Strange gnome-config output

[Sydney Weidman <Sydney_Weidman mbnet mb ca>]

When I run 'gnome-config --cflags idl glib gtk' the output is:


	-I/usr/share/idl -I/usr/lib/glib/include -I/usr/X11R6/include

But when I run 'gnome-config --cflags glib gtk idl' the output is:

	-I/usr/share/idl

Is this the expected value? If so, why does reversing the order of the
include tags change the include requirements? Are the includes from glib
and gtk included in the includes from /usr/share/idl?

Sorry if this is simple-minded. Some of this stuff doesn't make sense to
me.

TIA

Cheers,
Syd.