I have been using cfg-update quite happily for a good while.
I appreciate its automatically doing "simple" updates.

For any that it can't do automatically, I have done them manually
(using emacs/ediff). I decided to try meld instead (I use gnome).

It does make everything clear, but something seems wrong. Cfg-update
keeps a backup containing the previous version of the file. When
cfg-update invokes meld, the three relevant versions are displayed
in meld's window like this

current backup new (._*)

I believe I want the final state to be
backup = current
and
current = merger of current and new

But current and new are not adjacent on the meld so I don't see how to
do this using the fancy meld mouse actions. It seems to me, I want meld
to display

backup current new

then, for each change that I want from new, I push new version to
current.
But I don't see how to have cfg-update call meld in this order and I
don't see how to have meld swap the two left panes.
(I am assuming that cfg-update will arrange that when I am finished
backup = current-before-meld.
If not, I can do this in meld)

Can someone tell me how to get the configuration I want or explain why
the configuration I get is actually what I (should) want.

thanks,
allan