bug#64128: regexp parser zero-width assertion bugs

[Paul Eggert]

On 2023-06-20 04:36, Mattias Engdegård wrote:

> Sounds fine, with the option to go full error on group B if we agree that 
> that's even better.

That would be fine too. I'd even prefer it. In the meantime your patch 
looks good.


> I still think the whole chapter needs a reform from the sheer weight of organic growth over the 
> years. In particular, the division between "regexp special" and "regexp 
> backslash" is purely syntactical, not semantic, and groups things in the wrong way.

Agreed.