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>

1 files changed, 19 insertions, 1 deletions

diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
index f53ac466d6..85f3da2b98 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