Problem with CSS style options

[Jon Zabala Gutiérrez <judixzg hotmail com>]

Hi all,

I am creating an application in Ubuntu using Gtkmm libraries, and I have a problem with the CSS style 
properties.

I started the application using Gtkmm 3.0 that at that moment included Gtk 3.2 library.

In the GtkCssProvider reference it says for the style supported property background-repeat:

If not specified, the style doesn't respect the CSS3 specification, since the background will be stretched to 
fill the area.

That is the behavior I wanted, so I didn't specify this property.

This application is intended to be run in a custom hardware created by another company so I have installed 
the latest Gtk libraries in order to run the application, but they turned to be the version 3.4. In this 
version it seems that the previous behavior has changed and now works as follows, if you don't specify 
background-repeat, by default is applied "repeat". If you specify "no-repeat" then the image is not stretched 
to fill the area.

CSS3 says that, in order to get the image stretched, you must use the property background-size with a value 
of 100%, but this property is not supported by Gtk.

Do you know how can I achieve the desired behavior?

Thanks a lot in advance,

Jon Zabala