Re: [PATCH v4 09/21] range-diff: adjust the output of the commit pairs

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> This change brings `git range-diff` yet another step closer to
> feature parity with tbdiff: it now shows the oneline, too, and indicates
> with `=` when the commits have identical diffs.
> 
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>  range-diff.c | 64 ++++++++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 55 insertions(+), 9 deletions(-)
> 
> diff --git a/range-diff.c b/range-diff.c
> index 1ecee2c09..8329f52e7 100644
> --- a/range-diff.c
> +++ b/range-diff.c
> @@ -7,6 +7,8 @@
>  #include "xdiff-interface.h"
>  #include "linear-assignment.h"
>  #include "diffcore.h"
> +#include "commit.h"
> +#include "pretty.h"
>  
>  struct patch_util {
>  	/* For the search for an exact match */
> @@ -255,9 +257,54 @@ static void get_correspondences(struct string_list *a, struct string_list *b,
>  	free(b2a);
>  }
>  
> -static const char *short_oid(struct patch_util *util)
> +static void output_pair_header(struct strbuf *buf,
> +			       struct strbuf *dashes,
> +			       struct patch_util *a_util,
> +			       struct patch_util *b_util)
>  {
> -	return find_unique_abbrev(&util->oid, DEFAULT_ABBREV);
> +	struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
> +	struct commit *commit;
> +
> +	if (!dashes->len)
> +		strbuf_addchars(dashes, '-',
> +				strlen(find_unique_abbrev(oid,
> +							  DEFAULT_ABBREV)));
> +
> +	strbuf_reset(buf);
> +	if (!a_util)
> +		strbuf_addf(buf, "-:  %s ", dashes->buf);
> +	else
> +		strbuf_addf(buf, "%d:  %s ", a_util->i + 1,
> +			    find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));

> +	if (!a_util)
> +		strbuf_addch(buf, '>');
> +	else if (!b_util)
> +		strbuf_addch(buf, '<');
> +	else if (strcmp(a_util->patch, b_util->patch))
> +		strbuf_addch(buf, '!');
> +	else
> +		strbuf_addch(buf, '=');
> +
> +	if (!b_util)
> +		strbuf_addf(buf, " -:  %s", dashes->buf);
> +	else
> +		strbuf_addf(buf, " %d:  %s", b_util->i + 1,
> +			    find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));