bug#55780: 29.0.50; byte-compile-docstring-style-warn warns against valid usages of curved quotes

[Eliza Velasquez]

The elisp manual states in "(elisp)Documentation Tips"

> When a documentation string refers to a Lisp symbol, write it as it
> would be printed (which usually means in lower case), surrounding it
> with curved single quotes (‘..’).

‘checkdoc’ treats this case as valid.

Recently, though, it seems like bytecomp.el’s
‘byte-compile-docstring-style-warn’ function was recently modified by
2701cd59b521989530a7eb7489540c64177e0f69 which mistakenly flags this
usage as incorrect. Its news entry states:

> When writing code snippets that contains the ' character (APOSTROPHE),
> that quote character has to be escaped to avoid Emacs displaying it as
> ’ (LEFT SINGLE QUOTATION MARK), which would make code examples like
> 
>     (setq foo '(1 2 3))
> 
> invalid.  Emacs will now warn during byte compilation if it seems
> something like that, and also warn about when using RIGHT/LEFT SINGLE
> QUOTATION MARK directly.  In both these cases, if these characters
> should really be present in the doc string, they should be quoted with
> \=.

Judging by both this news entry and the implementation's regex, I assume
this is intended to catch erroneous cases like “(setq foo ’(1 2 3))” and
allow correct usages like “it’s”, but it inadvertently flags cases like
“‘lisp-mode’”.

In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.33, cairo 
version 1.16.0)
Repository revision: e06d600b4963fc6ccc69fb0bbbc725350a80c9fc
Repository branch: master
System Description: NixOS 22.11 (Raccoon)

Configured using:
 'configure
 
--prefix=/nix/store/banascjwdai200brq116c4m54jx10if9-emacs-pgtk-native-comp-20220529.0
 --disable-build-details --with-modules --with-x-toolkit=gtk3
 --with-cairo --with-native-compilation --with-pgtk'

-- 
Eliza