bug#67357: [PATCH] Fix c-ts-mode block indent when first-siblings are comments

[Eli Zaretskii <eliz@gnu.org>]

Ping! Ping!  Yuan, please chime is, as I'm waiting for your comments
before we install on the release branch.

This and other patches for TS-based modes are currently delaying the
release of Emacs 29.2, so please try to be more responsive, okay?

> Cc: noah.v.peart@gmail.com, 67357@debbugs.gnu.org, dmitry@gutov.dev
> Date: Wed, 29 Nov 2023 15:47:25 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> 
> > Date: Fri, 24 Nov 2023 16:46:32 +0200
> > From: Eli Zaretskii <eliz@gnu.org>
> > Cc: dmitry@gutov.dev, casouri@gmail.com, 67357@debbugs.gnu.org
> > 
> > > From: Noah Peart <noah.v.peart@gmail.com>
> > > Date: Fri, 24 Nov 2023 06:35:06 -0800
> > > Cc: dmitry@gutov.dev, casouri@gmail.com, 67357@debbugs.gnu.org
> > > 
> > > To reproduce the indentation bugs for unbracketed `else_clause`, and 
> > > do-while:
> > > 1. open a buffer and insert the following:
> > > 
> > >     int main() {
> > >       if (true) 
> > >         puts("Hello");
> > >       else 
> > >                     puts("No matched rule!"); // 1
> > >       do 
> > >         puts("Hello");
> > >                     while (indented_as_part_of_block);  // 2
> > >     }
> > > 
> > > 2. call `M-x example-setup` to configure `c-ts-mode`
> > > 3. `M-x indent-region` to indent the whole buffer
> > > You should see that the line with comment `1` has not been
> > > indented, and the line with comment `2` has been indented to the 
> > > same level as the previous line.
> > > 
> > > To reproduce the indentation bugs when comments are the first
> > > siblings:
> > > 1. open a buffer and insert:
> > > 
> > >     int main() {
> > >       while (true) { /* foo */
> > >                           if (true) { // 1
> > >                           puts ("Hello"); // 2
> > >        }
> > >       }
> > >     }
> > > 
> > > 2. call `M-x example-setup` to configure `c-ts-mode`
> > > 3. `M-x indent-region` to indent the whole buffer
> > > 
> > > You should see that the lines with comments `1` and `2` have
> > > not been indented at all.
> > 
> > Thanks, I see the problems now.
> > 
> > Let's wait for Yuan to chime in.
> 
> Yuan, could you please comment on the proposed solution?  TIA.
> 
> 
> 
>