[PATCH 0/10] color and pager improvements

[PATCH 0/10] color and pager improvements

[Jeff King]

While looking at the pager and color code today, I decided to tackle two
long-standing bugs, which entailed a lot of refactoring of the color
code. The result fixes some minor bugs, and is a little nicer for
calling code to use.

  [01/10]: t7006: modernize calls to unset
  [02/10]: test-lib: add helper functions for config
  [03/10]: t7006: use test_config helpers

These three are just cleanup I noticed before adding new tests to t7006;
I hope that the helpers in 02/10 will be useful in a lot of other
places, though.

  [04/10]: setup_pager: set GIT_PAGER_IN_USE

This fixes Ingo's problem from:

  http://article.gmane.org/gmane.comp.version-control.git/179430

Namely that:

  git -p stash show

fails to use colors properly.

  [05/10]: diff: refactor COLOR_DIFF from a flag into an int
  [06/10]: git_config_colorbool: refactor stdout_is_tty handling
  [07/10]: color: delay auto-color decision until point of use

These three fix the problem Steffen mentioned here:

  http://article.gmane.org/gmane.comp.version-control.git/177792

Namely that pager.color doesn't work in many cases. This has been a
problem for years, but spread due to some pager-ordering changes late
last year (see the comments in 07/10). I actually wonder if anyone is
really using pager.color, as we haven't seen many complaints about it.

  [08/10]: config: refactor get_colorbool function
  [09/10]: diff: don't load color config in plumbing
  [10/10]: want_color: automatically fallback to color.ui

These three are refactoring that is made possible by 07/10. I think they
make the code cleaner, and hopefully the diffstat of 10/10 speaks for
itself.

-Peff

[PATCH 01/10] t7006: modernize calls to unset

[Jeff King]

These tests break &&-chaining to deal with broken "unset"
implementations. Instead, they should just use sane_unset.

Signed-off-by: Jeff King <peff@peff.net>
---
 t/t7006-pager.sh |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index ed7575d..c0a3135 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -402,7 +402,7 @@ test_core_pager_subdir    expect_success test_must_fail \
 					 'git -p apply </dev/null'
 
 test_expect_success TTY 'command-specific pager' '
-	unset PAGER GIT_PAGER;
+	sane_unset PAGER GIT_PAGER &&
 	echo "foo:initial" >expect &&
 	>actual &&
 	git config --unset core.pager &&
@@ -412,7 +412,7 @@ test_expect_success TTY 'command-specific pager' '
 '
 
 test_expect_success TTY 'command-specific pager overrides core.pager' '
-	unset PAGER GIT_PAGER;
+	sane_unset PAGER GIT_PAGER &&
 	echo "foo:initial" >expect &&
 	>actual &&
 	git config core.pager "exit 1"
-- 
1.7.6.10.g62f04

Re: [PATCH 01/10] t7006: modernize calls to unset

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

> These tests break &&-chaining to deal with broken "unset"
> implementations. Instead, they should just use sane_unset.

Thanks. I checked with POSIX again, wondering if I should tone the
"broken" down a bit, but it says:

  Unsetting a variable or function that was not previously set shall not
  be considered an error...

so they deserve "broken" label.

[PATCH 02/10] test-lib: add helper functions for config

[Jeff King]

There are a few common tasks when working with configuration
variables in tests; this patch aims to make them a little
easier to write and less error-prone.

When setting a variable, you should typically make sure to
clean it up after the test is finished, so as not to pollute
other tests. Like:

   test_when_finished 'git config --unset foo.bar' &&
   git config foo.bar baz

This patch lets you just write:

  test_config foo.bar baz

When clearing a variable that does not exist, git-config
will report a specific non-zero error code. Meaning that
tests which call "git config --unset" often either rely on
the prior tests having actually set it, or must use
test_might_fail. With this patch, the previous:

  test_might_fail git config --unset foo.bar

becomes:

  test_unconfig foo.bar

Not only is this easier to type, but it is more robust; it
will correctly detect errors from git-config besides "key
was not set".

Signed-off-by: Jeff King <peff@peff.net>
---
 t/test-lib.sh |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/t/test-lib.sh b/t/test-lib.sh
index df25f17..926667a 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -357,6 +357,24 @@ test_chmod () {
 	git update-index --add "--chmod=$@"
 }
 
+# Unset a configuration variable, but don't fail if it doesn't exist.
+test_unconfig () {
+	git config --unset-all "$@"
+	config_status=$?
+	case "$config_status" in
+	5) # ok, nothing to usnet
+		config_status=0
+		;;
+	esac
+	return $config_status
+}
+
+# Set git config, automatically unsetting it after the test is over.
+test_config () {
+	test_when_finished "test_unconfig '$1'" &&
+	git config "$@"
+}
+
 # Use test_set_prereq to tell that a particular prerequisite is available.
 # The prerequisite can later be checked for in two ways:
 #
-- 
1.7.6.10.g62f04

Re: [PATCH 02/10] test-lib: add helper functions for config

[Junio C Hamano]

Thanks.

> ...
> +# Unset a configuration variable, but don't fail if it doesn't exist.
> +test_unconfig () {
> +	git config --unset-all "$@"
> +	config_status=$?
> +	case "$config_status" in
> +	5) # ok, nothing to usnet
> +		config_status=0
> +		;;

Will queue with 's/nothing to usnet/nothing to unset/'.

[PATCH 03/10] t7006: use test_config helpers

[Jeff King]

In some cases, this is just making the test script a little
shorter and easier to read. However, there are several
places where we didn't take proper precautions against
polluting downstream tests with our config; this fixes them,
too.

Signed-off-by: Jeff King <peff@peff.net>
---
 t/t7006-pager.sh |   39 ++++++++++++++++++---------------------
 1 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index c0a3135..2ac729f 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -13,7 +13,7 @@ cleanup_fail() {
 
 test_expect_success 'setup' '
 	sane_unset GIT_PAGER GIT_PAGER_IN_USE &&
-	test_might_fail git config --unset core.pager &&
+	test_unconfig core.pager &&
 
 	PAGER="cat >paginated.out" &&
 	export PAGER &&
@@ -94,21 +94,19 @@ test_expect_success TTY 'no pager with --no-pager' '
 
 test_expect_success TTY 'configuration can disable pager' '
 	rm -f paginated.out &&
-	test_might_fail git config --unset pager.grep &&
+	test_unconfig pager.grep &&
 	test_terminal git grep initial &&
 	test -e paginated.out &&
 
 	rm -f paginated.out &&
-	git config pager.grep false &&
-	test_when_finished "git config --unset pager.grep" &&
+	test_config pager.grep false &&
 	test_terminal git grep initial &&
 	! test -e paginated.out
 '
 
 test_expect_success TTY 'git config uses a pager if configured to' '
 	rm -f paginated.out &&
-	git config pager.config true &&
-	test_when_finished "git config --unset pager.config" &&
+	test_config pager.config true &&
 	test_terminal git config --list &&
 	test -e paginated.out
 '
@@ -116,8 +114,7 @@ test_expect_success TTY 'git config uses a pager if configured to' '
 test_expect_success TTY 'configuration can enable pager (from subdir)' '
 	rm -f paginated.out &&
 	mkdir -p subdir &&
-	git config pager.bundle true &&
-	test_when_finished "git config --unset pager.bundle" &&
+	test_config pager.bundle true &&
 
 	git bundle create test.bundle --all &&
 	rm -f paginated.out subdir/paginated.out &&
@@ -150,7 +147,7 @@ test_expect_success 'tests can detect color' '
 
 test_expect_success 'no color when stdout is a regular file' '
 	rm -f colorless.log &&
-	git config color.ui auto ||
+	test_config color.ui auto ||
 	cleanup_fail &&
 
 	git log >colorless.log &&
@@ -159,7 +156,7 @@ test_expect_success 'no color when stdout is a regular file' '
 
 test_expect_success TTY 'color when writing to a pager' '
 	rm -f paginated.out &&
-	git config color.ui auto ||
+	test_config color.ui auto ||
 	cleanup_fail &&
 
 	(
@@ -172,7 +169,7 @@ test_expect_success TTY 'color when writing to a pager' '
 
 test_expect_success 'color when writing to a file intended for a pager' '
 	rm -f colorful.log &&
-	git config color.ui auto ||
+	test_config color.ui auto ||
 	cleanup_fail &&
 
 	(
@@ -221,7 +218,7 @@ test_default_pager() {
 
 	$test_expectation SIMPLEPAGER,TTY "$cmd - default pager is used by default" "
 		sane_unset PAGER GIT_PAGER &&
-		test_might_fail git config --unset core.pager &&
+		test_unconfig core.pager &&
 		rm -f default_pager_used ||
 		cleanup_fail &&
 
@@ -244,7 +241,7 @@ test_PAGER_overrides() {
 
 	$test_expectation TTY "$cmd - PAGER overrides default pager" "
 		sane_unset GIT_PAGER &&
-		test_might_fail git config --unset core.pager &&
+		test_unconfig core.pager &&
 		rm -f PAGER_used ||
 		cleanup_fail &&
 
@@ -277,7 +274,7 @@ test_core_pager() {
 
 		PAGER=wc &&
 		export PAGER &&
-		git config core.pager 'wc >core.pager_used' &&
+		test_config core.pager 'wc >core.pager_used' &&
 		$full_command &&
 		${if_local_config}test -e core.pager_used
 	"
@@ -307,7 +304,7 @@ test_pager_subdir_helper() {
 		PAGER=wc &&
 		stampname=\$(pwd)/core.pager_used &&
 		export PAGER stampname &&
-		git config core.pager 'wc >\"\$stampname\"' &&
+		test_config core.pager 'wc >\"\$stampname\"' &&
 		mkdir sub &&
 		(
 			cd sub &&
@@ -324,7 +321,7 @@ test_GIT_PAGER_overrides() {
 		rm -f GIT_PAGER_used ||
 		cleanup_fail &&
 
-		git config core.pager wc &&
+		test_config core.pager wc &&
 		GIT_PAGER='wc >GIT_PAGER_used' &&
 		export GIT_PAGER &&
 		$full_command &&
@@ -405,8 +402,8 @@ test_expect_success TTY 'command-specific pager' '
 	sane_unset PAGER GIT_PAGER &&
 	echo "foo:initial" >expect &&
 	>actual &&
-	git config --unset core.pager &&
-	git config pager.log "sed s/^/foo:/ >actual" &&
+	test_unconfig core.pager &&
+	test_config pager.log "sed s/^/foo:/ >actual" &&
 	test_terminal git log --format=%s -1 &&
 	test_cmp expect actual
 '
@@ -415,8 +412,8 @@ test_expect_success TTY 'command-specific pager overrides core.pager' '
 	sane_unset PAGER GIT_PAGER &&
 	echo "foo:initial" >expect &&
 	>actual &&
-	git config core.pager "exit 1"
-	git config pager.log "sed s/^/foo:/ >actual" &&
+	test_config core.pager "exit 1"
+	test_config pager.log "sed s/^/foo:/ >actual" &&
 	test_terminal git log --format=%s -1 &&
 	test_cmp expect actual
 '
@@ -425,7 +422,7 @@ test_expect_success TTY 'command-specific pager overridden by environment' '
 	GIT_PAGER="sed s/^/foo:/ >actual" && export GIT_PAGER &&
 	>actual &&
 	echo "foo:initial" >expect &&
-	git config pager.log "exit 1" &&
+	test_config pager.log "exit 1" &&
 	test_terminal git log --format=%s -1 &&
 	test_cmp expect actual
 '
-- 
1.7.6.10.g62f04

[PATCH 04/10] setup_pager: set GIT_PAGER_IN_USE

[Jeff King]

We have always set a global "spawned_pager" variable when we
start the pager. This lets us make the auto-color decision
later in the program as as "we are outputting to a terminal,
or to a pager which can handle colors".

Commit 6e9af86 added support for the GIT_PAGER_IN_USE
environment variable. An external program calling git (e.g.,
git-svn) could set this variable to indicate that it had
already started the pager, and that the decision about
auto-coloring should take that into account.

However, 6e9af86 failed to do the reverse, which is to tell
external programs when git itself has started the pager.
Thus a git command implemented as an external script that
has the pager turned on (e.g., "git -p stash show") would
not realize it was going to a pager, and would suppress
colors.

This patch remedies that; we always set GIT_PAGER_IN_USE
when we start the pager, and the value is respected by both
this program and any spawned children.

Signed-off-by: Jeff King <peff@peff.net>
---
 pager.c          |    8 +-------
 t/t7006-pager.sh |   11 +++++++++++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/pager.c b/pager.c
index dac358f..975955b 100644
--- a/pager.c
+++ b/pager.c
@@ -11,8 +11,6 @@
  * something different on Windows.
  */
 
-static int spawned_pager;
-
 #ifndef WIN32
 static void pager_preexec(void)
 {
@@ -78,7 +76,7 @@ void setup_pager(void)
 	if (!pager)
 		return;
 
-	spawned_pager = 1; /* means we are emitting to terminal */
+	setenv("GIT_PAGER_IN_USE", "true", 1);
 
 	/* spawn the pager */
 	pager_argv[0] = pager;
@@ -109,10 +107,6 @@ void setup_pager(void)
 int pager_in_use(void)
 {
 	const char *env;
-
-	if (spawned_pager)
-		return 1;
-
 	env = getenv("GIT_PAGER_IN_USE");
 	return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 }
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index 2ac729f..4884e1b 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -181,6 +181,17 @@ test_expect_success 'color when writing to a file intended for a pager' '
 	colorful colorful.log
 '
 
+test_expect_success TTY 'colors are sent to pager for external commands' '
+	test_config alias.externallog "!git log" &&
+	test_config color.ui auto &&
+	(
+		TERM=vt100 &&
+		export TERM &&
+		test_terminal git -p externallog
+	) &&
+	colorful paginated.out
+'
+
 # Use this helper to make it easy for the caller of your
 # terminal-using function to specify whether it should fail.
 # If you write
-- 
1.7.6.10.g62f04

[PATCH 05/10] diff: refactor COLOR_DIFF from a flag into an int

[Jeff King]

This lets us store more than just a bit flag for whether we
want color; we can also store whether we want automatic
colors. This can be useful for making the automatic-color
decision closer to the point of use.

This mostly just involves replacing DIFF_OPT_* calls with
manipulations of the flag. The biggest exception is that
calls to DIFF_OPT_TST must check for "o->use_color > 0",
which lets an "unknown" value (i.e., the default) stay at
"no color". In the previous code, a value of "-1" was not
propagated at all.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/merge.c |    2 --
 combine-diff.c  |    7 +++----
 diff.c          |   41 +++++++++++++++++++----------------------
 diff.h          |    5 +++--
 graph.c         |    2 +-
 log-tree.c      |    4 ++--
 wt-status.c     |    2 +-
 7 files changed, 29 insertions(+), 34 deletions(-)

diff --git a/builtin/merge.c b/builtin/merge.c
index 325891e..7209edf 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -390,8 +390,6 @@ static void finish(const unsigned char *new_head, const char *msg)
 		opts.output_format |=
 			DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 		opts.detect_rename = DIFF_DETECT_RENAME;
-		if (diff_use_color_default > 0)
-			DIFF_OPT_SET(&opts, COLOR_DIFF);
 		if (diff_setup_done(&opts) < 0)
 			die(_("diff_setup_done failed"));
 		diff_tree_sha1(head, new_head, "", &opts);
diff --git a/combine-diff.c b/combine-diff.c
index be67cfc..c588c79 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -702,9 +702,8 @@ static void show_combined_header(struct combine_diff_path *elem,
 	int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 	const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 	const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
-	int use_color = DIFF_OPT_TST(opt, COLOR_DIFF);
-	const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
-	const char *c_reset = diff_get_color(use_color, DIFF_RESET);
+	const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
+	const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
 	const char *abb;
 	int added = 0;
 	int deleted = 0;
@@ -964,7 +963,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 		show_combined_header(elem, num_parent, dense, rev,
 				     mode_differs, 1);
 		dump_sline(sline, cnt, num_parent,
-			   DIFF_OPT_TST(opt, COLOR_DIFF), result_deleted);
+			   opt->use_color, result_deleted);
 	}
 	free(result);
 
diff --git a/diff.c b/diff.c
index 93ef9a2..2d86abe 100644
--- a/diff.c
+++ b/diff.c
@@ -583,11 +583,10 @@ static void emit_rewrite_diff(const char *name_a,
 			      struct diff_options *o)
 {
 	int lc_a, lc_b;
-	int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 	const char *name_a_tab, *name_b_tab;
-	const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
-	const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
-	const char *reset = diff_get_color(color_diff, DIFF_RESET);
+	const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
+	const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
+	const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 	static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 	const char *a_prefix, *b_prefix;
 	char *data_one, *data_two;
@@ -623,7 +622,7 @@ static void emit_rewrite_diff(const char *name_a,
 	size_two = fill_textconv(textconv_two, two, &data_two);
 
 	memset(&ecbdata, 0, sizeof(ecbdata));
-	ecbdata.color_diff = color_diff;
+	ecbdata.color_diff = o->use_color > 0;
 	ecbdata.found_changesp = &o->found_changes;
 	ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 	ecbdata.opt = o;
@@ -1004,7 +1003,7 @@ static void free_diff_words_data(struct emit_callback *ecbdata)
 
 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 {
-	if (diff_use_color)
+	if (diff_use_color > 0)
 		return diff_colors[ix];
 	return "";
 }
@@ -1808,11 +1807,10 @@ static int is_conflict_marker(const char *line, int marker_size, unsigned long l
 static void checkdiff_consume(void *priv, char *line, unsigned long len)
 {
 	struct checkdiff_t *data = priv;
-	int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
 	int marker_size = data->conflict_marker_size;
-	const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
-	const char *reset = diff_get_color(color_diff, DIFF_RESET);
-	const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
+	const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
+	const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
+	const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
 	char *err;
 	char *line_prefix = "";
 	struct strbuf *msgbuf;
@@ -2157,7 +2155,7 @@ static void builtin_diff(const char *name_a,
 		memset(&xecfg, 0, sizeof(xecfg));
 		memset(&ecbdata, 0, sizeof(ecbdata));
 		ecbdata.label_path = lbl;
-		ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
+		ecbdata.color_diff = o->use_color > 0;
 		ecbdata.found_changesp = &o->found_changes;
 		ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 		if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
@@ -2205,7 +2203,7 @@ static void builtin_diff(const char *name_a,
 					break;
 				}
 			}
-			if (DIFF_OPT_TST(o, COLOR_DIFF)) {
+			if (o->use_color > 0) {
 				struct diff_words_style *st = ecbdata.diff_words->style;
 				st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
 				st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
@@ -2855,7 +2853,7 @@ static void run_diff_cmd(const char *pgm,
 		 */
 		fill_metainfo(msg, name, other, one, two, o, p,
 			      &must_show_header,
-			      DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
+			      o->use_color > 0 && !pgm);
 		xfrm_msg = msg->len ? msg->buf : NULL;
 	}
 
@@ -3021,8 +3019,7 @@ void diff_setup(struct diff_options *options)
 
 	options->change = diff_change;
 	options->add_remove = diff_addremove;
-	if (diff_use_color_default > 0)
-		DIFF_OPT_SET(options, COLOR_DIFF);
+	options->use_color = diff_use_color_default;
 	options->detect_rename = diff_detect_rename_default;
 
 	if (diff_no_prefix) {
@@ -3410,24 +3407,24 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--follow"))
 		DIFF_OPT_SET(options, FOLLOW_RENAMES);
 	else if (!strcmp(arg, "--color"))
-		DIFF_OPT_SET(options, COLOR_DIFF);
+		options->use_color = 1;
 	else if (!prefixcmp(arg, "--color=")) {
 		int value = git_config_colorbool(NULL, arg+8, -1);
 		if (value == 0)
-			DIFF_OPT_CLR(options, COLOR_DIFF);
+			options->use_color = 0;
 		else if (value > 0)
-			DIFF_OPT_SET(options, COLOR_DIFF);
+			options->use_color = 1;
 		else
 			return error("option `color' expects \"always\", \"auto\", or \"never\"");
 	}
 	else if (!strcmp(arg, "--no-color"))
-		DIFF_OPT_CLR(options, COLOR_DIFF);
+		options->use_color = 0;
 	else if (!strcmp(arg, "--color-words")) {
-		DIFF_OPT_SET(options, COLOR_DIFF);
+		options->use_color = 1;
 		options->word_diff = DIFF_WORDS_COLOR;
 	}
 	else if (!prefixcmp(arg, "--color-words=")) {
-		DIFF_OPT_SET(options, COLOR_DIFF);
+		options->use_color = 1;
 		options->word_diff = DIFF_WORDS_COLOR;
 		options->word_regex = arg + 14;
 	}
@@ -3440,7 +3437,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		if (!strcmp(type, "plain"))
 			options->word_diff = DIFF_WORDS_PLAIN;
 		else if (!strcmp(type, "color")) {
-			DIFF_OPT_SET(options, COLOR_DIFF);
+			options->use_color = 1;
 			options->word_diff = DIFF_WORDS_COLOR;
 		}
 		else if (!strcmp(type, "porcelain"))
diff --git a/diff.h b/diff.h
index b920a20..8c66b59 100644
--- a/diff.h
+++ b/diff.h
@@ -58,7 +58,7 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
 #define DIFF_OPT_SILENT_ON_REMOVE    (1 <<  5)
 #define DIFF_OPT_FIND_COPIES_HARDER  (1 <<  6)
 #define DIFF_OPT_FOLLOW_RENAMES      (1 <<  7)
-#define DIFF_OPT_COLOR_DIFF          (1 <<  8)
+/* (1 <<  8) unused */
 /* (1 <<  9) unused */
 #define DIFF_OPT_HAS_CHANGES         (1 << 10)
 #define DIFF_OPT_QUICK               (1 << 11)
@@ -101,6 +101,7 @@ struct diff_options {
 	const char *single_follow;
 	const char *a_prefix, *b_prefix;
 	unsigned flags;
+	int use_color;
 	int context;
 	int interhunkcontext;
 	int break_opt;
@@ -160,7 +161,7 @@ enum color_diff {
 };
 const char *diff_get_color(int diff_use_color, enum color_diff ix);
 #define diff_get_color_opt(o, ix) \
-	diff_get_color(DIFF_OPT_TST((o), COLOR_DIFF), ix)
+	diff_get_color((o)->use_color, ix)
 
 
 extern const char mime_boundary_leader[];
diff --git a/graph.c b/graph.c
index 2f6893d..556834a 100644
--- a/graph.c
+++ b/graph.c
@@ -347,7 +347,7 @@ static struct commit_list *first_interesting_parent(struct git_graph *graph)
 
 static unsigned short graph_get_current_column_color(const struct git_graph *graph)
 {
-	if (!DIFF_OPT_TST(&graph->revs->diffopt, COLOR_DIFF))
+	if (graph->revs->diffopt.use_color <= 0)
 		return column_colors_max;
 	return graph->default_column_color;
 }
diff --git a/log-tree.c b/log-tree.c
index e945701..9ba8fb2 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -31,7 +31,7 @@ static char decoration_colors[][COLOR_MAXLEN] = {
 
 static const char *decorate_get_color(int decorate_use_color, enum decoration_type ix)
 {
-	if (decorate_use_color)
+	if (decorate_use_color > 0)
 		return decoration_colors[ix];
 	return "";
 }
@@ -77,7 +77,7 @@ int parse_decorate_color_config(const char *var, const int ofs, const char *valu
  * for showing the commit sha1, use the same check for --decorate
  */
 #define decorate_get_color_opt(o, ix) \
-	decorate_get_color(DIFF_OPT_TST((o), COLOR_DIFF), ix)
+	decorate_get_color((o)->use_color, ix)
 
 static void add_name_decoration(enum decoration_type type, const char *name, struct object *obj)
 {
diff --git a/wt-status.c b/wt-status.c
index 0237772..ee03431 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -681,7 +681,7 @@ static void wt_status_print_verbose(struct wt_status *s)
 	 * will have checked isatty on stdout).
 	 */
 	if (s->fp != stdout)
-		DIFF_OPT_CLR(&rev.diffopt, COLOR_DIFF);
+		rev.diffopt.use_color = 0;
 	run_diff_index(&rev, 1);
 }
 
-- 
1.7.6.10.g62f04

[PATCH 06/10] git_config_colorbool: refactor stdout_is_tty handling

[Jeff King]

Usually this function figures out for itself whether stdout
is a tty. However, it has an extra parameter just to allow
git-config to override the auto-detection for its
--get-colorbool option.

Instead of an extra parameter, let's just use a global
variable. This makes calling easier in the common case, and
will make refactoring the colorbool code much simpler.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/branch.c      |    2 +-
 builtin/commit.c      |    2 +-
 builtin/config.c      |   23 +++++++----------------
 builtin/grep.c        |    2 +-
 builtin/show-branch.c |    2 +-
 color.c               |   11 ++++++-----
 color.h               |    8 +++++++-
 diff.c                |    4 ++--
 parse-options.c       |    2 +-
 9 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/builtin/branch.c b/builtin/branch.c
index 3142daa..b15fee5 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -71,7 +71,7 @@ static int parse_branch_color_slot(const char *var, int ofs)
 static int git_branch_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "color.branch")) {
-		branch_use_color = git_config_colorbool(var, value, -1);
+		branch_use_color = git_config_colorbool(var, value);
 		return 0;
 	}
 	if (!prefixcmp(var, "color.branch.")) {
diff --git a/builtin/commit.c b/builtin/commit.c
index e1af9b1..295803a 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1144,7 +1144,7 @@ static int git_status_config(const char *k, const char *v, void *cb)
 		return 0;
 	}
 	if (!strcmp(k, "status.color") || !strcmp(k, "color.status")) {
-		s->use_color = git_config_colorbool(k, v, -1);
+		s->use_color = git_config_colorbool(k, v);
 		return 0;
 	}
 	if (!prefixcmp(k, "status.color.") || !prefixcmp(k, "color.status.")) {
diff --git a/builtin/config.c b/builtin/config.c
index 211e118..5505ced 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -303,24 +303,17 @@ static void get_color(const char *def_color)
 	fputs(parsed_color, stdout);
 }
 
-static int stdout_is_tty;
 static int get_colorbool_found;
 static int get_diff_color_found;
 static int git_get_colorbool_config(const char *var, const char *value,
 		void *cb)
 {
-	if (!strcmp(var, get_colorbool_slot)) {
-		get_colorbool_found =
-			git_config_colorbool(var, value, stdout_is_tty);
-	}
-	if (!strcmp(var, "diff.color")) {
-		get_diff_color_found =
-			git_config_colorbool(var, value, stdout_is_tty);
-	}
-	if (!strcmp(var, "color.ui")) {
-		git_use_color_default = git_config_colorbool(var, value, stdout_is_tty);
-		return 0;
-	}
+	if (!strcmp(var, get_colorbool_slot))
+		get_colorbool_found = git_config_colorbool(var, value);
+	else if (!strcmp(var, "diff.color"))
+		get_diff_color_found = git_config_colorbool(var, value);
+	else if (!strcmp(var, "color.ui"))
+		git_use_color_default = git_config_colorbool(var, value);
 	return 0;
 }
 
@@ -510,9 +503,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 	else if (actions == ACTION_GET_COLORBOOL) {
 		if (argc == 1)
-			stdout_is_tty = git_config_bool("command line", argv[0]);
-		else if (argc == 0)
-			stdout_is_tty = isatty(1);
+			color_stdout_is_tty = git_config_bool("command line", argv[0]);
 		return get_colorbool(argc != 0);
 	}
 
diff --git a/builtin/grep.c b/builtin/grep.c
index cccf8da..d80db22 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -325,7 +325,7 @@ static int grep_config(const char *var, const char *value, void *cb)
 	}
 
 	if (!strcmp(var, "color.grep"))
-		opt->color = git_config_colorbool(var, value, -1);
+		opt->color = git_config_colorbool(var, value);
 	else if (!strcmp(var, "color.grep.context"))
 		color = opt->color_context;
 	else if (!strcmp(var, "color.grep.filename"))
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index facc63a..e6650b4 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -573,7 +573,7 @@ static int git_show_branch_config(const char *var, const char *value, void *cb)
 	}
 
 	if (!strcmp(var, "color.showbranch")) {
-		showbranch_use_color = git_config_colorbool(var, value, -1);
+		showbranch_use_color = git_config_colorbool(var, value);
 		return 0;
 	}
 
diff --git a/color.c b/color.c
index 3db214c..67affa4 100644
--- a/color.c
+++ b/color.c
@@ -2,6 +2,7 @@
 #include "color.h"
 
 int git_use_color_default = 0;
+int color_stdout_is_tty = -1;
 
 /*
  * The list of available column colors.
@@ -157,7 +158,7 @@ bad:
 	die("bad color value '%.*s' for variable '%s'", value_len, value, var);
 }
 
-int git_config_colorbool(const char *var, const char *value, int stdout_is_tty)
+int git_config_colorbool(const char *var, const char *value)
 {
 	if (value) {
 		if (!strcasecmp(value, "never"))
@@ -177,9 +178,9 @@ int git_config_colorbool(const char *var, const char *value, int stdout_is_tty)
 
 	/* any normal truth value defaults to 'auto' */
  auto_color:
-	if (stdout_is_tty < 0)
-		stdout_is_tty = isatty(1);
-	if (stdout_is_tty || (pager_in_use() && pager_use_color)) {
+	if (color_stdout_is_tty < 0)
+		color_stdout_is_tty = isatty(1);
+	if (color_stdout_is_tty || (pager_in_use() && pager_use_color)) {
 		char *term = getenv("TERM");
 		if (term && strcmp(term, "dumb"))
 			return 1;
@@ -190,7 +191,7 @@ int git_config_colorbool(const char *var, const char *value, int stdout_is_tty)
 int git_color_default_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "color.ui")) {
-		git_use_color_default = git_config_colorbool(var, value, -1);
+		git_use_color_default = git_config_colorbool(var, value);
 		return 0;
 	}
 
diff --git a/color.h b/color.h
index 68a926a..a190a25 100644
--- a/color.h
+++ b/color.h
@@ -58,11 +58,17 @@ extern const char *column_colors_ansi[];
 extern const int column_colors_ansi_max;
 
 /*
+ * Generally the color code will lazily figure this out itself, but
+ * this provides a mechanism for callers to override autodetection.
+ */
+extern int color_stdout_is_tty;
+
+/*
  * Use this instead of git_default_config if you need the value of color.ui.
  */
 int git_color_default_config(const char *var, const char *value, void *cb);
 
-int git_config_colorbool(const char *var, const char *value, int stdout_is_tty);
+int git_config_colorbool(const char *var, const char *value);
 void color_parse(const char *value, const char *var, char *dst);
 void color_parse_mem(const char *value, int len, const char *var, char *dst);
 __attribute__((format (printf, 3, 4)))
diff --git a/diff.c b/diff.c
index 2d86abe..2dfc359 100644
--- a/diff.c
+++ b/diff.c
@@ -137,7 +137,7 @@ static int git_config_rename(const char *var, const char *value)
 int git_diff_ui_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
-		diff_use_color_default = git_config_colorbool(var, value, -1);
+		diff_use_color_default = git_config_colorbool(var, value);
 		return 0;
 	}
 	if (!strcmp(var, "diff.renames")) {
@@ -3409,7 +3409,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 	else if (!strcmp(arg, "--color"))
 		options->use_color = 1;
 	else if (!prefixcmp(arg, "--color=")) {
-		int value = git_config_colorbool(NULL, arg+8, -1);
+		int value = git_config_colorbool(NULL, arg+8);
 		if (value == 0)
 			options->use_color = 0;
 		else if (value > 0)
diff --git a/parse-options.c b/parse-options.c
index 879ea82..be4383e 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -621,7 +621,7 @@ int parse_opt_color_flag_cb(const struct option *opt, const char *arg,
 
 	if (!arg)
 		arg = unset ? "never" : (const char *)opt->defval;
-	value = git_config_colorbool(NULL, arg, -1);
+	value = git_config_colorbool(NULL, arg);
 	if (value < 0)
 		return opterror(opt,
 			"expects \"always\", \"auto\", or \"never\"", 0);
-- 
1.7.6.10.g62f04

[PATCH 07/10] color: delay auto-color decision until point of use

[Jeff King]

When we read a color value either from a config file or from
the command line, we use git_config_colorbool to convert it
from the tristate always/never/auto into a single yes/no
boolean value.

This has some timing implications with respect to starting
a pager.

If we start (or decide not to start) the pager before
checking the colorbool, everything is fine. Either isatty(1)
will give us the right information, or we will properly
check for pager_in_use().

However, if we decide to start a pager after we have checked
the colorbool, things are not so simple. If stdout is a tty,
then we will have already decided to use color. However, the
user may also have configured color.pager not to use color
with the pager. In this case, we need to actually turn off
color. Unfortunately, the pager code has no idea which color
variables were turned on (and there are many of them
throughout the code, and they may even have been manipulated
after the colorbool selection by something like "--color" on
the command line).

This bug can be seen any time a pager is started after
config and command line options are checked. This has
affected "git diff" since 89d07f7 (diff: don't run pager if
user asked for a diff style exit code, 2007-08-12). It has
also affect the log family since 1fda91b (Fix 'git log'
early pager startup error case, 2010-08-24).

This patch splits the notion of parsing a colorbool and
actually checking the configuration. The "use_color"
variables now have an additional possible value,
GIT_COLOR_AUTO. Users of the variable should use the new
"want_color()" wrapper, which will lazily determine and
cache the auto-color decision.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/branch.c      |    2 +-
 builtin/config.c      |    2 ++
 builtin/show-branch.c |    4 ++--
 color.c               |   20 ++++++++++++++++++--
 color.h               |   11 +++++++++++
 diff.c                |   17 +++++++----------
 graph.c               |    2 +-
 grep.c                |    2 +-
 log-tree.c            |    2 +-
 t/t7006-pager.sh      |   12 ++++++++++++
 wt-status.c           |    4 +++-
 11 files changed, 59 insertions(+), 19 deletions(-)

diff --git a/builtin/branch.c b/builtin/branch.c
index b15fee5..d6d3c7d 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -88,7 +88,7 @@ static int git_branch_config(const char *var, const char *value, void *cb)
 
 static const char *branch_get_color(enum color_branch ix)
 {
-	if (branch_use_color > 0)
+	if (want_color(branch_use_color))
 		return branch_colors[ix];
 	return "";
 }
diff --git a/builtin/config.c b/builtin/config.c
index 5505ced..3a09296 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -330,6 +330,8 @@ static int get_colorbool(int print)
 			get_colorbool_found = git_use_color_default;
 	}
 
+	get_colorbool_found = want_color(get_colorbool_found);
+
 	if (print) {
 		printf("%s\n", get_colorbool_found ? "true" : "false");
 		return 0;
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index e6650b4..4b726fa 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -26,14 +26,14 @@ static const char **default_arg;
 
 static const char *get_color_code(int idx)
 {
-	if (showbranch_use_color)
+	if (want_color(showbranch_use_color))
 		return column_colors_ansi[idx % column_colors_ansi_max];
 	return "";
 }
 
 static const char *get_color_reset_code(void)
 {
-	if (showbranch_use_color)
+	if (want_color(showbranch_use_color))
 		return GIT_COLOR_RESET;
 	return "";
 }
diff --git a/color.c b/color.c
index 67affa4..8586417 100644
--- a/color.c
+++ b/color.c
@@ -166,7 +166,7 @@ int git_config_colorbool(const char *var, const char *value)
 		if (!strcasecmp(value, "always"))
 			return 1;
 		if (!strcasecmp(value, "auto"))
-			goto auto_color;
+			return GIT_COLOR_AUTO;
 	}
 
 	if (!var)
@@ -177,7 +177,11 @@ int git_config_colorbool(const char *var, const char *value)
 		return 0;
 
 	/* any normal truth value defaults to 'auto' */
- auto_color:
+	return GIT_COLOR_AUTO;
+}
+
+static int check_auto_color(void)
+{
 	if (color_stdout_is_tty < 0)
 		color_stdout_is_tty = isatty(1);
 	if (color_stdout_is_tty || (pager_in_use() && pager_use_color)) {
@@ -188,6 +192,18 @@ int git_config_colorbool(const char *var, const char *value)
 	return 0;
 }
 
+int want_color(int var)
+{
+	static int want_auto = -1;
+
+	if (var == GIT_COLOR_AUTO) {
+		if (want_auto < 0)
+			want_auto = check_auto_color();
+		return want_auto;
+	}
+	return var > 0;
+}
+
 int git_color_default_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "color.ui")) {
diff --git a/color.h b/color.h
index a190a25..d715fd5 100644
--- a/color.h
+++ b/color.h
@@ -49,6 +49,16 @@ struct strbuf;
 #define GIT_COLOR_NIL "NIL"
 
 /*
+ * The first three are chosen to match common usage in the code, and what is
+ * returned from git_config_colorbool. The "auto" value can be returned from
+ * config_colorbool, and will be converted by want_color() into either 0 or 1.
+ */
+#define GIT_COLOR_UNKNOWN -1
+#define GIT_COLOR_ALWAYS 0
+#define GIT_COLOR_NEVER  1
+#define GIT_COLOR_AUTO   2
+
+/*
  * This variable stores the value of color.ui
  */
 extern int git_use_color_default;
@@ -69,6 +79,7 @@ extern int color_stdout_is_tty;
 int git_color_default_config(const char *var, const char *value, void *cb);
 
 int git_config_colorbool(const char *var, const char *value);
+int want_color(int var);
 void color_parse(const char *value, const char *var, char *dst);
 void color_parse_mem(const char *value, int len, const char *var, char *dst);
 __attribute__((format (printf, 3, 4)))
diff --git a/diff.c b/diff.c
index 2dfc359..29cecf1 100644
--- a/diff.c
+++ b/diff.c
@@ -622,7 +622,7 @@ static void emit_rewrite_diff(const char *name_a,
 	size_two = fill_textconv(textconv_two, two, &data_two);
 
 	memset(&ecbdata, 0, sizeof(ecbdata));
-	ecbdata.color_diff = o->use_color > 0;
+	ecbdata.color_diff = want_color(o->use_color);
 	ecbdata.found_changesp = &o->found_changes;
 	ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 	ecbdata.opt = o;
@@ -1003,7 +1003,7 @@ static void free_diff_words_data(struct emit_callback *ecbdata)
 
 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 {
-	if (diff_use_color > 0)
+	if (want_color(diff_use_color))
 		return diff_colors[ix];
 	return "";
 }
@@ -2155,7 +2155,7 @@ static void builtin_diff(const char *name_a,
 		memset(&xecfg, 0, sizeof(xecfg));
 		memset(&ecbdata, 0, sizeof(ecbdata));
 		ecbdata.label_path = lbl;
-		ecbdata.color_diff = o->use_color > 0;
+		ecbdata.color_diff = want_color(o->use_color);
 		ecbdata.found_changesp = &o->found_changes;
 		ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 		if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
@@ -2203,7 +2203,7 @@ static void builtin_diff(const char *name_a,
 					break;
 				}
 			}
-			if (o->use_color > 0) {
+			if (want_color(o->use_color)) {
 				struct diff_words_style *st = ecbdata.diff_words->style;
 				st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
 				st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
@@ -2853,7 +2853,7 @@ static void run_diff_cmd(const char *pgm,
 		 */
 		fill_metainfo(msg, name, other, one, two, o, p,
 			      &must_show_header,
-			      o->use_color > 0 && !pgm);
+			      want_color(o->use_color) && !pgm);
 		xfrm_msg = msg->len ? msg->buf : NULL;
 	}
 
@@ -3410,12 +3410,9 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->use_color = 1;
 	else if (!prefixcmp(arg, "--color=")) {
 		int value = git_config_colorbool(NULL, arg+8);
-		if (value == 0)
-			options->use_color = 0;
-		else if (value > 0)
-			options->use_color = 1;
-		else
+		if (value < 0)
 			return error("option `color' expects \"always\", \"auto\", or \"never\"");
+		options->use_color = value;
 	}
 	else if (!strcmp(arg, "--no-color"))
 		options->use_color = 0;
diff --git a/graph.c b/graph.c
index 556834a..7358416 100644
--- a/graph.c
+++ b/graph.c
@@ -347,7 +347,7 @@ static struct commit_list *first_interesting_parent(struct git_graph *graph)
 
 static unsigned short graph_get_current_column_color(const struct git_graph *graph)
 {
-	if (graph->revs->diffopt.use_color <= 0)
+	if (!want_color(graph->revs->diffopt.use_color))
 		return column_colors_max;
 	return graph->default_column_color;
 }
diff --git a/grep.c b/grep.c
index 04e9ba4..abf4288 100644
--- a/grep.c
+++ b/grep.c
@@ -430,7 +430,7 @@ static int word_char(char ch)
 static void output_color(struct grep_opt *opt, const void *data, size_t size,
 			 const char *color)
 {
-	if (opt->color && color && color[0]) {
+	if (want_color(opt->color) && color && color[0]) {
 		opt->output(opt, color, strlen(color));
 		opt->output(opt, data, size);
 		opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
diff --git a/log-tree.c b/log-tree.c
index 9ba8fb2..95d6d40 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -31,7 +31,7 @@ static char decoration_colors[][COLOR_MAXLEN] = {
 
 static const char *decorate_get_color(int decorate_use_color, enum decoration_type ix)
 {
-	if (decorate_use_color > 0)
+	if (want_color(decorate_use_color))
 		return decoration_colors[ix];
 	return "";
 }
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index 4884e1b..4582336 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -167,6 +167,18 @@ test_expect_success TTY 'color when writing to a pager' '
 	colorful paginated.out
 '
 
+test_expect_success TTY 'colors are suppressed by color.pager' '
+	rm -f paginated.out &&
+	test_config color.ui auto &&
+	test_config color.pager false &&
+	(
+		TERM=vt100 &&
+		export TERM &&
+		test_terminal git log
+	) &&
+	! colorful paginated.out
+'
+
 test_expect_success 'color when writing to a file intended for a pager' '
 	rm -f colorful.log &&
 	test_config color.ui auto ||
diff --git a/wt-status.c b/wt-status.c
index ee03431..8836a52 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -26,7 +26,9 @@ static char default_wt_status_colors[][COLOR_MAXLEN] = {
 
 static const char *color(int slot, struct wt_status *s)
 {
-	const char *c = s->use_color > 0 ? s->color_palette[slot] : "";
+	const char *c = "";
+	if (want_color(s->use_color))
+		c = s->color_palette[slot];
 	if (slot == WT_STATUS_ONBRANCH && color_is_nil(c))
 		c = s->color_palette[WT_STATUS_HEADER];
 	return c;
-- 
1.7.6.10.g62f04

Re: [PATCH 07/10] color: delay auto-color decision until point of use

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

> diff --git a/color.h b/color.h
> index a190a25..d715fd5 100644
> --- a/color.h
> +++ b/color.h
> @@ -49,6 +49,16 @@ struct strbuf;
>  #define GIT_COLOR_NIL "NIL"
>  
>  /*
> + * The first three are chosen to match common usage in the code, and what is
> + * returned from git_config_colorbool. The "auto" value can be returned from
> + * config_colorbool, and will be converted by want_color() into either 0 or 1.
> + */
> +#define GIT_COLOR_UNKNOWN -1
> +#define GIT_COLOR_ALWAYS 0
> +#define GIT_COLOR_NEVER  1
> +#define GIT_COLOR_AUTO   2

The ALWAYS/NEVER somehow go against my intuition. Let me trace one
codepath starting from git_branch_config().

    branch_use_color is set from git_config_colorbool("color.branch");
    -> given "never", git_config_colorbool() returns 0;
    branch_get_color() asks want_color(branch_use_color);
    -> want_color() returns if the given value is positive.

Because git_config_colorbool() does not use the above symbolic constants,
everything goes well, but aren't these two swapped?

Re: [PATCH 07/10] color: delay auto-color decision until point of use

[Jeff King]

On Thu, Aug 18, 2011 at 02:59:37PM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > diff --git a/color.h b/color.h
> > index a190a25..d715fd5 100644
> > --- a/color.h
> > +++ b/color.h
> > @@ -49,6 +49,16 @@ struct strbuf;
> >  #define GIT_COLOR_NIL "NIL"
> >  
> >  /*
> > + * The first three are chosen to match common usage in the code, and what is
> > + * returned from git_config_colorbool. The "auto" value can be returned from
> > + * config_colorbool, and will be converted by want_color() into either 0 or 1.
> > + */
> > +#define GIT_COLOR_UNKNOWN -1
> > +#define GIT_COLOR_ALWAYS 0
> > +#define GIT_COLOR_NEVER  1
> > +#define GIT_COLOR_AUTO   2
> 
> The ALWAYS/NEVER somehow go against my intuition. Let me trace one
> codepath starting from git_branch_config().
> 
>     branch_use_color is set from git_config_colorbool("color.branch");
>     -> given "never", git_config_colorbool() returns 0;
>     branch_get_color() asks want_color(branch_use_color);
>     -> want_color() returns if the given value is positive.
> 
> Because git_config_colorbool() does not use the above symbolic constants,
> everything goes well, but aren't these two swapped?

Oooops. Yes, they are completely swapped and I'm an idiot. But as you
noticed, we don't actually _use_ them anywhere. I started on replacing
every "0" with NEVER, every "1" with ALWAYS, and every "-1" with
UNKNOWN. But it really bloated the patch, and didn't actually make the
code any more readable.

The only symbolic constant that is really necessary is the AUTO one. I
just felt odd randomly defining "2" as GIT_COLOR_AUTO, but not defining
the other possible values of the enumeration. So definitely they should
be swapped. I'm also fine with just dropping all of them except AUTO.

-Peff

[PATCH 08/10] config: refactor get_colorbool function

[Jeff King]

For "git config --get-colorbool color.foo", we use a custom
callback that looks not only for the key that the user gave
us, but also for "diff.color" (for backwards compatibility)
and "color.ui" (as a fallback).

For the former, we use a custom variable to store the
diff.color value. For the latter, though, we store it in the
main "git_use_color_default" variable, turning on color.ui
for any other parts of git that respect this value.

In practice, this doesn't cause any bugs, because git-config
runs without caring about git_use_color_default, and then
exits. But it crosses module boundaries in an unusual and
confusing way, and it makes refactoring color handling
harder than it needs to be.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/config.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/builtin/config.c b/builtin/config.c
index 3a09296..0b4ecac 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -305,6 +305,7 @@ static void get_color(const char *def_color)
 
 static int get_colorbool_found;
 static int get_diff_color_found;
+static int get_color_ui_found;
 static int git_get_colorbool_config(const char *var, const char *value,
 		void *cb)
 {
@@ -313,7 +314,7 @@ static int git_get_colorbool_config(const char *var, const char *value,
 	else if (!strcmp(var, "diff.color"))
 		get_diff_color_found = git_config_colorbool(var, value);
 	else if (!strcmp(var, "color.ui"))
-		git_use_color_default = git_config_colorbool(var, value);
+		get_color_ui_found = git_config_colorbool(var, value);
 	return 0;
 }
 
@@ -327,7 +328,7 @@ static int get_colorbool(int print)
 		if (!strcmp(get_colorbool_slot, "color.diff"))
 			get_colorbool_found = get_diff_color_found;
 		if (get_colorbool_found < 0)
-			get_colorbool_found = git_use_color_default;
+			get_colorbool_found = get_color_ui_found;
 	}
 
 	get_colorbool_found = want_color(get_colorbool_found);
-- 
1.7.6.10.g62f04

[PATCH 09/10] diff: don't load color config in plumbing

[Jeff King]

The diff config callback is split into two functions: one
which loads "ui" config, and one which loads "basic" config.
The former chains to the latter, as the diff UI config is a
superset of the plumbing config.

The color.diff variable is only loaded in the UI config.
However, the basic config actually chains to
git_color_default_config, which loads color.ui. This doesn't
actually cause any bugs, because the plumbing diff code does
not actually look at the value of color.ui.

However, it is somewhat nonsensical, and it makes it
difficult to refactor the color code. It probably came about
because there is no git_color_config to load only color
config, but rather just git_color_default_config, which
loads color config and chains to git_default_config.

This patch splits out the color-specific portion of
git_color_default_config so that the diff UI config can call
it directly. This is perhaps better explained by the
chaining of callbacks. Before we had:

  git_diff_ui_config
    -> git_diff_basic_config
      -> git_color_default_config
        -> git_default_config

Now we have:

  git_diff_ui_config
    -> git_color_config
    -> git_diff_basic_config
      -> git_default_config

Signed-off-by: Jeff King <peff@peff.net>
---
 color.c |   10 +++++++++-
 color.h |    4 +++-
 diff.c  |    5 ++++-
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/color.c b/color.c
index 8586417..ec96fe1 100644
--- a/color.c
+++ b/color.c
@@ -204,13 +204,21 @@ int want_color(int var)
 	return var > 0;
 }
 
-int git_color_default_config(const char *var, const char *value, void *cb)
+int git_color_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "color.ui")) {
 		git_use_color_default = git_config_colorbool(var, value);
 		return 0;
 	}
 
+	return 0;
+}
+
+int git_color_default_config(const char *var, const char *value, void *cb)
+{
+	if (git_color_config(var, value, cb) < 0)
+		return -1;
+
 	return git_default_config(var, value, cb);
 }
 
diff --git a/color.h b/color.h
index d715fd5..5949bcd 100644
--- a/color.h
+++ b/color.h
@@ -74,8 +74,10 @@ extern const int column_colors_ansi_max;
 extern int color_stdout_is_tty;
 
 /*
- * Use this instead of git_default_config if you need the value of color.ui.
+ * Use the first one if you need only color config; the second is a convenience
+ * if you are just going to change to git_default_config, too.
  */
+int git_color_config(const char *var, const char *value, void *cb);
 int git_color_default_config(const char *var, const char *value, void *cb);
 
 int git_config_colorbool(const char *var, const char *value);
diff --git a/diff.c b/diff.c
index 29cecf1..0a22320 100644
--- a/diff.c
+++ b/diff.c
@@ -164,6 +164,9 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 	if (!strcmp(var, "diff.ignoresubmodules"))
 		handle_ignore_submodules_arg(&default_diff_options, value);
 
+	if (git_color_config(var, value, cb) < 0)
+		return -1;
+
 	return git_diff_basic_config(var, value, cb);
 }
 
@@ -212,7 +215,7 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
 	if (!prefixcmp(var, "submodule."))
 		return parse_submodule_config_option(var, value);
 
-	return git_color_default_config(var, value, cb);
+	return git_default_config(var, value, cb);
 }
 
 static char *quote_two(const char *one, const char *two)
-- 
1.7.6.10.g62f04

[PATCH 10/10] want_color: automatically fallback to color.ui

[Jeff King]

All of the "do we want color" flags default to -1 to
indicate that we don't have any color configured. This value
is handled in one of two ways:

  1. In porcelain, we check early on whether the value is
     still -1 after reading the config, and set it to the
     value of color.ui (which defaults to 0).

  2. In plumbing, it stays untouched as -1, and want_color
     defaults it to off.

This works fine, but means that every porcelain has to check
and reassign its color flag. Now that want_color gives us a
place to put this check in a single spot, we can do that,
simplifying the calling code.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/branch.c      |    3 ---
 builtin/commit.c      |   11 +----------
 builtin/diff.c        |    3 ---
 builtin/grep.c        |    2 --
 builtin/log.c         |   12 ------------
 builtin/merge.c       |    4 ----
 builtin/show-branch.c |    3 ---
 color.c               |    7 +++++--
 color.h               |    5 -----
 9 files changed, 6 insertions(+), 44 deletions(-)

diff --git a/builtin/branch.c b/builtin/branch.c
index d6d3c7d..73d4170 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -673,9 +673,6 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 
 	git_config(git_branch_config, NULL);
 
-	if (branch_use_color == -1)
-		branch_use_color = git_use_color_default;
-
 	track = git_branch_track;
 
 	head = resolve_ref("HEAD", head_sha1, 0, NULL);
diff --git a/builtin/commit.c b/builtin/commit.c
index 295803a..9763146 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1237,10 +1237,6 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 
 	if (s.relative_paths)
 		s.prefix = prefix;
-	if (s.use_color == -1)
-		s.use_color = git_use_color_default;
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
 
 	switch (status_format) {
 	case STATUS_FORMAT_SHORT:
@@ -1394,15 +1390,10 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	git_config(git_commit_config, &s);
 	determine_whence(&s);
 
-	if (s.use_color == -1)
-		s.use_color = git_use_color_default;
 	argc = parse_and_validate_options(argc, argv, builtin_commit_usage,
 					  prefix, &s);
-	if (dry_run) {
-		if (diff_use_color_default == -1)
-			diff_use_color_default = git_use_color_default;
+	if (dry_run)
 		return dry_run_commit(argc, argv, prefix, &s);
-	}
 	index_file = prepare_index(argc, argv, prefix, 0);
 
 	/* Set up everything for writing the commit object.  This includes
diff --git a/builtin/diff.c b/builtin/diff.c
index 69cd5ee..1118689 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -277,9 +277,6 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 	gitmodules_config();
 	git_config(git_diff_ui_config, NULL);
 
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
-
 	init_revisions(&rev, prefix);
 
 	/* If this is a no-index diff, just run it and exit there. */
diff --git a/builtin/grep.c b/builtin/grep.c
index d80db22..2cbf01f 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -896,8 +896,6 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	strcpy(opt.color_sep, GIT_COLOR_CYAN);
 	opt.color = -1;
 	git_config(grep_config, &opt);
-	if (opt.color == -1)
-		opt.color = git_use_color_default;
 
 	/*
 	 * If there is no -- then the paths must exist in the working
diff --git a/builtin/log.c b/builtin/log.c
index 5c2af59..d760ee0 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -359,9 +359,6 @@ int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 
 	git_config(git_log_config, NULL);
 
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
-
 	init_revisions(&rev, prefix);
 	rev.diff = 1;
 	rev.simplify_history = 0;
@@ -446,9 +443,6 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 
 	git_config(git_log_config, NULL);
 
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
-
 	init_pathspec(&match_all, NULL);
 	init_revisions(&rev, prefix);
 	rev.diff = 1;
@@ -524,9 +518,6 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 
 	git_config(git_log_config, NULL);
 
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
-
 	init_revisions(&rev, prefix);
 	init_reflog_walk(&rev.reflog_info);
 	rev.verbose_header = 1;
@@ -549,9 +540,6 @@ int cmd_log(int argc, const char **argv, const char *prefix)
 
 	git_config(git_log_config, NULL);
 
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
-
 	init_revisions(&rev, prefix);
 	rev.always_show_header = 1;
 	memset(&opt, 0, sizeof(opt));
diff --git a/builtin/merge.c b/builtin/merge.c
index 7209edf..b75ae01 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1031,10 +1031,6 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 
 	git_config(git_merge_config, NULL);
 
-	/* for color.ui */
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
-
 	if (branch_mergeoptions)
 		parse_branch_merge_options(branch_mergeoptions);
 	argc = parse_options(argc, argv, prefix, builtin_merge_options,
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 4b726fa..4b480d7 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -685,9 +685,6 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 
 	git_config(git_show_branch_config, NULL);
 
-	if (showbranch_use_color == -1)
-		showbranch_use_color = git_use_color_default;
-
 	/* If nothing is specified, try the default first */
 	if (ac == 1 && default_num) {
 		ac = default_num;
diff --git a/color.c b/color.c
index ec96fe1..e8e2681 100644
--- a/color.c
+++ b/color.c
@@ -1,7 +1,7 @@
 #include "cache.h"
 #include "color.h"
 
-int git_use_color_default = 0;
+static int git_use_color_default = 0;
 int color_stdout_is_tty = -1;
 
 /*
@@ -196,12 +196,15 @@ int want_color(int var)
 {
 	static int want_auto = -1;
 
+	if (var < 0)
+		var = git_use_color_default;
+
 	if (var == GIT_COLOR_AUTO) {
 		if (want_auto < 0)
 			want_auto = check_auto_color();
 		return want_auto;
 	}
-	return var > 0;
+	return var;
 }
 
 int git_color_config(const char *var, const char *value, void *cb)
diff --git a/color.h b/color.h
index 5949bcd..3068a99 100644
--- a/color.h
+++ b/color.h
@@ -58,11 +58,6 @@ struct strbuf;
 #define GIT_COLOR_NEVER  1
 #define GIT_COLOR_AUTO   2
 
-/*
- * This variable stores the value of color.ui
- */
-extern int git_use_color_default;
-
 /* A default list of colors to use for commit graphs and show-branch output */
 extern const char *column_colors_ansi[];
 extern const int column_colors_ansi_max;
-- 
1.7.6.10.g62f04

Re: [PATCH 10/10] want_color: automatically fallback to color.ui

[Martin von Zweigbergk]

Hi Jeff,

This patch makes format-patch output color escape codes to file when
run with color.ui=always. Before the patch it did not do that. The
documentation for color.ui says "Set it to always if you want all
output not intended for machine consumption to use color". Is
format-patch "intended for machine consumption" or not?

I'm not sure why I had the parameter set to "always" instead of
"true/auto" and maybe I should change it, but since this patch changes
the behavior, I thought I should let you know (it was not mentioned in
the commit message, so I'm not sure it was intentional).


Martin

Re: [PATCH 10/10] want_color: automatically fallback to color.ui

[Jeff King]

On Sat, Sep 03, 2011 at 10:36:01PM -0400, Martin von Zweigbergk wrote:

> This patch makes format-patch output color escape codes to file when
> run with color.ui=always. Before the patch it did not do that. The
> documentation for color.ui says "Set it to always if you want all
> output not intended for machine consumption to use color". Is
> format-patch "intended for machine consumption" or not?

Sorry, this is a regression. The old behavior was that commands had to
copy color.ui's value manually into diff_use_color_default. With my
patch, the value is picked up automatically, and it is up to commands to
load or not load the specified config.

For diff plumbing versus porcelain, we have separate config code paths
(diff_basic versus diff_ui). I forgot that format-patch versus log has
the same situation, and needs the same split.

It's a long weekend here in the US, but I'll try to get a patch out on
Tuesday (and also check for any other similar regressions).

> I'm not sure why I had the parameter set to "always" instead of
> "true/auto" and maybe I should change it, but since this patch changes
> the behavior, I thought I should let you know (it was not mentioned in
> the commit message, so I'm not sure it was intentional).

Yeah, I don't think setting color.ui to "always" is all that useful. But
this behavior change was definitely not intentional. Thanks for
noticing.

-Peff

Re: [PATCH 10/10] want_color: automatically fallback to color.ui

[Steffen Daode Nurpmeso]

@ Jeff King <peff@peff.net> wrote (2011-09-04 14:53+0200):
> Sorry, this is a regression.

I should have found that.
I apologize.

--Steffen
Ciao, sdaoden(*)(gmail.com)
ASCII ribbon campaign           ( ) More nuclear fission plants
  against HTML e-mail            X    can serve more coloured
    and proprietary attachments / \     and sounding animations

Re: [PATCH 0/10] color and pager improvements

[Jeff King]

On Wed, Aug 17, 2011 at 09:58:23PM -0700, Jeff King wrote:

> While looking at the pager and color code today, I decided to tackle two
> long-standing bugs, which entailed a lot of refactoring of the color
> code. The result fixes some minor bugs, and is a little nicer for
> calling code to use.

And here are two patches on top of the previous 10 to help Ingo's
problem a bit.

  [11/10]: support pager.* for aliases
  [12/10]: support pager.* for external commands

With these, you can do "git config pager.stash false" to turn off paging
on "stash list" and "stash show" (and turn it back on with "git -p
stash list", of course).

I'm slightly tempted to allow things like "pager.stash.list" and
"pager.branch.list". It wouldn't be too hard to implement. But I'm not
sure anybody actually cares. I think Ingo's original complaint was
simply that pager.stash didn't actually do anything, not that he wanted
some separate config for the various subcommands.

-Peff

[PATCH 11/10] support pager.* for aliases

[Jeff King]

Until this patch, doing something like:

  git config alias.foo log
  git config pager.foo /some/specific/pager

would not respect pager.foo at all. With this patch, we
will use pager.foo for the "foo" alias.  We will also
fallback to pager.log if "foo" is a non-shell alias that
uses the "log" command (but any pager.foo overrides
pager.log).

Signed-off-by: Jeff King <peff@peff.net>
---
 git.c            |    3 +++
 t/t7006-pager.sh |   31 +++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/git.c b/git.c
index 8828c18..375e9b2 100644
--- a/git.c
+++ b/git.c
@@ -180,6 +180,9 @@ static int handle_alias(int *argcp, const char ***argv)
 	alias_command = (*argv)[0];
 	alias_string = alias_lookup(alias_command);
 	if (alias_string) {
+		if (use_pager == -1)
+			use_pager = check_pager_config(alias_command);
+
 		if (alias_string[0] == '!') {
 			const char **alias_argv;
 			int argc = *argcp, i;
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index 4582336..a8c6e85 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -450,4 +450,35 @@ test_expect_success TTY 'command-specific pager overridden by environment' '
 	test_cmp expect actual
 '
 
+test_expect_success TTY 'command-specific pager works for aliases' '
+	sane_unset PAGER GIT_PAGER &&
+	echo "foo:initial" >expect &&
+	>actual &&
+	test_config alias.aliaslog "log --format=%s" &&
+	test_config pager.aliaslog "sed s/^/foo:/ >actual" &&
+	test_terminal git aliaslog -1 &&
+	test_cmp expect actual
+'
+
+test_expect_success TTY 'non-shell alias falls back to command pager config' '
+	sane_unset PAGER GIT_PAGER &&
+	echo "foo:initial" >expect &&
+	>actual &&
+	test_config alias.aliaslog "log --format=%s" &&
+	test_config pager.log "sed s/^/foo:/ >actual" &&
+	test_terminal git aliaslog -1 &&
+	test_cmp expect actual
+'
+
+test_expect_success TTY 'alias-specific pager can override aliased command' '
+	sane_unset PAGER GIT_PAGER &&
+	>expect &&
+	>actual &&
+	test_config alias.aliaslog "log --format=%s" &&
+	test_config pager.log "sed s/^/log:/ >actual" &&
+	test_config pager.aliaslog false &&
+	test_terminal git aliaslog -1 &&
+	test_cmp expect actual
+'
+
 test_done
-- 
1.7.6.10.g62f04

Re: [PATCH 11/10] support pager.* for aliases

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

> Until this patch, doing something like:
>
>   git config alias.foo log
>   git config pager.foo /some/specific/pager
>
> would not respect pager.foo at all.

Is it a good thing? Looks too confusing and I am having a hard time to
decide if this is "just because we could" or "because we need to be able
to do this for such and such reasons".

Re: [PATCH 11/10] support pager.* for aliases

[Jeff King]

On Thu, Aug 18, 2011 at 03:54:46PM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > Until this patch, doing something like:
> >
> >   git config alias.foo log
> >   git config pager.foo /some/specific/pager
> >
> > would not respect pager.foo at all.
> 
> Is it a good thing? Looks too confusing and I am having a hard time to
> decide if this is "just because we could" or "because we need to be able
> to do this for such and such reasons".

I don't have a particular use for it myself. However, I don't see what's
confusing about it. Would would you expect the above commands to do with
respect to paging? I think the behavior after my patch does what users
will expect, whether they have configured pager.foo, pager.log, or
nothing.

-Peff

Re: [PATCH 11/10] support pager.* for aliases

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

>> > Until this patch, doing something like:
>> >
>> >   git config alias.foo log
>> >   git config pager.foo /some/specific/pager
>> >
>> > would not respect pager.foo at all.
>> 
>> Is it a good thing? Looks too confusing and I am having a hard time to
>> decide if this is "just because we could" or "because we need to be able
>> to do this for such and such reasons".
>
> I don't have a particular use for it myself. However, I don't see what's
> confusing about it. Would would you expect the above commands to do with
> respect to paging?

The reason I found it confusing was that I expected the "log" command that
is run as the expansion of the alias to be oblivious to the fact that the
end user called it "foo", and ignore anything specific to "foo", including
"pager.foo".

Re: [PATCH 11/10] support pager.* for aliases

[Jeff King]

On Thu, Aug 18, 2011 at 09:18:49PM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> >> > Until this patch, doing something like:
> >> >
> >> >   git config alias.foo log
> >> >   git config pager.foo /some/specific/pager
> >> >
> >> > would not respect pager.foo at all.
> >> 
> >> Is it a good thing? Looks too confusing and I am having a hard time to
> >> decide if this is "just because we could" or "because we need to be able
> >> to do this for such and such reasons".
> >
> > I don't have a particular use for it myself. However, I don't see what's
> > confusing about it. Would would you expect the above commands to do with
> > respect to paging?
> 
> The reason I found it confusing was that I expected the "log" command that
> is run as the expansion of the alias to be oblivious to the fact that the
> end user called it "foo", and ignore anything specific to "foo", including
> "pager.foo".

I think of it this way:

If the user thinks of the alias as just another form of "log", then we
do the right thing: we use log's pager config by default, and respect
pager.log. They never set pager.foo, because that is nonsensical in
their mental model.

If the user thinks of the alias as its own command, then they would
expect pager.foo to work. And it does what they expect.

But like I said, I don't personally plan on using this. It was just the
only semantics that really made sense to me, and I noticed it because of
working on externals. And clearly it's not a lot of code.

-Peff

Re: [PATCH 11/10] support pager.* for aliases

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

> On Thu, Aug 18, 2011 at 09:18:49PM -0700, Junio C Hamano wrote:
>
>> Jeff King <peff@peff.net> writes:
>> 
>> >> > Until this patch, doing something like:
>> >> >
>> >> >   git config alias.foo log
>> >> >   git config pager.foo /some/specific/pager
>> >> >
>> >> > would not respect pager.foo at all.
>> >> 
>> >> Is it a good thing? Looks too confusing and I am having a hard time to
>> >> decide if this is "just because we could" or "because we need to be able
>> >> to do this for such and such reasons".
>> >
>> > I don't have a particular use for it myself. However, I don't see what's
>> > confusing about it. Would would you expect the above commands to do with
>> > respect to paging?
>> 
>> The reason I found it confusing was that I expected the "log" command that
>> is run as the expansion of the alias to be oblivious to the fact that the
>> end user called it "foo", and ignore anything specific to "foo", including
>> "pager.foo".
>
> I think of it this way:
>
> If the user thinks of the alias as just another form of "log", then we
> do the right thing: we use log's pager config by default, and respect
> pager.log. They never set pager.foo, because that is nonsensical in
> their mental model.
>
> If the user thinks of the alias as its own command, then they would
> expect pager.foo to work. And it does what they expect.
>
> But like I said, I don't personally plan on using this. It was just the
> only semantics that really made sense to me,...

I can see that argument, but once you start paying attention to "*.foo",
you have to keep supporting that forever, and also more importantly, you
need to worry about interactions between "*.foo" vs "*.log". Which one
should win? Should they combine if both are defined? My "looks confusing"
includes that can of worms.

Re: [PATCH 11/10] support pager.* for aliases

[Junio C Hamano]

Junio C Hamano <gitster@pobox.com> writes:

>> If the user thinks of the alias as just another form of "log", then we
>> do the right thing: we use log's pager config by default, and respect
>> pager.log. They never set pager.foo, because that is nonsensical in
>> their mental model.
>>
>> If the user thinks of the alias as its own command, then they would
>> expect pager.foo to work. And it does what they expect.
>>
>> But like I said, I don't personally plan on using this. It was just the
>> only semantics that really made sense to me,...
>
> I can see that argument, but once you start paying attention to "*.foo",
> you have to keep supporting that forever, and also more importantly, you
> need to worry about interactions between "*.foo" vs "*.log". Which one
> should win? Should they combine if both are defined? My "looks confusing"
> includes that can of worms.

Actually there is another thing that I think is much worse. If the user is
trained to think of the alias as its own command by seeing pager.foo to
work as you described, you cannot blame them if they would also expect
these to work, in the sense that only "foo.*" and "bar.*" respectively
would take effect, and they would override "log.*":

	[alias]
        	foo = log
		bar = !sh -c 'log "$@"' -
	[log]
		date = default
	[foo]
        	date = iso
	[bar]
		date = relative

I do not think we want to go there.

Re: [PATCH 11/10] support pager.* for aliases

[Jeff King]

On Thu, Aug 18, 2011 at 10:23:33PM -0700, Junio C Hamano wrote:

> > I think of it this way:
> >
> > If the user thinks of the alias as just another form of "log", then we
> > do the right thing: we use log's pager config by default, and respect
> > pager.log. They never set pager.foo, because that is nonsensical in
> > their mental model.
> >
> > If the user thinks of the alias as its own command, then they would
> > expect pager.foo to work. And it does what they expect.
> >
> > But like I said, I don't personally plan on using this. It was just the
> > only semantics that really made sense to me,...
> 
> I can see that argument, but once you start paying attention to "*.foo",
> you have to keep supporting that forever, and also more importantly, you
> need to worry about interactions between "*.foo" vs "*.log". Which one
> should win? Should they combine if both are defined? My "looks confusing"
> includes that can of worms.

It seems obvious to me that the more-specific *.foo form would take
precedence over the *.log form, and anything else would be crazy. But
that is just my gut feeling. If you are confused or worried, then that
is enough for me to say it is not worth pursuing. It's not a feature I
really care about; it was more about fixing something that looked
obviously wrong while I was in the area.

-Peff

[PATCH 12/10] support pager.* for external commands

[Jeff King]

Without this patch, any commands that are not builtin would
not respect pager.* config. For example:

  git config pager.stash false
  git stash list

would still use a pager. With this patch, pager.stash now
has an effect. If it is not specified, we will still fall
back to pager.log when we invoke "log" from "stash list".

Signed-off-by: Jeff King <peff@peff.net>
---
I think we didn't do this in the original pager.* patches because of
initialization order problems. It was dangerous to look at config too
early in the process, or something similar; I don't recall the exact
problems. But since work from Jonathan and Duy last summer, I think some
of those issues have gone away. At least I couldn't find any problems.
And I have been running with this patch since last November and haven't
noticed anything odd.

 git.c            |    2 ++
 t/t7006-pager.sh |   36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 0 deletions(-)

diff --git a/git.c b/git.c
index 375e9b2..e8cff60 100644
--- a/git.c
+++ b/git.c
@@ -462,6 +462,8 @@ static void execv_dashed_external(const char **argv)
 	const char *tmp;
 	int status;
 
+	if (use_pager == -1)
+		use_pager = check_pager_config(argv[0]);
 	commit_pager_choice();
 
 	strbuf_addf(&cmd, "git-%s", argv[0]);
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index a8c6e85..742238c 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -481,4 +481,40 @@ test_expect_success TTY 'alias-specific pager can override aliased command' '
 	test_cmp expect actual
 '
 
+test_expect_success 'setup external command' '
+	cat >git-external <<-\EOF &&
+	#!/bin/sh
+	git "$@"
+	EOF
+	chmod +x git-external
+'
+
+test_expect_success TTY 'command-specific pager works for external commands' '
+	sane_unset PAGER GIT_PAGER &&
+	echo "foo:initial" >expect &&
+	>actual &&
+	test_config pager.external "sed s/^/foo:/ >actual" &&
+	test_terminal git --exec-path="`pwd`" external log --format=%s -1 &&
+	test_cmp expect actual
+'
+
+test_expect_success TTY 'sub-commands of externals use their own pager' '
+	sane_unset PAGER GIT_PAGER &&
+	echo "foo:initial" >expect &&
+	>actual &&
+	test_config pager.log "sed s/^/foo:/ >actual" &&
+	test_terminal git --exec-path=. external log --format=%s -1 &&
+	test_cmp expect actual
+'
+
+test_expect_success TTY 'external command pagers override sub-commands' '
+	sane_unset PAGER GIT_PAGER &&
+	>expect &&
+	>actual &&
+	test_config pager.external false &&
+	test_config pager.log "sed s/^/log:/ >actual" &&
+	test_terminal git --exec-path=. external log --format=%s -1 &&
+	test_cmp expect actual
+'
+
 test_done
-- 
1.7.6.10.g62f04

Re: [PATCH 12/10] support pager.* for external commands

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

> Without this patch, any commands that are not builtin would
> not respect pager.* config. For example:
>
>   git config pager.stash false
>   git stash list
>
> would still use a pager.

Unlike the [11/10] patch, I can see why this is a good change.
Thanks.

Re: [PATCH 12/10] support pager.* for external commands

[Ævar Arnfjörð Bjarmason]

On Fri, Aug 19, 2011 at 00:01, Jeff King <peff@peff.net> wrote:

> +test_expect_success TTY 'command-specific pager works for external commands' '
> +       sane_unset PAGER GIT_PAGER &&
> +       echo "foo:initial" >expect &&
> +       >actual &&
> +       test_config pager.external "sed s/^/foo:/ >actual" &&
> +       test_terminal git --exec-path="`pwd`" external log --format=%s -1 &&
> +       test_cmp expect actual

For reasons that I haven't looked into using sed like that breaks
under /usr/bin/ksh on Solaris. Just using:

    sed -e \"s/^/foo:/\"

Instead fixes it, it's not broken with /usr/xpg4/bin/sh, so it's some
ksh peculiarity.

The error it gives is:

    sed s/^/foo:/ >actual: Not found

Indicating that for some reason it's considering that whole "sed
s/^/foo:/ >actual" string to be a single command.

Re: [PATCH 12/10] support pager.* for external commands

[Jeff King]

On Sun, Feb 12, 2012 at 01:46:34AM +0100, Ævar Arnfjörð Bjarmason wrote:

> On Fri, Aug 19, 2011 at 00:01, Jeff King <peff@peff.net> wrote:
> 
> > +test_expect_success TTY 'command-specific pager works for external commands' '
> > +       sane_unset PAGER GIT_PAGER &&
> > +       echo "foo:initial" >expect &&
> > +       >actual &&
> > +       test_config pager.external "sed s/^/foo:/ >actual" &&
> > +       test_terminal git --exec-path="`pwd`" external log --format=%s -1 &&
> > +       test_cmp expect actual
> 
> For reasons that I haven't looked into using sed like that breaks
> under /usr/bin/ksh on Solaris. Just using:
> 
>     sed -e \"s/^/foo:/\"
> 
> Instead fixes it, it's not broken with /usr/xpg4/bin/sh, so it's some
> ksh peculiarity.
> 
> The error it gives is:
> 
>     sed s/^/foo:/ >actual: Not found
> 
> Indicating that for some reason it's considering that whole "sed
> s/^/foo:/ >actual" string to be a single command.

Hrm. Is the problem on the git-executing side, or is it on the setting
up the config side?

Sadly (or perhaps not) I no longer have any Solaris machines to test on.
Can you confirm that "git config pager.external" looks OK inside that
test?  Can you confirm via GIT_TRACE=1 what is being sent to the shell?

Also, it looks like we actually run commands internally from git using
"sh -c". So if it is the executing side that is wrong, I don't see how
/usr/bin/ksh would be involved at all (it would either be /bin/sh, or
/usr/xpg4/bin/sh if you have your PATH set).

-Peff

Re: [PATCH 0/10] color and pager improvements

[Ingo Brückl]

Jeff King wrote on Thu, 18 Aug 2011 14:58:20 -0700:

> I think Ingo's original complaint was simply that pager.stash didn't
> actually do anything, not that he wanted some separate config for the
> various subcommands.

No, you're wrong.

My goal was to be able to turn off paging for "stash list" only while all
other stash commands should continue paging.

It is, of course, very usefull to be able to control paging for external
commands and aliases, but in my case I originally wanted to control a
specific subcommand.

Ingo

Re: [PATCH 0/10] color and pager improvements

[Jeff King]

On Fri, Aug 19, 2011 at 12:33:01AM +0200, Ingo Brückl wrote:

> Jeff King wrote on Thu, 18 Aug 2011 14:58:20 -0700:
> 
> > I think Ingo's original complaint was simply that pager.stash didn't
> > actually do anything, not that he wanted some separate config for the
> > various subcommands.
> 
> No, you're wrong.
> 
> My goal was to be able to turn off paging for "stash list" only while all
> other stash commands should continue paging.

Ah, OK. I think the only other stash command that pages is "stash show",
but I don't think it's unreasonable to want paging for that but not for
"list".

I'll take a look at implementing something for that. Though I'll be
traveling for the next few days, so it probably won't be for a bit.

-Peff

Re: [PATCH 0/10] color and pager improvements

[Ingo Brückl]

Jeff King wrote on Thu, 18 Aug 2011 15:46:44 -0700:

> On Fri, Aug 19, 2011 at 12:33:01AM +0200, Ingo Brückl wrote:

>> My goal was to be able to turn off paging for "stash list" only while all
>> other stash commands should continue paging.

> Ah, OK. I think the only other stash command that pages is "stash show",
> but I don't think it's unreasonable to want paging for that but not for
> "list".

Maybe "stash list" simply should - like other commands - not paginate by
default.

Ingo

Re: [PATCH 0/10] color and pager improvements

[Jeff King]

On Fri, Aug 19, 2011 at 08:34:13AM +0200, Ingo Brückl wrote:

> Jeff King wrote on Thu, 18 Aug 2011 15:46:44 -0700:
> 
> > On Fri, Aug 19, 2011 at 12:33:01AM +0200, Ingo Brückl wrote:
> 
> >> My goal was to be able to turn off paging for "stash list" only while all
> >> other stash commands should continue paging.
> 
> > Ah, OK. I think the only other stash command that pages is "stash show",
> > but I don't think it's unreasonable to want paging for that but not for
> > "list".
> 
> Maybe "stash list" simply should - like other commands - not paginate by
> default.

I have no real opinion on that. It only paginates as a side effect of
calling log.

I do think "git stash show" paginating by default is probably helpful,
though.

The best way to get people's attention is probably to post a patch
adding --no-pager to the git-log invocation of "git stash list". :)

-Peff

Re: [PATCH 0/10] color and pager improvements

[Steffen Daode Nurpmeso]

@ Jeff King <peff@peff.net> wrote (2011-08-18 06:58+0200):
> These three fix the problem Steffen mentioned here:

Uuuh, such a shame - you know that it was first noted by
Benjamin Kudria (2008-07-23,
http://marc.info/?l=git&m=121677902502581&w=2).
And it was you who tried to resurrect the same issue last year.
(The thing is: i did not search the archive first because it was
clearly a bug.  I did once you referred to your older patch.)
But great that you actually found the time to fix it!

(I must admit though that i'm currently addicted to the coloured
output, because simply switching between my terms gives a clear
indication of where i'm currently git(1)ing.  :->  And that in
turn is something which gives more and more fun the longer i use
it!  It is *really* fantastic once you get used to it.  And do
gc --aggressive and all your temporary fooling is cleaned up.)

Now it's pretty unfortunate that i cannot offer fixes for
anything.

I have a dumb patch of 'rebase -i' which includes the TODO entry
line ($rest) as a comment in the commit message, which is pretty
useful because i think about the rebase task and can store
comments in that very line.  But it introduces commit
--cleanup=strip and patches commit.c to add a --message-prefix
option.  This is no good yet.

Michael J Gruber's today's shocking exercise on the german
keyboard layout - maybe i should really resurrect parts of that
NBSP series?

And referring to one sentence of yours from the past: no, refspec
stuff *is* that hard: they are not a tree which is created via
'refs_build_tree(); refs_merge_command_line();' upon program
start, with pointers to maybe instantiated .. whatever.
/*
 * Note. This is used only by "push"; refspec matching rules for
 * push and fetch are subtly different, so do not try to reuse it
 * without thinking.
 */
I gave up once i found that (in remote.c).  (AFAIR it seems
refspecs are first build L->R, then pushed, then build again but
in R->L direction.  Which is why without a fetch= the remotes/
ref is not updated after a push.  AFAIK - i gave up ...)

But i'm looking forward and really hope to be able to contribute
some useful and good stuff to great projects in the future.
OpenBSD, for example.  :-)

--Steffen
Ciao, sdaoden(*)(gmail.com)
ASCII ribbon campaign           ( ) More nuclear fission plants
  against HTML e-mail            X    can serve more coloured
    and proprietary attachments / \     and sounding animations

Re: [PATCH 0/10] color and pager improvements

[Junio C Hamano]

Nicely done.