Re: [PATCH] replace: fix replacing object with itself

[Jeff King <peff@peff.net>]

On Sun, Nov 09, 2014 at 01:05:31AM +0100, Manzur Mukhitdinov wrote:

> When object is replaced with itself git shows unhelpful messages like(git log):
>     "fatal: replace depth too high for object <SHA1>"
> 
> Prevents user from replacing object with itself(with test for checking
> this case).

I thought we already did this in the last round of git-replace patches,
but it looks like we only did it for the newly added --edit and --graft
cases, not "git replace X X". I think this is probably a good step. I've
also considered that this should be another way of deleting the
replacement, but I think we decided that was too magical.

> diff --git a/builtin/replace.c b/builtin/replace.c
> index 294b61b..b7e05ad 100644
> --- a/builtin/replace.c
> +++ b/builtin/replace.c
> @@ -186,6 +186,9 @@ static int replace_object(const char *object_ref, const char *replace_ref, int f
>  	if (get_sha1(replace_ref, repl))
>  		die("Failed to resolve '%s' as a valid ref.", replace_ref);
>  
> +	if (!hashcmp(object, repl))
> +		return error("new object is the same as the old one: '%s'", sha1_to_hex(object));
> +
>  	return replace_object_sha1(object_ref, object, replace_ref, repl, force);

I think all of the callers of replace_object_sha1 do this same check
now. Can we just move the check into that function instead of adding
another instance of it?

-Peff