bug#51762: 13.0.14; environment formating

[Ikumi Keita]

>>>>> Ikumi Keita <ikumi@ikumi.que.jp> writes:
> I think the attached patch fixes the problem. Could you test whether it
> works on your side?

Hmm, the patch also fails to identify the following form of code
comment:
 \\% This is a code comment.
That is, a line beginning with 0 or more whitespaces, followed by even
number of back slashes, followed by percent sign(s) and comment body.

Maybe we should give up regexp-based approach to find out code comments
accurately.

Regards,
Ikumi Keita