Re: [PATCH 1/1] freshen_file(): use NULL `times' for implicit current-time

[Junio C Hamano <gitster@pobox.com>]

luciano.rocha@booking.com writes:

> Update freshen_file() to use a NULL `times', semantically equivalent to
> the currently setup, with an explicit `actime' and `modtime' set to the
> "current time", but with the advantage that it works with other files
> not owned by the current user.
>
> Fixes an issue on shared repos with a split index, where eventually a
> user's operation creates a shared index, and another user will later do
> an operation that will try to update its freshness, but will instead
> raise a warning:
>   $ git status
>   warning: could not freshen shared index '.git/sharedindex.bd736fa10e0519593fefdb2aec253534470865b2'

A couple of questions:

 - Does utime(fn, NULL) work for any non-owner user, or does the
   user need to have write access to it?

 - If the answer is not "you need to be able to write", doesn't the
   bug lie elsewhere, namely, why .git/sharedindex.* not writable by
   the current user, if it is a shared repository setting?

Thanks.

> Signed-off-by: Luciano Miguel Ferreira Rocha <luciano.rocha@booking.com>
> ---
>  sha1-file.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/sha1-file.c b/sha1-file.c
> index 6926851724..ccd34dd9e8 100644
> --- a/sha1-file.c
> +++ b/sha1-file.c
> @@ -881,9 +881,7 @@ void prepare_alt_odb(struct repository *r)
>  /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
>  static int freshen_file(const char *fn)
>  {
> -	struct utimbuf t;
> -	t.actime = t.modtime = time(NULL);
> -	return !utime(fn, &t);
> +	return !utime(fn, NULL);
>  }
>  
>  /*