Re: [RFC/PATCH] Fix path prefixing in grep_object

[Jeff King <peff@peff.net>]

On Sat, Aug 24, 2013 at 09:35:58PM -0400, Phil Hord wrote:

> When the pathspec given to grep includes a tree name, the full
> name of matched files is assembled using colon as a separator.
> If the pathspec includes a tree name, it should use a slash
> instead.
> 
> Check if the pathspec already names a tree and ref (including
> a colon) and use a slash if so.

Makes sense.

> I'm not sure about the detection I used here.  It works, but it is
> not terribly robust.  Is there a better way to handle this?  Maybe
> something like 'prefix_pathspec(name,"");'.

I think the information you want has been thrown away by the time we get
to grep_object. Only get_sha1 knows whether the name was really a direct
tree reference or if it had to traverse paths.

So we are necessarily reconstructing based on what we know of the
syntax. And I think that your rule is OK, because we know that refnames
cannot contain a colon. So even though pathnames can, we do not have to
care; we only want to know "is there a path in the name", and if we have
at least one colon, the answer is yes.

>  builtin/grep.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

A test would be nice. Both to make sure we do not re-break it, and because
it helps demonstrate the problem very easily (it took me a minute to
figure out what was going on from your description).

> diff --git a/builtin/grep.c b/builtin/grep.c
> index 03bc442..d0deae4 100644
> --- a/builtin/grep.c
> +++ b/builtin/grep.c
> @@ -480,8 +480,9 @@ static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
>  		len = name ? strlen(name) : 0;
>  		strbuf_init(&base, PATH_MAX + len + 1);
>  		if (len) {
> +			int has_colon = !!strchr(name,':');
>  			strbuf_add(&base, name, len);
> -			strbuf_addch(&base, ':');
> +			strbuf_addch(&base, has_colon?'/':':');

Please use whitespace with your ternary operator. The '/':':' made me
think I was reading Perl for a minute. :)

-Peff