dir: hide untracked contents of untracked dirs

When we taught read_directory_recursive() to recurse into untracked
directories in search of ignored files given DIR_SHOW_IGNORED_TOO, that
had the side effect of teaching it to collect the untracked contents of
untracked directories. It doesn't always make sense to return these,
though (we do need them for `clean -d`), so we introduce a flag
(DIR_KEEP_UNTRACKED_CONTENTS) to control whether or not read_directory()
strips dir->entries of the untracked contents of untracked dirs.

We also introduce check_contains() to check if one dir_entry corresponds
to a path which contains the path corresponding to another dir_entry.

This also fixes known breakages in t7061, since status --ignored now
searches untracked directories for ignored files.

Signed-off-by: Samuel Lijin <sxlijin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/dir.c b/dir.c
index 6b4eeef584..61561ea91d 100644
--- a/dir.c
+++ b/dir.c
@@ -1813,6 +1813,14 @@ static int cmp_name(const void *p1, const void *p2)
 	return name_compare(e1->name, e1->len, e2->name, e2->len);
 }
 
+/* check if *out lexically strictly contains *in */
+static int check_contains(const struct dir_entry *out, const struct dir_entry *in)
+{
+	return (out->len < in->len) &&
+		(out->name[out->len - 1] == '/') &&
+		!memcmp(out->name, in->name, out->len);
+}
+
 static int treat_leading_path(struct dir_struct *dir,
 			      const char *path, int len,
 			      const struct pathspec *pathspec)
@@ -2028,6 +2036,29 @@ int read_directory(struct dir_struct *dir, const char *path,
 		read_directory_recursive(dir, path, len, untracked, 0, pathspec);
 	QSORT(dir->entries, dir->nr, cmp_name);
 	QSORT(dir->ignored, dir->ignored_nr, cmp_name);
+
+	/*
+	 * If DIR_SHOW_IGNORED_TOO is set, read_directory_recursive() will
+	 * also pick up untracked contents of untracked dirs; by default
+	 * we discard these, but given DIR_KEEP_UNTRACKED_CONTENTS we do not.
+	 */
+	if ((dir->flags & DIR_SHOW_IGNORED_TOO) &&
+		     !(dir->flags & DIR_KEEP_UNTRACKED_CONTENTS)) {
+		int i, j;
+
+		/* remove from dir->entries untracked contents of untracked dirs */
+		for (i = j = 0; j < dir->nr; j++) {
+			if (i && check_contains(dir->entries[i - 1], dir->entries[j])) {
+				free(dir->entries[j]);
+				dir->entries[j] = NULL;
+			} else {
+				dir->entries[i++] = dir->entries[j];
+			}
+		}
+
+		dir->nr = i;
+	}
+
 	if (dir->untracked) {
 		static struct trace_key trace_untracked_stats = TRACE_KEY_INIT(UNTRACKED_STATS);
 		trace_printf_key(&trace_untracked_stats,