bug#64019: 29.0.91; Fix some tree-sitter :match regexps

[Mattias Engdegård]

17 juni 2023 kl. 08.48 skrev Andreas Schwab <schwab@linux-m68k.org>:

>>> -                              (:match "\\`?[#\"'`:?]" @char))
>>> +                              (:match "\\`\\?[#\"'`:?]" @char))
>> 
>> I don't mind, but it seems like both versions do the same thing:

Interesting! Now as Andreas says,

> This depends on `?' being treated as an ordinary character if occuring
> in a context where the special meaning does not make sense, which is
> poor practice.

which is quite right and that `?` should indeed be escaped for style reasons if 
nothing else.
However there appears to be a hitherto unknown parsing bug in the Emacs regexp 
parser here.
(And in xr, which has the ambition to be mostly bug-compatible with Emacs.)

I'll open a new bug about it.