Merge branch 'jk/color-and-pager'

* jk/color-and-pager:
  want_color: automatically fallback to color.ui
  diff: don't load color config in plumbing
  config: refactor get_colorbool function
  color: delay auto-color decision until point of use
  git_config_colorbool: refactor stdout_is_tty handling
  diff: refactor COLOR_DIFF from a flag into an int
  setup_pager: set GIT_PAGER_IN_USE
  t7006: use test_config helpers
  test-lib: add helper functions for config
  t7006: modernize calls to unset

Conflicts:
	builtin/commit.c
	parse-options.c

2 files changed, 61 insertions, 23 deletions

diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index ed7575d0f..458233693 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 &&
 
 	(
@@ -170,9 +167,21 @@ 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 &&
-	git config color.ui auto ||
+	test_config color.ui auto ||
 	cleanup_fail &&
 
 	(
@@ -184,6 +193,17 @@ 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
@@ -221,7 +241,7 @@ 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 +264,7 @@ 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 +297,7 @@ 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 +327,7 @@ 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 +344,7 @@ 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 &&
@@ -402,21 +422,21 @@ 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 &&
-	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
 '
 
 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"
-	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 +445,7 @@ 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
 '
diff --git a/t/test-lib.sh b/t/test-lib.sh
index e27422217..d7dfc8b0b 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -361,6 +361,24 @@ 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 unset
+		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:
 #