bug#73900: 30.0.91; auto-fill adds extra space in js-ts-mode

[Dmitry Gutov]

On 27/10/2024 12:55, Eli Zaretskii wrote:
> > From: Michael Kleehammer<michael@kleehammer.com>
> > Date: Sat, 19 Oct 2024 22:46:55 -0500
> >
> > In Emacs 30, js-ts-mode auto-fill chooses an incorrect prefix when
> > wrapping comments.
> >
> > 1) emacs -Q
> >
> > 2) In the scratch buffer:
> >     a) M-x js-ts-mode
> >     b) M-x auto-fill-mode
> >     c) M-x erase-buffer
> >     
> > 3) Paste in a long JS comment:
> >
> >     // This buffer is for text that is not saved, and for Lisp evaluation.  To 
> > create a file, visit it
> >
> > 4) At end of line, press <Space>.
> >
> > The text wraps like so:
> >
> >     // This buffer is for text that is not saved, and for Lisp evaluation.
> >     //   To create a file, visit it
> >
> > In previous versions, it would wrap like so:
> >
> >     // This buffer is for text that is not saved, and for Lisp evaluation.
> >     // To create a file, visit it
> Adding people who know about js-ts-mode, in the hope they will have
> comments or suggestions.

I suppose the answer is somewhere around the fact that we have both 
normal-auto-fill-function and fill-paragraph-function, and that 
js-ts-mode (through c-ts-common-comment-setup) only configures the 
latter, while js-mode (in js--mode-setup) has settings for both.

Not sure why the default do-auto-fill doesn't skip over the space, though.