untracked-cache: support sparse checkout

Remove a check that would disable the untracked cache for sparse
checkouts.  Add tests that ensure that the untracked cache works with
sparse checkouts -- specifically considering the case that a file
foo/bar is checked out, but foo/.gitignore is not.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 14 deletions

diff --git a/dir.c b/dir.c
index 8209f8b8af..e7b89fe6fe 100644
--- a/dir.c
+++ b/dir.c
@@ -1078,10 +1078,9 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 		    (!untracked || !untracked->valid ||
 		     /*
 		      * .. and .gitignore does not exist before
-		      * (i.e. null exclude_sha1 and skip_worktree is
-		      * not set). Then we can skip loading .gitignore,
-		      * which would result in ENOENT anyway.
-		      * skip_worktree is taken care in read_directory()
+		      * (i.e. null exclude_sha1). Then we can skip
+		      * loading .gitignore, which would result in
+		      * ENOENT anyway.
 		      */
 		     !is_null_sha1(untracked->exclude_sha1))) {
 			/*
@@ -1880,7 +1879,6 @@ static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *d
 						      const struct pathspec *pathspec)
 {
 	struct untracked_cache_dir *root;
-	int i;
 
 	if (!dir->untracked || getenv("GIT_DISABLE_UNTRACKED_CACHE"))
 		return NULL;
@@ -1932,15 +1930,6 @@ static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *d
 	if (dir->exclude_list_group[EXC_CMDL].nr)
 		return NULL;
 
-	/*
-	 * An optimization in prep_exclude() does not play well with
-	 * CE_SKIP_WORKTREE. It's a rare case anyway, if a single
-	 * entry has that bit set, disable the whole untracked cache.
-	 */
-	for (i = 0; i < active_nr; i++)
-		if (ce_skip_worktree(active_cache[i]))
-			return NULL;
-
 	if (!ident_in_untracked(dir->untracked)) {
 		warning(_("Untracked cache is disabled on this system."));
 		return NULL;