Merge branch 'jc/attr'

* jc/attr:
  Add 'filter' attribute and external filter driver definition.
  Add 'ident' conversion.

t/t0021-conversion.sh

@@ -0,0 +1,48 @@
+#!/bin/sh
+
+test_description='blob conversion via gitattributes'
+
+. ./test-lib.sh
+
+cat <<\EOF >rot13.sh
+tr '[a-zA-Z]' '[n-za-mN-ZA-M]'
+EOF
+chmod +x rot13.sh
+
+test_expect_success setup '
+	git config filter.rot13.smudge ./rot13.sh &&
+	git config filter.rot13.clean ./rot13.sh &&
+
+	{
+	    echo "*.t filter=rot13"
+	    echo "*.i ident"
+	} >.gitattributes &&
+
+	{
+	    echo a b c d e f g h i j k l m
+	    echo n o p q r s t u v w x y z
+	    echo '\''$ident$'\''
+	} >test &&
+	cat test >test.t &&
+	cat test >test.o &&
+	cat test >test.i &&
+	git add test test.t test.i &&
+	rm -f test test.t test.i &&
+	git checkout -- test test.t test.i
+'
+
+script='s/^\$ident: \([0-9a-f]*\) \$/\1/p'
+
+test_expect_success check '
+
+	cmp test.o test &&
+	cmp test.o test.t &&
+
+	# ident should be stripped in the repository
+	git diff --raw --exit-code :test :test.i &&
+	id=$(git rev-parse --verify :test) &&
+	embedded=$(sed -ne "$script" test.i) &&
+	test "z$id" = "z$embedded"
+'
+
+test_done