Subject: Re: [PATCH 5/8] combine-diff: move show_log_first logic/action out of paths scanning

From: Junio C Hamano <[email-masked]>
Date: Mon, 03 Feb 2014 15:21:13 -0800

Kirill Smelkov <[email-masked]> writes:

> Judging from sample outputs and tests nothing changes in diff -c output,

Yuck.

I do not think the processing done inside the loop for the first
path (i.e. i==0) before we call show_log(rev) affects what that
called show_log(rev) does, so it probably is a good readability
change.

Thanks.

> and this change will help later patches, when we'll be refactoring paths
> scanning into its own function with several variants - the
> show_log_first logic / code will stay common to all of them.
>
> NOTE: only now we have to take care to explicitly not show anything if
>     parents array is empty, as in fact there are some clients in Git code,
>     which calls diff_tree_combined() in such a way.
>
> Signed-off-by: Kirill Smelkov <[email-masked]>
> ---
>  combine-diff.c | 24 ++++++++++++++----------
>  1 file changed, 14 insertions(+), 10 deletions(-)
>
> diff --git a/combine-diff.c b/combine-diff.c
> index a03147c..272931f 100644
> --- a/combine-diff.c
> +++ b/combine-diff.c
> @@ -1313,6 +1313,20 @@ void diff_tree_combined(const unsigned char *sha1,
>  	struct combine_diff_path *p, *paths = NULL;
>  	int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
>  
> +	/* nothing to do, if no parents */
> +	if (!num_parent)
> +		return;
> +
> +	show_log_first = !!rev->loginfo && !rev->no_commit_id;
> +	needsep = 0;
> +	if (show_log_first) {
> +		show_log(rev);
> +
> +		if (rev->verbose_header && opt->output_format)
> +			printf("%s%c", diff_line_prefix(opt),
> +			       opt->line_termination);
> +	}
> +
>  	diffopts = *opt;
>  	copy_pathspec(&diffopts.pathspec, &opt->pathspec);
>  	diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
> @@ -1321,8 +1335,6 @@ void diff_tree_combined(const unsigned char *sha1,
>  	/* tell diff_tree to emit paths in sorted (=tree) order */
>  	diffopts.orderfile = NULL;
>  
> -	show_log_first = !!rev->loginfo && !rev->no_commit_id;
> -	needsep = 0;
>  	/* find set of paths that everybody touches */
>  	for (i = 0; i < num_parent; i++) {
>  		/* show stat against the first parent even
> @@ -1338,14 +1350,6 @@ void diff_tree_combined(const unsigned char *sha1,
>  		diffcore_std(&diffopts);
>  		paths = intersect_paths(paths, i, num_parent);
>  
> -		if (show_log_first && i == 0) {
> -			show_log(rev);
> -
> -			if (rev->verbose_header && opt->output_format)
> -				printf("%s%c", diff_line_prefix(opt),
> -				       opt->line_termination);
> -		}
> -
>  		/* if showing diff, show it in requested order */
>  		if (diffopts.output_format != DIFF_FORMAT_NO_OUTPUT &&
>  		    opt->orderfile) {