Re: [PATCH v2 1/3] breaking-changes: deprecate support for core.commentString=auto

> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> When "core.commentString" is set to "auto" then "git commit" will
> automatically select the comment character ensuring that it is not the
> first character on any of the lines in the commit message. This was
> introduced by commit 84c9dc2c5a2 (commit: allow core.commentChar=auto
> for character auto selection, 2014-05-17) The motivation seems to be

> to avoid commenting out lines from the existing message when amending
> a commit that was created with a message from a file.
>
> Unfortunately this feature does not work with:
>
>  * commit message templates that contain comments.
>
>  * prepare-commit-msg hooks that introduce comments.
>
>  * "git commit --cleanup=strip --edit -F <file>" which means that it
>    is incompatible with
>
>    - the "fixup" and "squash" commands of "git rebase -i" as the
>      comments added by those commands are then treated as part of
>      the commit message.
>
>    - the conflict comments added to the commit message by "git
>      cherry-pick", "git rebase" etc. as these comments are then
>      treated as part of the commit message.
>
> It is also ignored by "git notes" when amending a note.
>
> The issues with comments coming from a template, hook or file are a
> consequence of the design of this feature and are therefore hard to
> fix.
>
> As the costs of this feature outweigh the benefits deprecate it and

> remove it in Git 3.0. If someone comes up with some patches that fix
> all the issues in a maintainable way then I'd be happy to see this
> change reverted.
>
> The next commits will add a warning and some advice for users on how
> they can update their config settings.
>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---
>  +
> -If set to "auto", `git-commit` would select a character that is not
> +ifndef::with-breaking-changes[]
> +If set to "auto", `git-commit` will select a character that is not
>  the beginning character of any line in existing commit messages.
> -+
> +Support for this value is deprecated and will be removed in Git 3.0
> +due to the following limitations:
> ++
> +--
> +* It is incompatible with adding comments in a commit message
> +  template. This includes the conflicts comments added to
> +  the commit message by `cherry-pick`, `merge`, `rebase` and
> +  `revert`.
> +* It is incompatible with adding comments to the commit message
> +  in the `prepare-commit-msg` hook.
> +* It is incompatible with the `fixup` and `squash` commands when
> +  rebasing,
> +* It is not respected by `git notes`
> +--
> ++
> +endif::with-breaking-changes[]