RE: question about markers, replace-match, and undo

[Drew Adams]

> > Can you send a program to construct the test case that fails for you?
> > Then I will test my patch and make sure it fixes your problem.
> 
Johan> I tested it like this:
...

What Johan did is essentially what I did, so I think this is fixed. Thanks.

What I did (see my initial report):

emacs -Q
type mnopqrs in a buffer
C-SPC at (before) m
C-SPC after s
C-s mnopqrs RET
(replace-match "ABC")
C-_
Look at mark-ring and (mark).

I also reported a bug (?) about `buffer-has-markers-at'. In this case, even 
though the bugged result above is two markers before m and no marker after s, 
`buffer-has-markers-at' returns t for the position after s.