Re: Two bugs in --pretty with %C(auto)

["René Scharfe" <l.s.r@web.de>]

Am 17.09.2016 um 20:25 schrieb René Scharfe:
> diff --git a/pretty.c b/pretty.c
> index 9788bd8..493edb0 100644
> --- a/pretty.c
> +++ b/pretty.c
> @@ -1072,6 +1072,8 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
>  	case 'C':
>  		if (starts_with(placeholder + 1, "(auto)")) {
>  			c->auto_color = want_color(c->pretty_ctx->color);
> +			if (c->auto_color)
> +				strbuf_addstr(sb, GIT_COLOR_RESET);
>  			return 7; /* consumed 7 bytes, "C(auto)" */
>  		} else {
>  			int ret = parse_color(sb, placeholder, c);

We could optimize this a bit (see below).  I can't think of a downside;
someone adding a prefix would be responsible for adding a reset as well
if needed, right?

-- >8 --
Subject: [PATCH] pretty: avoid adding reset for %C(auto) if output is empty

We emit an escape sequence for resetting color and attribute for
%C(auto) to make sure automatic coloring is displayed as intended.
Stop doing that if the output strbuf is empty, i.e. when %C(auto)
appears at the start of the format string, because then there is no
need for a reset and we save a few bytes in the output.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
---
Reverts the change to t6006, so we'd need another test for this.
Anatoly? :)

 pretty.c                   | 2 +-
 t/t6006-rev-list-format.sh | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pretty.c b/pretty.c
index 493edb0..25efbca 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1072,7 +1072,7 @@ static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
 	case 'C':
 		if (starts_with(placeholder + 1, "(auto)")) {
 			c->auto_color = want_color(c->pretty_ctx->color);
-			if (c->auto_color)
+			if (c->auto_color && sb->len)
 				strbuf_addstr(sb, GIT_COLOR_RESET);
 			return 7; /* consumed 7 bytes, "C(auto)" */
 		} else {
diff --git a/t/t6006-rev-list-format.sh b/t/t6006-rev-list-format.sh
index f6020cd..a1dcdb8 100755
--- a/t/t6006-rev-list-format.sh
+++ b/t/t6006-rev-list-format.sh
@@ -225,7 +225,7 @@ test_expect_success '%C(auto,...) respects --color=auto (stdout not tty)' '
 
 test_expect_success '%C(auto) respects --color' '
 	git log --color --format="%C(auto)%H" -1 >actual &&
-	printf "\\033[m\\033[33m%s\\033[m\\n" $(git rev-parse HEAD) >expect &&
+	printf "\\033[33m%s\\033[m\\n" $(git rev-parse HEAD) >expect &&
 	test_cmp expect actual
 '
 
-- 
2.10.0