bug#10047: Looking for help debugging an undo issue

[Chong Yidong]

Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

> I've installed a patch which reduces align.el's use of markers a
> little bit.  It seems sufficient to get your test case to work, but I
> can't guarantee it will solve the problem in your more general case.
> It'd take a bit more analysis of align.el's code to figure out how to
> fix it further.

I fixed align-region to delete the temporary markers it uses.  This
seems to clear up the remaining problems.