bug#64128: regexp parser zero-width assertion bugs

[Mattias Engdegård]

21 juni 2023 kl. 08.08 skrev Paul Eggert <eggert@cs.ucla.edu>:

>> 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.

Good, it's now in master. Let's think about whether an error can be motivated, 
and how.
We usually don't prevent the user to do silly things, except when there is a 
strong reason to believe that it might be a serious mistake.