Merge branch 'jc/update-index-show-index-version'

"git update-index" learns "--show-index-version" to inspect
the index format version used by the on-disk index file.

* jc/update-index-show-index-version:
  test-tool: retire "index-version"
  update-index: add --show-index-version
  update-index doc: v4 is OK with JGit and libgit2

t/helper/test-index-version.c

@@ -1,15 +0,0 @@
-#include "test-tool.h"
-#include "read-cache-ll.h"
-
-int cmd__index_version(int argc UNUSED, const char **argv UNUSED)
-{
-	struct cache_header hdr;
-	int version;
-
-	memset(&hdr,0,sizeof(hdr));
-	if (read(0, &hdr, sizeof(hdr)) != sizeof(hdr))
-		return 0;
-	version = ntohl(hdr.hdr_version);
-	printf("%d\n", version);
-	return 0;
-}

t/helper/test-tool.c

@@ -38,7 +38,6 @@ static struct test_cmd cmds[] = {
 	{ "hashmap", cmd__hashmap },
 	{ "hash-speed", cmd__hash_speed },
 	{ "hexdump", cmd__hexdump },
-	{ "index-version", cmd__index_version },
 	{ "json-writer", cmd__json_writer },
 	{ "lazy-init-name-hash", cmd__lazy_init_name_hash },
 	{ "match-trees", cmd__match_trees },

t/helper/test-tool.h

@@ -32,7 +32,6 @@ int cmd__getcwd(int argc, const char **argv);
 int cmd__hashmap(int argc, const char **argv);
 int cmd__hash_speed(int argc, const char **argv);
 int cmd__hexdump(int argc, const char **argv);
-int cmd__index_version(int argc, const char **argv);
 int cmd__json_writer(int argc, const char **argv);
 int cmd__lazy_init_name_hash(int argc, const char **argv);
 int cmd__match_trees(int argc, const char **argv);

t/t1600-index.sh

@@ -118,7 +118,7 @@ test_index_version () {
 		fi &&
 		git add a &&
 		echo $EXPECTED_OUTPUT_VERSION >expect &&
-		test-tool index-version <.git/index >actual &&
+		git update-index --show-index-version >actual &&
 		test_cmp expect actual
 	)
 }

t/t1700-split-index.sh

@@ -43,7 +43,7 @@ test_expect_success 'enable split index' '
 	git config splitIndex.maxPercentChange 100 &&
 	git update-index --split-index &&
 	test-tool dump-split-index .git/index >actual &&
-	indexversion=$(test-tool index-version <.git/index) &&
+	indexversion=$(git update-index --show-index-version) &&
 
 	# NEEDSWORK: Stop hard-coding checksums.
 	if test "$indexversion" = "4"

t/t2104-update-index-skip-worktree.sh

@@ -39,7 +39,7 @@ test_expect_success 'setup' '
 '
 
 test_expect_success 'index is at version 2' '
-	test "$(test-tool index-version < .git/index)" = 2
+	test "$(git update-index --show-index-version)" = 2
 '
 
 test_expect_success 'update-index --skip-worktree' '
@@ -48,7 +48,7 @@ test_expect_success 'update-index --skip-worktree' '
 '
 
 test_expect_success 'index is at version 3 after having some skip-worktree entries' '
-	test "$(test-tool index-version < .git/index)" = 3
+	test "$(git update-index --show-index-version)" = 3
 '
 
 test_expect_success 'ls-files -t' '
@@ -61,7 +61,7 @@ test_expect_success 'update-index --no-skip-worktree' '
 '
 
 test_expect_success 'index version is back to 2 when there is no skip-worktree entry' '
-	test "$(test-tool index-version < .git/index)" = 2
+	test "$(git update-index --show-index-version)" = 2
 '
 
 test_done

t/t2107-update-index-basic.sh

@@ -111,4 +111,35 @@ test_expect_success '--chmod=+x and chmod=-x in the same argument list' '
 	test_cmp expect actual
 '
 
+test_expect_success '--index-version' '
+	git commit --allow-empty -m snap &&
+	git reset --hard &&
+	git rm -f -r --cached . &&
+
+	# The default index version is 2 --- update this test
+	# when you change it in the code
+	git update-index --show-index-version >actual &&
+	echo 2 >expect &&
+	test_cmp expect actual &&
+
+	# The next test wants us to be using version 2
+	git update-index --index-version 2 &&
+
+	git update-index --index-version 4 --verbose >actual &&
+	echo "index-version: was 2, set to 4" >expect &&
+	test_cmp expect actual &&
+
+	git update-index --index-version 4 --verbose >actual &&
+	echo "index-version: was 4, set to 4" >expect &&
+	test_cmp expect actual &&
+
+	git update-index --index-version 2 --verbose >actual &&
+	echo "index-version: was 4, set to 2" >expect &&
+	test_cmp expect actual &&
+
+	# non-verbose should be silent
+	git update-index --index-version 4 >actual &&
+	test_must_be_empty actual
+'
+
 test_done