bug#23869: 25.0.95; replace-match can crash emacs

[Stefan Monnier]

> The only alternative I'm aware of is to detect the clobbering and
> error out, as the patch I proposed does as "last line of defense".

Sounds fine, yes.

> Is that what you had in mind?

I didn't have anything specific in mind, but indeed it's typically the
approach I've taken so far in similar circumstances (e.g. detecting
when syntax-propertize modified the buffer and cry foul if so).


        Stefan