Re: :alnum: broken?

[Paul Eggert]

On 2/26/20 7:48 AM, Stefan Monnier wrote:
> FWIW, you have a +1 from me, tho I don't see any urgency so I'd keep it
> for `master`.

I agree with Stefan on both points.

The bug noted by Andreas should also be fixed. More specifically, I 
suggest having Emacs diagnose the typo only when GNU grep diagnoses it, 
as it's better to be consistent among GNU applications. Grep diagnoses 
the contents of [...] if all the following are true:

  * The first character is ":".
  * The last character is ":".
  * There is some non-":" character.
  * There are no ranges, char/equiv classes or collation elements.

GNU grep has done this for about a decade and this has worked well. If 
we don't like these rules we can change them but I would then suggest we 
also change GNU grep to be consistent.