bug#8679: 24.0.50; wrong isearch highlighting for mismatch

[Drew Adams]

> > Not sure there is an easy fix for this one.  And it's not very
> > important.  But worth logging for future reference, at least.
> 
> Currently it has exactly the same behavior as you asked in
> http://thread.gmane.org/gmane.emacs.devel/74539/focus=74614

Not as I _asked_, but as I _stated_ was probably "as good as it gets".  To which
I added, "but I'm open, if someone has a better idea".  I said "I don't know how
to fix that."

Actually, I forgot about that bug thread.  ;-)

This time I'm saying something similar, but the use case is different.  What I
said before is still true, but this report is about the behavior after `M-e', so
the consideration about a buffer change doesn't really apply.

IOW, both observations are relevant, I think.  For this use case (same buffer
where `M-e' was used), it might be good if after editing the matching part were
not highlighted as a mismatch.  Again, dunno whether that would be an easy fix -
I doubt it, but maybe you have an idea.

I have no good idea about this.  Do you?