Window background color

[David Reitter]

How does one set the background color of a window?

I use `face-remapping-alist' to define a `default' face for a buffer,  
with a specific background color.  This works fine unless the buffer  
is small and does not fill the whole window, or if I scroll to the  
end.  The area between the last line of the buffer and the bottom of  
the window is drawn in the frame's background color, rather than in  
the background color assigned with the default face in that buffer.

(I see this in a 23 CVS (Cocoa port) build.)

It appears that only a frame parameter is used and that the frame is  
cleared using a rif->clear_frame_area call, which is not specific to  
windows.  I haven't found the right fix for this so far.  Would it be  
sensible to change clear_frame_area to establish the right background  
color, i.e. the one associated with the default face appropriate for  
the buffer shown in the window (updated_window), and only default to  
the frame's background?