impress / trivial crash after undo ...

        IIRC this was a HardHack, and what a rats nest it seems to be:

        https://bugs.freedesktop.org/show_bug.cgi?id=34548

        I have an horrible hack around it ;-) IMHO the design and attempt to
track those ordinals looks fragile, over-optimised and generally
problematic. My guess would be that a better data structure might make
things simpler & faster; if we could work out what that looked like:
presumably with a more sensible lifecycle mechanism, and perhaps leaving
undo objects in the page, but making them invisible might work better
(?) - with a plain list of refs for ultimate removal when pruning the
undo queue size (?).

        Anyhow - thoughts / better fixes much appreciated.

        ATB,

                Michael.

-- 
michael.meeks@suse.com  <><, Pseudo Engineer, itinerant idiot