bug#34975: 26.1.92; In backquote, the comma marker does not work with variable name started with dot

[Noam Postavsky]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Noam Postavsky <npostavs@gmail.com>
>> Date: Wed, 03 Apr 2019 23:31:24 -0400
>> Cc: Xu Chunyang <mail@xuchunyang.me>, 34975@debbugs.gnu.org
>> 
>> There's also Bug#19790 about this.  I think it makes sense to just
>> remove this reader macro, as far as I can tell, nobody really wants this
>> destructive splicing feature.
>
> How hard would it be fixing it?  I'm uneasy with removing features
> because we are confused about them.

The destructive splicing feature was never added though.  Only the
reader macro part.  But if you're asking about possible breakage, then
yes, it's possible that someone out there wrote a macro which gives some
semantics to ",.", like pcase gives its own semantics to "`" and ",".