Re: [PATCH] checkout: add 'pre-checkout' hook

From: Jeff King <peff@peff.net>
Date: Oct 14, 2009, 05:13 UTC
Message-ID: <20091014051319.GF31810@coredump.intra.peff.net>
In-Reply-To: <1255495525-11254-1-git-send-email-sam.vilain@catalyst.net.nz>

On Wed, Oct 14, 2009 at 05:45:25PM +1300, Sam Vilain wrote:

> Add a simple hook that will run before checkouts.

What is the use case that makes it useful as a hook, and not simply as something people can do before running checkout?

I guess you can use it to block a checkout, but only after finding out _what_ you are going to checkout, but an exact use case escapes me.

Show 5 quoted lines

> -post-checkout
> -~~~~~~~~~~~~~
> -
> -This hook is invoked when a 'git-checkout' is run after having updated the
> +This hook is invoked when a 'git-checkout' is run after before updating the

Did you mean "before having" here?

Show 11 quoted lines

>  worktree.  The hook is given three parameters: the ref of the previous HEAD,
>  the ref of the new HEAD (which may or may not have changed), and a flag
>  indicating whether the checkout was a branch checkout (changing branches,
>  flag=1) or a file checkout (retrieving a file from the index, flag=0).
> -This hook cannot affect the outcome of 'git-checkout'.
> +This hook can prevent the checkout from proceeding by exiting with an
> +error code.
>  
>  It is also run after 'git-clone', unless the --no-checkout (-n) option is
>  used. The first parameter given to the hook is the null-ref, the second the
>  ref of the new HEAD and the flag is always 1.

Should this "after" in the bottom paragraph perhaps become "during"?

-Peff