[RFC/PATCH 2/8] update-index: add --test-untracked-cache

[Christian Couder <christian.couder@gmail.com>]

It is nice to just be able to test if untracked cache is
supported without enabling it.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 Documentation/git-update-index.txt | 9 ++++++++-
 builtin/update-index.c             | 8 ++++++--
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index 3df9c26..0ff7396 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -17,7 +17,7 @@ SYNOPSIS
 	     [--[no-]assume-unchanged]
 	     [--[no-]skip-worktree]
 	     [--ignore-submodules]
-	     [--[no-|force-]untracked-cache]
+	     [--[no-|test-|force-]untracked-cache]
 	     [--really-refresh] [--unresolve] [--again | -g]
 	     [--info-only] [--index-info]
 	     [-z] [--stdin] [--index-version <n>]
@@ -179,6 +179,13 @@ may not support it yet.
 	system must change `st_mtime` field of a directory if files
 	are added or deleted in that directory.
 
+--test-untracked-cache::
+	Only perform tests on the working directory to make sure
+	untracked cache can be used. You have to manually enable
+	untracked cache using `--force-untracked-cache` (or
+	`--untracked-cache` but this will run the tests again)
+	afterwards if you really want to use it.
+
 --force-untracked-cache::
 	For safety, `--untracked-cache` performs tests on the working
 	directory to make sure untracked cache can be used. These
diff --git a/builtin/update-index.c b/builtin/update-index.c
index e568acc..b7b5108 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -996,8 +996,10 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 			N_("enable or disable split index")),
 		OPT_BOOL(0, "untracked-cache", &untracked_cache,
 			N_("enable/disable untracked cache")),
+		OPT_SET_INT(0, "test-untracked-cache", &untracked_cache,
+			    N_("test if the filesystem supports untracked cache"), 2),
 		OPT_SET_INT(0, "force-untracked-cache", &untracked_cache,
-			    N_("enable untracked cache without testing the filesystem"), 2),
+			    N_("enable untracked cache without testing the filesystem"), 3),
 		OPT_END()
 	};
 
@@ -1107,10 +1109,12 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 	if (untracked_cache > 0) {
 		struct untracked_cache *uc;
 
-		if (untracked_cache < 2) {
+		if (untracked_cache < 3) {
 			setup_work_tree();
 			if (!test_if_untracked_cache_is_supported())
 				return 1;
+			if (untracked_cache == 2)
+				return 0;
 		}
 		if (!the_index.untracked) {
 			uc = xcalloc(1, sizeof(*uc));
-- 
2.6.3.391.g95a3a5c