Re: Scan of regexps in Emacs (March 17)

[Eli Zaretskii]

> From: Paul Eggert <address@hidden>
> Date: Tue, 2 Apr 2019 15:08:43 -0700
> Cc: Stefan Monnier <address@hidden>, address@hidden
> 
> > (Do we have any latitude at all for changing even obscure corners of
> > regexp syntax and semantics today?)
> 
> I would say so, certainly for the raw 8-bit-bytes in ranges stuff (where
> nobody knows what they mean or even should mean), and possibly even for
> some of the other rarely-used and questionable uses.

Beware: Emacs sometimes does use regexps when dealing with unibyte
buffers and strings, where these ranges could be significant.  So I'd
suggest a careful audit of such places, to see whether raw bytes
could be an issue, because the resulting breakage could be subtle and
not become apparent until much later.