dir.c: make 'git-status --ignored' work within leading directories

'git-status --ignored path/' doesn't list ignored files and directories
within 'path' if some component of 'path' is classified as untracked.

Disable the DIR_SHOW_OTHER_DIRECTORIES flag while traversing leading
directories. This prevents treat_leading_path() with DIR_SHOW_IGNORED flag
from aborting at the top level untracked directory.

As a side effect, this also eliminates a recursive directory scan per
leading directory level, as treat_directory() can no longer call
read_directory_recursive() when called from treat_leading_path().

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

dir.c

@@ -1447,12 +1447,14 @@ static int treat_leading_path(struct dir_struct *dir,
 	struct strbuf sb = STRBUF_INIT;
 	int baselen, rc = 0;
 	const char *cp;
+	int old_flags = dir->flags;
 
 	while (len && path[len - 1] == '/')
 		len--;
 	if (!len)
 		return 1;
 	baselen = 0;
+	dir->flags &= ~DIR_SHOW_OTHER_DIRECTORIES;
 	while (1) {
 		cp = path + baselen + !!baselen;
 		cp = memchr(cp, '/', path + len - cp);
@@ -1475,6 +1477,7 @@ static int treat_leading_path(struct dir_struct *dir,
 		}
 	}
 	strbuf_release(&sb);
+	dir->flags = old_flags;
 	return rc;
 }
 

t/t7061-wtstatus-ignore.sh

@@ -32,6 +32,25 @@ test_expect_success 'status untracked directory with --ignored -u' '
 	git status --porcelain --ignored -u >actual &&
 	test_cmp expected actual
 '
+cat >expected <<\EOF
+?? untracked/uncommitted
+!! untracked/ignored
+EOF
+
+test_expect_success 'status prefixed untracked directory with --ignored' '
+	git status --porcelain --ignored untracked/ >actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<\EOF
+?? untracked/uncommitted
+!! untracked/ignored
+EOF
+
+test_expect_success 'status prefixed untracked sub-directory with --ignored -u' '
+	git status --porcelain --ignored -u untracked/ >actual &&
+	test_cmp expected actual
+'
 
 cat >expected <<\EOF
 ?? .gitignore