dir.c: git-clean -d -X: don't delete tracked directories

The notion of "ignored tracked" directories introduced in 721ac4e "dir.c:
Make git-status --ignored more consistent" has a few unwanted side effects:

 - git-clean -d -X: deletes ignored tracked directories. git-clean should
   never delete tracked content.

 - git-ls-files --ignored --other --directory: lists ignored tracked
   directories instead of "other" directories.

 - git-status --ignored: lists ignored tracked directories while contained
   files may be listed as modified. Paths listed by git-status should be
   disjoint (except in long format where a path may be listed in both the
   staged and unstaged section).

Additionally, the current behaviour violates documentation in gitignore(5)
("Specifies intentionally *untracked* files to ignore") and Documentation/
technical/api-directory-listing.txt ("DIR_SHOW_OTHER_DIRECTORIES: Include
a directory that is *not tracked*.").

In dir.c::treat_directory, remove the special handling of ignored tracked
directories, so that the DIR_SHOW_OTHER_DIRECTORIES flag only affects
"other" (i.e. untracked) directories. In dir.c::dir_add_name, check that
added paths are untracked even if DIR_SHOW_IGNORED is set.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

dir.c

@@ -941,8 +941,7 @@ static struct dir_entry *dir_entry_new(const char *pathname, int len)
 
 static struct dir_entry *dir_add_name(struct dir_struct *dir, const char *pathname, int len)
 {
-	if (!(dir->flags & DIR_SHOW_IGNORED) &&
-	    cache_name_exists(pathname, len, ignore_case))
+	if (cache_name_exists(pathname, len, ignore_case))
 		return NULL;
 
 	ALLOC_GROW(dir->entries, dir->nr+1, dir->alloc);
@@ -1044,9 +1043,8 @@ static enum exist_status directory_exists_in_index(const char *dirname, int len)
  * traversal routine.
  *
  * Case 1: If we *already* have entries in the index under that
- * directory name, we recurse into the directory to see all the files,
- * unless the directory is excluded and we want to show ignored
- * directories
+ * directory name, we always recurse into the directory to see
+ * all the files.
  *
  * Case 2: If we *already* have that directory name as a gitlink,
  * we always continue to see it as a gitlink, regardless of whether
@@ -1081,9 +1079,6 @@ static enum directory_treatment treat_directory(struct dir_struct *dir,
 	/* The "len-1" is to strip the final '/' */
 	switch (directory_exists_in_index(dirname, len-1)) {
 	case index_directory:
-		if ((dir->flags & DIR_SHOW_OTHER_DIRECTORIES) && exclude)
-			break;
-
 		return recurse_into_directory;
 
 	case index_gitdir:

t/t3001-ls-files-others-exclude.sh

@@ -237,6 +237,32 @@ test_expect_success 'hide empty ignored directory with --no-empty-directory' '
 	test_cmp expect actual
 '
 
+test_expect_success 'show/hide empty ignored sub-directory (setup)' '
+	> top/l1/tracked &&
+	(
+		cd top &&
+		git add -f l1/tracked
+	)
+'
+
+test_expect_success 'show empty ignored sub-directory with --directory' '
+	(
+		cd top &&
+		git ls-files -o -i --exclude l1 --directory
+	) >actual &&
+	echo l1/l2/ >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'hide empty ignored sub-directory with --no-empty-directory' '
+	(
+		cd top &&
+		git ls-files -o -i --exclude l1 --directory --no-empty-directory
+	) >actual &&
+	>expect &&
+	test_cmp expect actual
+'
+
 test_expect_success 'pattern matches prefix completely' '
 	: >expect &&
 	git ls-files -i -o --exclude "/three/a.3[abc]" >actual &&

t/t7061-wtstatus-ignore.sh

@@ -186,7 +186,7 @@ cat >expected <<\EOF
 ?? .gitignore
 ?? actual
 ?? expected
-!! tracked/
+!! tracked/uncommitted
 EOF
 
 test_expect_success 'status ignored tracked directory and uncommitted file with --ignore' '
@@ -212,7 +212,7 @@ cat >expected <<\EOF
 ?? .gitignore
 ?? actual
 ?? expected
-!! tracked/
+!! tracked/ignored/
 EOF
 
 test_expect_success 'status ignored tracked directory with uncommitted file in untracked subdir with --ignore' '
@@ -239,7 +239,7 @@ cat >expected <<\EOF
 ?? .gitignore
 ?? actual
 ?? expected
-!! tracked/
+!! tracked/ignored/uncommitted
 EOF
 
 test_expect_success 'status ignored tracked directory with uncommitted file in tracked subdir with --ignore' '

t/t7300-clean.sh

@@ -298,6 +298,23 @@ test_expect_success 'git clean -d -x' '
 
 '
 
+test_expect_success 'git clean -d -x with ignored tracked directory' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c docs/manual.txt obj.o build/lib.so &&
+	git clean -d -x -e src &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test ! -f a.out &&
+	test -f src/part3.c &&
+	test ! -d docs &&
+	test ! -f obj.o &&
+	test ! -d build
+
+'
+
 test_expect_success 'git clean -X' '
 
 	mkdir -p build docs &&
@@ -332,6 +349,23 @@ test_expect_success 'git clean -d -X' '
 
 '
 
+test_expect_success 'git clean -d -X with ignored tracked directory' '
+
+	mkdir -p build docs &&
+	touch a.out src/part3.c docs/manual.txt obj.o build/lib.so &&
+	git clean -d -X -e src &&
+	test -f Makefile &&
+	test -f README &&
+	test -f src/part1.c &&
+	test -f src/part2.c &&
+	test -f a.out &&
+	test ! -f src/part3.c &&
+	test -f docs/manual.txt &&
+	test ! -f obj.o &&
+	test ! -d build
+
+'
+
 test_expect_success 'clean.requireForce defaults to true' '
 
 	git config --unset clean.requireForce &&