Subject: Re: bug#52349: 29.0.50; vc-git and diff-mode: stage hunks

From: Dmitry Gutov <[email-masked]>
Date: Wed, 24 Aug 2022 23:20:59 +0300

On 24.08.2022 21:20, Juri Linkov wrote:
>>>> Perhaps we should also check that there are no existing staged changes for
>>>> those files, and if so, abort? This way we won't commit anything else by
>>>> accident.
>>> Will do later.
>> Shouldn't be too hard, if we don't try to do it eagerly. Just add a check
>> inside (when vc-git-patch-string ...) in vc-git-checkin.
> This uses the same command `git diff --cached --quiet` as in commit-patch
> that you mentioned earlier
> https://github.com/caldwell/commit-patch/blob/master/commit-patch#L215-L217
> (but with an error message shorter than "Cowardly refusing to do anything
> potentially harmful":)
> 
> diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
> index 8458b40714..fa09ecf472 100644
> --- a/lisp/vc/vc-git.el
> +++ b/lisp/vc/vc-git.el
> @@ -944,6 +944,8 @@ vc-git-checkin
>                 (let ((default-directory (file-name-directory file1)))
>                   (make-nearby-temp-file "git-msg")))))
>       (when vc-git-patch-string
> +      (unless (eq (vc-git-command nil t nil "diff" "--cached" "--quiet") 0)
> +        (error "Index not empty"))

user-error, maybe?

>         (let ((patch-file (make-temp-file "git-patch")))
>           (with-temp-file patch-file
>             (insert vc-git-patch-string))

Looking great otherwise. Please install whenever you think it's ready.