Make the tab width used for whitespace checks configurable

A new whitespace "rule" is added that sets the tab width to use for
whitespace checks and fix-ups and replaces the hard-coded constant 8.

Since the setting is part of the rules, it can be set per file using
.gitattributes.

The new configuration is backwards compatible because older git versions
simply ignore unknown whitespace rules.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 85 insertions, 0 deletions

diff --git a/t/t4019-diff-wserror.sh b/t/t4019-diff-wserror.sh
index f7c85ec604..6f992c88eb 100755
--- a/t/t4019-diff-wserror.sh
+++ b/t/t4019-diff-wserror.sh
@@ -51,8 +51,65 @@ test_expect_success default '
 
 '
 
+test_expect_success 'default (attribute)' '
+
+	test_might_fail git config --unset core.whitespace &&
+	echo "F whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight error >/dev/null &&
+	grep HT error >/dev/null &&
+	grep With error >/dev/null &&
+	grep Return error >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'default, tabwidth=10 (attribute)' '
+
+	git config core.whitespace "tabwidth=10" &&
+	echo "F whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT error >/dev/null &&
+	grep With error >/dev/null &&
+	grep Return error >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'no check (attribute)' '
+
+	test_might_fail git config --unset core.whitespace &&
+	echo "F -whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'no check, tabwidth=10 (attribute), must be irrelevant' '
+
+	git config core.whitespace "tabwidth=10" &&
+	echo "F -whitespace" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
 test_expect_success 'without -trail' '
 
+	rm -f .gitattributes &&
 	git config core.whitespace -trail &&
 	prepare_output &&
 
@@ -134,6 +191,34 @@ test_expect_success 'with indent-non-tab only (attribute)' '
 
 '
 
+test_expect_success 'with indent-non-tab only, tabwidth=10' '
+
+	rm -f .gitattributes &&
+	git config core.whitespace indent,tabwidth=10,-trailing,-space &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
+test_expect_success 'with indent-non-tab only, tabwidth=10 (attribute)' '
+
+	test_might_fail git config --unset core.whitespace &&
+	echo "F whitespace=indent,-trailing,-space,tabwidth=10" >.gitattributes &&
+	prepare_output &&
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep Return normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
 test_expect_success 'with cr-at-eol' '
 
 	rm -f .gitattributes &&