bug#43941: HTML+ mode: dangerous apostrophe after fullwidth parenthesis

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: Stephen Berman <stephen.berman@gmx.net>,  jidanni@jidanni.org,
>   43941@debbugs.gnu.org
> Date: Mon, 12 Oct 2020 18:17:41 +0200
> 
> >> But the face does not change if `(' is used instead of `（', e.g. copy
> >> the following two lines into a buffer and type `M-x html-mode' (or `M-x
> >> mhtml-mode', the face change appears in both):
> >
> > So which of them is a bug?
> 
> In the context of the OP it seems clear that string face is wrong.  So
> in my simpler example, that means the display of the second line
> containing FULLWIDTH LEFT PARENTHESIS is buggy.

Do the ASCII parentheses have some syntactic significance in this
context, then?  If not, why do the parentheses affect the meaning of
the apostrophe?