any hints on what to do to get this working?

Simos