Re: FW: Git log --graph doesn't output color when redirected

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

Jeff King <peff@peff.net> writes:

> On Sat, Dec 15, 2012 at 10:23:10AM +0700, Nguyen Thai Ngoc Duy wrote:
>
>> On Thu, Dec 13, 2012 at 8:13 PM, Jeff King <peff@peff.net> wrote:
>> > If you are using --format="%C(red)" or similar placeholders,
>> > they are the odd duck by not respecting the auto-color mode.
>> 
>> But they should, shouldn't they? Just asking. I may do it to when I
>> revive nd/pretty-placeholder-with-color-option.
>
> If I were designing --format today, I would certainly say so. The only
> thing holding me back would be backwards compatibility. We could get
> around that by introducing a new placeholder like %c(color) that behaves
> like %C(color), except respects the --color flag.

I think the %c(color) thing is a good way to go if we want to pursue
this.

Another possibility without wasting one more special letter would be
to allow %C(auto,red), perhaps like this (untested):

 pretty.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git i/pretty.c w/pretty.c
index dba6828..77cf826 100644
--- i/pretty.c
+++ w/pretty.c
@@ -960,12 +960,19 @@ static size_t format_commit_one(struct strbuf *sb, const char *placeholder,
 	switch (placeholder[0]) {
 	case 'C':
 		if (placeholder[1] == '(') {
-			const char *end = strchr(placeholder + 2, ')');
+			const char *begin = placeholder + 2;
+			const char *end = strchr(begin, ')');
 			char color[COLOR_MAXLEN];
+
 			if (!end)
 				return 0;
-			color_parse_mem(placeholder + 2,
-					end - (placeholder + 2),
+			if (!memcmp(begin, "auto,", 5)) {
+				if (!want_color(GIT_COLOR_AUTO))
+					return 0;
+				begin += 5;
+			}
+			color_parse_mem(begin,
+					end - begin,
 					"--pretty format", color);
 			strbuf_addstr(sb, color);
 			return end - placeholder + 1;