Reverting to stable from test

[William Morris <wrm@innovation-tk.com>]

Is test broken?  I don't know if this is normal, but...

I just installed ntp.  Unfortunately, I had the test archive in my
source list instead of just stable (I installed X 4.0.? a while
back from test and then forgot to remove the entry from the source
list).

In the course of installing ntp, apt updated my C development stuff.
Now upon compiling applications that compiled cleanly before, I get
pages of warnings and failures.  For example:

In file included from /usr/include/linux/affs_fs_i.h:7,
                 from /usr/include/linux/fs.h:289,
                 from /usr/include/linux/capability.h:17,                 
		 from /usr/include/linux/binfmts.h:5,
		 from /usr/include/linux/sched.h:9,
	         from /usr/include/linux/mm.h:4,
		 from /usr/include/linux/slab.h:14,
		 from /usr/include/asm/pci.h:24,
	         from /usr/include/linux/pci.h:591,
		 from pci_device.c:41:
/usr/include/linux/time.h:108: warning: `FD_SET' redefined
/usr/include/sys/select.h:83: warning: this is the location of the
previous definition
/usr/include/linux/time.h:109: warning: `FD_CLR' redefined
/usr/include/sys/select.h:84: warning: this is the location of the
previous definition
                 <snip>

This is annoying!  There are other things that are similarly broken.


How can I revert my system to its state before the upgrade?  Is there
a simple way to get rid of all test stuff and revert to stable
stuff (excluding the Xserver if possible)?

Thanks in advance
-- 
William Morris
wrm@innovation-tk.com