Teach '--cached' option to check-attr

This option causes check-attr to consider .gitattributes only from
the index, ignoring .gitattributes from the working tree. This allows
the command to be used in situations where a working tree does not exist.

Signed-off-by: Jay Soffian <jaysoffian@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-check-attr.txt

@@ -24,6 +24,9 @@ OPTIONS
 	paths.  If this option is used, then 'unspecified' attributes
 	will not be included in the output.
 
+--cached::
+	Consider `.gitattributes` in the index only, ignoring the working tree.
+
 --stdin::
 	Read file names from stdin instead of from the command-line.
 

builtin/check-attr.c

@@ -5,6 +5,7 @@
 #include "parse-options.h"
 
 static int all_attrs;
+static int cached_attrs;
 static int stdin_paths;
 static const char * const check_attr_usage[] = {
 "git check-attr [-a | --all | attr...] [--] pathname...",
@@ -16,6 +17,7 @@ static int null_term_line;
 
 static const struct option check_attr_options[] = {
 	OPT_BOOLEAN('a', "all", &all_attrs, "report all attributes set on file"),
+	OPT_BOOLEAN(0,  "cached", &cached_attrs, "use .gitattributes only from the index"),
 	OPT_BOOLEAN(0 , "stdin", &stdin_paths, "read file names from stdin"),
 	OPT_BOOLEAN('z', NULL, &null_term_line,
 		"input paths are terminated by a null character"),
@@ -99,6 +101,9 @@ int cmd_check_attr(int argc, const char **argv, const char *prefix)
 		die("invalid cache");
 	}
 
+	if (cached_attrs)
+		git_attr_set_direction(GIT_ATTR_INDEX, NULL);
+
 	doubledash = -1;
 	for (i = 0; doubledash < 0 && i < argc; i++) {
 		if (!strcmp(argv[i], "--"))

t/t0003-attributes.sh

@@ -134,10 +134,20 @@ test_expect_success 'attribute test: read paths from stdin' '
 
 test_expect_success 'attribute test: --all option' '
 
-	grep -v unspecified < expect-all | sort > expect &&
-	sed -e "s/:.*//" < expect-all | uniq |
-		git check-attr --stdin --all | sort > actual &&
-	test_cmp expect actual
+	grep -v unspecified <expect-all | sort >specified-all &&
+	sed -e "s/:.*//" <expect-all | uniq >stdin-all &&
+	git check-attr --stdin --all <stdin-all | sort >actual &&
+	test_cmp specified-all actual
+'
+
+test_expect_success 'attribute test: --cached option' '
+
+	: >empty &&
+	git check-attr --cached --stdin --all <stdin-all | sort >actual &&
+	test_cmp empty actual &&
+	git add .gitattributes a/.gitattributes a/b/.gitattributes &&
+	git check-attr --cached --stdin --all <stdin-all | sort >actual &&
+	test_cmp specified-all actual
 '
 
 test_expect_success 'root subdir attribute test' '
@@ -168,6 +178,13 @@ test_expect_success 'bare repository: check that .gitattribute is ignored' '
 
 '
 
+test_expect_success 'bare repository: check that --cached honors index' '
+	GIT_INDEX_FILE=../.git/index \
+	git check-attr --cached --stdin --all <../stdin-all |
+	sort >actual &&
+	test_cmp ../specified-all actual
+'
+
 test_expect_success 'bare repository: test info/attributes' '
 
 	(