Re: [PATCH 2/6] sha1_file: always allow relative paths to alternates

[Jeff King <peff@peff.net>]

On Sun, Oct 02, 2016 at 11:07:39AM +0200, René Scharfe wrote:

> diff --git a/builtin/count-objects.c b/builtin/count-objects.c
> index ba92919..b2afe36 100644
> --- a/builtin/count-objects.c
> +++ b/builtin/count-objects.c
> @@ -73,6 +73,12 @@ static int count_cruft(const char *basename, const char *path, void *data)
>  	return 0;
>  }
>  
> +static int print_alt_odb(struct alternate_object_database *alt, void *data)
> +{
> +	puts(alt->base);
> +	return 0;
> +}

This turns out to be wrong, because alt->base _isn't_ just the base;
it's also the scratch buffer we write into to form pathnames. So if
we've used the buffer to look up an object, we'll get that object name
here, not just the base.

It tends to work for your command because we do nothing except list the
alternates and exit, but I'm not sure if there are code paths which
might access an object.

I think giving a known state to the callback should be the
responsibility of foreach_alt_odb(), though.

-Peff