Use gitattributes to define per-path whitespace rule

The `core.whitespace` configuration variable allows you to define what
`diff` and `apply` should consider whitespace errors for all paths in
the project (See gitlink:git-config[1]).  This attribute gives you finer
control per path.

For example, if you have these in the .gitattributes:

    frotz   whitespace
    nitfol  -whitespace
    xyzzy   whitespace=-trailing

all types of whitespace problems known to git are noticed in path 'frotz'
(i.e. diff shows them in diff.whitespace color, and apply warns about
them), no whitespace problem is noticed in path 'nitfol', and the
default types of whitespace problems except "trailing whitespace" are
noticed for path 'xyzzy'.  A project with mixed Python and C might want
to have:

    *.c    whitespace
    *.py   whitespace=-indent-with-non-tab

in its toplevel .gitattributes file.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 66 insertions, 1 deletions

diff --git a/t/t4019-diff-wserror.sh b/t/t4019-diff-wserror.sh
index dbc895b9b..67e080bdb 100755
--- a/t/t4019-diff-wserror.sh
+++ b/t/t4019-diff-wserror.sh
@@ -45,8 +45,24 @@ test_expect_success 'without -trail' '
 
 '
 
+test_expect_success 'without -trail (attribute)' '
+
+	git config --unset core.whitespace
+	echo "F whitespace=-trail" >.gitattributes
+	git diff --color >output
+	grep "$blue_grep" output >error
+	grep -v "$blue_grep" output >normal
+
+	grep Eight normal >/dev/null &&
+	grep HT error >/dev/null &&
+	grep With normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
 test_expect_success 'without -space' '
 
+	rm -f .gitattributes
 	git config core.whitespace -space
 	git diff --color >output
 	grep "$blue_grep" output >error
@@ -59,8 +75,24 @@ test_expect_success 'without -space' '
 
 '
 
+test_expect_success 'without -space (attribute)' '
+
+	git config --unset core.whitespace
+	echo "F whitespace=-space" >.gitattributes
+	git diff --color >output
+	grep "$blue_grep" output >error
+	grep -v "$blue_grep" output >normal
+
+	grep Eight normal >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With error >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
 test_expect_success 'with indent-non-tab only' '
 
+	rm -f .gitattributes
 	git config core.whitespace indent,-trailing,-space
 	git diff --color >output
 	grep "$blue_grep" output >error
@@ -73,4 +105,19 @@ test_expect_success 'with indent-non-tab only' '
 
 '
 
+test_expect_success 'with indent-non-tab only (attribute)' '
+
+	git config --unset core.whitespace
+	echo "F whitespace=indent,-trailing,-space" >.gitattributes
+	git diff --color >output
+	grep "$blue_grep" output >error
+	grep -v "$blue_grep" output >normal
+
+	grep Eight error >/dev/null &&
+	grep HT normal >/dev/null &&
+	grep With normal >/dev/null &&
+	grep No normal >/dev/null
+
+'
+
 test_done
diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
index f53ac466d..85f3da2b9 100755
--- a/t/t4124-apply-ws-rule.sh
+++ b/t/t4124-apply-ws-rule.sh
@@ -112,6 +112,15 @@ test_expect_success 'whitespace=error-all, no rule' '
 
 '
 
+test_expect_success 'whitespace=error-all, no rule (attribute)' '
+
+	git config --unset core.whitespace &&
+	echo "target -whitespace" >.gitattributes &&
+	apply_patch --whitespace=error-all &&
+	diff file target
+
+'
+
 for t in - ''
 do
 	case "$t" in '') tt='!' ;; *) tt= ;; esac
@@ -121,11 +130,20 @@ do
 		for i in - ''
 		do
 			case "$i" in '') ti='#' ;; *) ti= ;; esac
-			rule=${t}trailing,${s}space,${i}indent &&
+			rule=${t}trailing,${s}space,${i}indent
+
+			rm -f .gitattributes
 			test_expect_success "rule=$rule" '
 				git config core.whitespace "$rule" &&
 				test_fix "$tt$ts$ti"
 			'
+
+			test_expect_success "rule=$rule (attributes)" '
+				git config --unset core.whitespace &&
+				echo "target whitespace=$rule" >.gitattributes &&
+				test_fix "$tt$ts$ti"
+			'
+
 		done
 	done
 done