bug#56256: Emacs 28.1 gets stuck when typing some C++ code

[Iru Cai]

On 2022/6/29 00:28, Alan Mackenzie wrote:
> I think the following patch should fix it.  Could you try it out on your
> real C++ code, please, and tell us whether the bug is actually fixed.
> (If you want any help with applying the patch or byte compiling CC Mode
> afterwards, feel free to send me private email.):

Thanks, this fixes this bug, and I haven't found a issue when editing 
some of my C++ code.

> diff -r 03c932b2922b cc-fonts.el
> --- a/cc-fonts.el       Sat Jun 18 15:40:47 2022 +0000
> +++ b/cc-fonts.el       Tue Jun 28 16:15:37 2022 +0000
> @@ -1823,7 +1823,7 @@
>     ;; font-lock-keyword-face.  It always returns NIL to inhibit this and
>     ;; prevent a repeat invocation.  See elisp/lispref page "Search-based
>     ;; Fontification".
> -  (let (mode capture-default id-start id-end declaration sub-begin sub-end)
> +  (let (mode capture-default id-start id-end declaration sub-begin sub-end tem)
>       (while (and (< (point) limit)
>                 (search-forward "[" limit t))
>         (when (progn (backward-char)
> @@ -1835,15 +1835,18 @@
>                         (char-after)))
>         ;; Is the first element of the list a bare "=" or "&"?
>         (when mode
> -         (forward-char)
> -         (c-forward-syntactic-ws)
> -         (if (memq (char-after) '(?, ?\]))
> -             (progn
> -               (setq capture-default mode)
> -               (when (eq (char-after) ?,)
> -                 (forward-char)
> -                 (c-forward-syntactic-ws)))
> -           (c-backward-token-2)))
> +         (setq tem nil)
> +         (save-excursion
> +           (forward-char)
> +           (c-forward-syntactic-ws)
> +           (if (memq (char-after) '(?, ?\]))
> +               (progn
> +                 (setq capture-default mode)
> +                 (when (eq (char-after) ?,)
> +                   (forward-char)
> +                   (c-forward-syntactic-ws))
> +                 (setq tem (point)))))
> +         (if tem (goto-char tem)))
>   
>   	;; Go round the following loop once per captured item.  We use "\\s)"
>         ;; rather than "\\]" here to avoid infinite looping in this situation: