[PATCH 3/8] 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             | 5 +++++
 2 files changed, 13 insertions(+), 1 deletion(-)

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 246b3d3..ecb685d 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -40,6 +40,7 @@ enum uc_mode {
 	UNDEF_UC = -1,
 	NO_UC = 0,
 	UC,
+	TEST_UC,
 	FORCE_UC
 };
 
@@ -1004,6 +1005,8 @@ 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"), TEST_UC),
 		OPT_SET_INT(0, "force-untracked-cache", &untracked_cache,
 			    N_("enable untracked cache without testing the filesystem"), FORCE_UC),
 		OPT_END()
@@ -1119,6 +1122,8 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 			setup_work_tree();
 			if (!test_if_untracked_cache_is_supported())
 				return 1;
+			if (untracked_cache == TEST_UC)
+				return 0;
 		}
 		if (!the_index.untracked) {
 			uc = xcalloc(1, sizeof(*uc));
-- 
2.6.3.478.g9f95483.dirty