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[PATCH 2/2] log --format: teach %C(auto,black) to respect color config

From
Jeff King <peff@peff.net>
Date
Dec 17, 2012, 22:56 UTC
Message-ID
<20121217225649.GC1653@sigill.intra.peff.net>
In-Reply-To
<20121217225516.GA1408@sigill.intra.peff.net>
From: Junio C Hamano <gitster@pobox.com>

Traditionally, %C(color attr) always emitted the ANSI color sequence; it was up to the scripts that wanted to conditionally color their output to omit %C(...) specifier when they do not want colors.

Optionally allow "auto," to be prefixed to the color, so that the output is colored iff we would color regular "log" output (e.g., taking into account color.* and --color command line options).

Tests and pretty_context bits by Jeff King <peff@peff.net>.
Signed-off-by: Jeff King <peff@peff.net>
---
 Documentation/pretty-formats.txt |  6 ++++-
 commit.h                         |  1 +
 log-tree.c                       |  1 +
 pretty.c                         | 13 +++++++---
 t/t6006-rev-list-format.sh       | 55 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 72 insertions(+), 4 deletions(-)
diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index d9edded..105f18a 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -144,7 +144,11 @@ The placeholders are:
 - '%Cgreen': switch color to green
 - '%Cblue': switch color to blue
 - '%Creset': reset color
-- '%C(...)': color specification, as described in color.branch.* config option
+- '%C(...)': color specification, as described in color.branch.* config option;
+  adding `auto,` at the beginning will emit color only when colors are
+  enabled for log output (by `color.diff`, `color.ui`, or `--color`, and
+  respecting the `auto` settings of the former if we are going to a
+  terminal)
 - '%m': left, right or boundary mark
 - '%n': newline
 - '%%': a raw '%'
diff --git a/commit.h b/commit.h
index b6ad8f3..0f469e5 100644
--- a/commit.h
+++ b/commit.h
@@ -89,6 +89,7 @@ struct pretty_print_context {
 	char *notes_message;
 	struct reflog_walk_info *reflog_info;
 	const char *output_encoding;
+	int color;
 };
 
 struct userformat_want {
diff --git a/log-tree.c b/log-tree.c
index 4f86def..8876c73 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -671,6 +671,7 @@ void show_log(struct rev_info *opt)
 	ctx.preserve_subject = opt->preserve_subject;
 	ctx.reflog_info = opt->reflog_info;
 	ctx.fmt = opt->commit_format;
+	ctx.color = opt->diffopt.use_color;
 	pretty_print_commit(&ctx, commit, &msgbuf);
 
 	if (opt->add_signoff)
diff --git a/pretty.c b/pretty.c
index 5bdc2e7..e6a2886 100644
--- a/pretty.c
+++ b/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(c->pretty_ctx->color))
+					return end - placeholder + 1;
+				begin += 5;
+			}
+			color_parse_mem(begin,
+					end - begin,
 					"--pretty format", color);
 			strbuf_addstr(sb, color);
 			return end - placeholder + 1;
diff --git a/t/t6006-rev-list-format.sh b/t/t6006-rev-list-format.sh
index c0c62c9..3fc3b74 100755
--- a/t/t6006-rev-list-format.sh
+++ b/t/t6006-rev-list-format.sh
@@ -3,6 +3,7 @@ test_description='git rev-list --pretty=format test'
 test_description='git rev-list --pretty=format test'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-terminal.sh
 
 test_tick
 test_expect_success 'setup' '
@@ -19,6 +20,18 @@ test_format () {
 	"
 }
 
+# Feed to --format to provide predictable colored sequences.
+AUTO_COLOR='%C(auto,red)foo%C(auto,reset)'
+has_color () {
+	printf '\033[31mfoo\033[m\n' >expect &&
+	test_cmp expect "$1"
+}
+
+has_no_color () {
+	echo foo >expect &&
+	test_cmp expect "$1"
+}
+
 test_format percent %%h <<'EOF'
 commit 131a310eb913d107dd3c09a65d1651175898735d
 %h
@@ -124,6 +137,48 @@ EOF
 foo
 EOF
 
+test_expect_success '%C(auto) does not enable color by default' '
+	git log --format=$AUTO_COLOR -1 >actual &&
+	has_no_color actual
+'
+
+test_expect_success '%C(auto) enables colors for color.diff' '
+	git -c color.diff=always log --format=$AUTO_COLOR -1 >actual &&
+	has_color actual
+'
+
+test_expect_success '%C(auto) enables colors for color.ui' '
+	git -c color.ui=always log --format=$AUTO_COLOR -1 >actual &&
+	has_color actual
+'
+
+test_expect_success '%C(auto) respects --color' '
+	git log --format=$AUTO_COLOR -1 --color >actual &&
+	has_color actual
+'
+
+test_expect_success '%C(auto) respects --no-color' '
+	git -c color.ui=always log --format=$AUTO_COLOR -1 --no-color >actual &&
+	has_no_color actual
+'
+
+test_expect_success TTY '%C(auto) respects --color=auto (stdout is tty)' '
+	(
+		TERM=vt100 && export TERM &&
+		test_terminal \
+			git log --format=$AUTO_COLOR -1 --color=auto >actual &&
+		has_color actual
+	)
+'
+
+test_expect_success '%C(auto) respects --color=auto (stdout not tty)' '
+	(
+		TERM=vt100 && export TERM &&
+		git log --format=$AUTO_COLOR -1 --color=auto >actual &&
+		has_no_color actual
+	)
+'
+
 cat >commit-msg <<'EOF'
 Test printing of complex bodies
 
-- 
1.8.1.rc2.28.gce0611a
Previous: Jeff KingNext: Jeff King
Message 17 of 18 in “FW: Git log --graph doesn't output color when redirected”
  1. Srb, MichalDec 12, 2012
  2. Jeff KingDec 13, 2012
  3. Srb, MichalDec 13, 2012
  4. Nguyen Thai Ngoc DuyDec 15, 2012
  5. Jeff KingDec 15, 2012
  6. Junio C HamanoDec 15, 2012
  7. log --format: teach %C(auto,black) to paint it black only on terminalsJunio C Hamano, Dec 17, 2012
  8. Nguyen Thai Ngoc DuyDec 17, 2012
  9. Jeff KingDec 17, 2012
  10. Junio C HamanoDec 17, 2012
  11. Jeff KingDec 17, 2012
  12. Junio C HamanoDec 17, 2012
  13. Jeff KingDec 17, 2012
  14. 1/2 t6006: clean up whitespaceJunio C Hamano, Dec 17, 2012
  15. Jeff KingDec 17, 2012
  16. 1/2 t6006: clean up whitespaceJeff King, Dec 17, 2012
  17. 2/2 log --format: teach %C(auto,black) to respect color configJeff King, Dec 17, 2012
  18. Jeff KingDec 17, 2012

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